POLYESTER REPAIR MANUAL

Transcription

1 POLYESTER REPAIR MANUAL EIGHTH EDITION JUNE 2017 Allied Piano and Finish LLC 3096 Bristol Road Warrington, PA

2 Table of Contents Product and Tool Reference Guide Quick Repair Guide... 8 Introduction... 9 Overview Assessing the Situation Is It Really Polyester? Testing on Black and White Finishes Testing on Clear Coat Wood Finishes Polishing and Sanding Exercise for Beginners Getting to Know What Each Step Looks Like Step 7: Final Finish Liquid Step 6: Polishing Paste Step 5: AP2 Compound Paste Step 4: AP1 Compound Paste Step 3: 1200 Wet/Dry Sandpaper Step 2: 1000 Wet/Dry Sandpaper Step 1: 600 Wet/Dry Sandpaper Sanding and Polishing Technique From a 600 Grit Scratch Pattern to High Gloss Step 2: 1000 Wet/Dry Sandpaper Step 3: 1200 Wet/Dry Sandpaper Step 4: AP1 Compound Paste Step 5: AP2 Compound Paste Step 6: Polishing Paste Step 7: Final Finish Liquid What Could Go Wrong? Removing a Scratch The Basics To Sand or to Fill Choosing the Level to Start Deep Scratches

3 Caution with Deep Scratches Light Scratches Sanding Check List Working with Special Polyester Lacquer Measuring the Hardener Mixing the Hardener Black (Ebony) White (Ivory) Clear Coat (Wood) Pouring Polyester Lacquer Is It Ready? What Could Go Wrong? Preparing the Repair Area Tools Removing the Damage Filling The Repair Applying Heat to the Fill, if necessary Leveling The Finish Special Scraper Metal Planer Leveling and Finish Tips When to Use Rex-Lith Gel Filler High Speed Buffing Recommended Professional Power Tools Buffing Wheels Setup Guidelines Cautions Before Using Method Guidelines Buffing Pads Setup Guidelines for Hand-held Polisher Setup Guidelines for Power Drill/Driver Cautions Before Using Method Guidelines

4 Addendum: Complex Repairs and Additional Information Building Dams Repairing White and Ivory Polyester Traditional Thin Finish Custom Color Outside Contractor Preparing the Veneer in Clear Polyester Repairs Color Bleeding Color Shifting Veneer Repairs The Dark Halo Removing White Pockets Satin Polyester Finish Thin Finish Repair Preparation Application Spraying and Sanding Tips Remove and Strip Polyester Cold Crack Repair What is a Cold Crack? Cleaning the Crack Pre-Sanding Filling Clear Finishes Sanding the Repair Level Final Sanding Buffing Final Thoughts

5 Product and Tool Reference Guide Products in the manual are highlighted in Blue for easy reference ** Included in the Intermediate Black Kit (KO ) *** Included in the Advanced Complete Kit, plus Intermediate Black Kit (KO ) POLYESTER AND SUPPLIES Special Polyester Lacquer: 100 ml (KO ). Also in Pint (KO 641-PT), Quart (KO 641-QT) ** Hardener Paste: 10 grams (KO ). Also in 10 gr 5-Pack (KO ). ** Mixing Cups: 10 pack (KO ). ** Mixing Spatulas: 10 pack (KO ). ** White Polyester Kit: White Polyester w/ hardener, mixing cup & spatula - 30 ml (AP ). *** TOOLS Edge Planer: For cutting off damaged edges and leveling damaged areas (KO 165). *** French Curve Scraper: For smoothing and trimming (AP FC-Scraper). ** Metal Planer: For quick surface removal of filling material (KO 163). ** Special Scraper: Unique hollow ground tool with four cutting edges (KO 406). ** ACCESSORIES Cloth, Ultra-Soft: Highly absorbent, lint free, scratch-free and tear-proof - 10 pack (KO ). ** Cork Sanding Block: For sanding and for use with the Felt Pad, easier handling (KO 418). ** Dam Sheets: Plastic dam-building sheets, vertical surface repairs - 5 pack (KO 641-Dam). ** Felt Pad: Use with sandpaper strips -or- cloth to apply compound and polish (KO 419). ** Pipette: Dropper included with every Repair Color (AP 295). ** Plastic Film: Clear foil used to mix colors over a surface. 5 pack (KO ). *** 5 52

6 REPAIR COLORS Polyester Intensive Black: Concentrated dye to blend with polyester - 30 ml (KO ). ** Asian Black Pigment: To adjust color for Asian black finishes - 30 ml bottle (KO 240-Asian). ** Medium Walnut Dye: 30 ml bottle (KO 220-IND-110). *** Light Mahogany Dye: 30 ml bottle (KO 220-IND-113). *** Touch-Up Paint Box: 12 Colors w/ Plastic Film, Cellulose Thinner & Pipette (KO 250-Box). *** Cellulose Thinner: Thins Dyes & Pigments. Dissolves Paint Box chips. Cleans Tools. (KO 710) Touch-Up Dye Graining Pen: Black (KO 205-IND-10). Also available in different colors. *** Color Edge Pen HG: For coloring high gloss edges and corners (KO 241-IND-#) ow-white SANDPAPER AND LUBRICANT 600 Wet/Dry Sandpaper: h Grade - 5 1/2" x 8 1/2" (AP SP-3M-Wet/Dry-600). ** 1000 Wet/Dry Sandpaper - 5 1/2" x 8 1/2" (AP SP-3M-Wet/Dry-1000). ** 1200 Wet/Dry Sandpaper - 5 1/2" x 8 1/2" (AP SP-3M-Wet/Dry-1200). ** 1500 Wet/Dry Sandpaper High Grade - 5 1/2" x 8 1/2" (AP SP-3M-Wet/Dry-1500) Wet/Dry Sandpaper - 5 1/2" x 8 1/2" (AP SP-3M-Wet/Dry-2000). Sanding Lubricant: Used to keep surface cool & lubricated ml bottle (KO ). ** COMPOUNDS AND POLISHES AP1 Compound: Menzerna Intensive Polish - Medium Grit - 4 oz. can (AP MZ-Paste-AP1). ** Available in 1-pint tub (AP MZ-Paste-2L). AP2 Compound: Menzerna Final Finish - Fine Grit - 4 oz. can (AP MZ-Paste-AP2). ** Available in 1-pint tub (AP MZ-Paste-P16). Polishing Paste: Konig Polyester Polish ml bottle (KO ). ** Available in 250 ml bottle (KO ). Final Finish Liquid: Menzerna high-gloss polish - 6 oz. bottle (AP MZ-Liquid ). ** Available in quart bottle (AP MZ-Liquid ). 6 52

7 REX-LITH GEL FILLER (Used to form new corners and fill in deep gouges) Transparent Filler Kit: Includes 100 ml Rex-Lith Gel Filler, 10 grams Hardener Paste, ** Blending Spatula, Plastic Film and Tube Roller (KO 151). Also available in Duo Wood/White Wood White Black (KO 155) ACRYLIC ENAMEL TOPCOAT (For Thin Finish Repair) High Gloss Black and White: Available in oz. including Hardener and Reducer Preval Spray System: Professional Airless Sprayer with power unit and reusable 6 oz. glass jar. POWER TOOLS AND ACCESSORIES (High Speed Buffing) Polisher, Wheels and Pads: For High Speed Buffing get perfect results using a high quality DeWalt Polisher Assorted Cotton and Canton Flannel Buffing Wheels, Loose and Sewn 3M Polishing and Compound Pads 3M Superbuff Pads. Drill and Polishing Set: For smaller areas, bring the advantages of a high quality Metabo drill. 3M pro quality variable speed drill. Check the catalog or online at AlliedPiano.com for more information. ADDITIONAL TOOLS AND SUPPLIES In addition to standard technician tools (e.g. screwdrivers, scissors), have the following: Acetone: For testing type of finish and cleaning tools. Gloves: Disposable. Industrial or medical grade to withstand resins and caustic products. Glue Hair Dryer: Small portable hair dryer with a low heat setting. Light: Used to inspect damaged area before, during and after a repair. Liner: Floor protection and cleanup. Small trash bag; drop cloth. Poly Bags: Resealable (e.g. Ziploc ). For storing cloths for each polish and compound. Rotary Tool: Dremel with Grinding Stones. Tape -edged tools. Towels/Rags: Work area over liner/trash bag. Thin absorbent cotton for drips, spills and cleanup. Tub: Plastic container for pre-warming polyester lacquer and pre-soaking wet/dry sandpaper. 7 52

8 Preparing the Damage Site QUICK REPAIR GUIDE Black Finishes 1. Clean out all damage with a French Curve Scraper or Rotary Tool with grinding stone and create a smooth 'duck pond' with no 'bumps' or 'steps' in the cut-out. Continue to Step 4. Clear Coat (Wood) Finishes 1. Clean out all damage with a French Curve Scraper or Rotary Tool with grinding stone and create a smooth 'duck pond' with no 'bumps' or 'steps' in the cut-out. 2. If veneer is damaged, repair with Rex-Lith filler and level to height of veneer. 3. Color veneer and seal with thin coat of mixed Polyester and Hardener glue. Wait 10 minutes. The Following Applies to All Finishes 4. Mix Polyester with Hardener and Dye/Pigment (if required), and pour into repair site. 5. Allow to cure for 30 minutes. 6. Wash top layer of wax off with acetone, or scrape off with the Special Scraper. 7. Level repair with wet 600 Wet/Dry Sandpaper using Sanding Lubricant and a Felt Pad until the site is level and no shiny halo is visible. 8. Sand at a right angle to the 600 scratches with wet 1000 Wet/Dry Sandpaper using Sanding Lubricant and a Felt Pad until all 600 grit scratches are gone. 9. Sand at a right angle to the 1000 scratches with wet 1200 Wet/Dry Sandpaper using Sanding Lubricant and a Felt Pad until all 1000 grit scratches are gone. 10. With a Polishing Cloth and a Felt Pad rub at a right angle to the 1200 scratches with AP1 Compound until all 1200 grit scratches are gone. 11. With a Polishing Cloth and a Felt Pad rub at a right angle to the AP1 scratches with AP2 Compound until all AP1 scratches are gone. 12. With a Polishing Cloth rub at a right angle to the AP2 scratches with Polishing Paste until all AP2 scratches are gone. 13. With a Polishing Cloth finish repair using Final Finish Liquid. Buff off. Mixing Polyester Lacquer 1. Pour amount needed into the Mixing Cup, up to line in the cup (1/4 oz., 7.5 ml). 2. With cap loosened, knead Hardener tube to mix contents. 3. Add a bead of hardener the size of a small green pea with a Mixing Spatula. 4. Ready to use for clear coat finishes. 5. For Black finishes, add up to 6 drops using a Pipette of Intensive Black color. If using a 2 nd black (e.g. Asian Black Pigment) to alter Intensive Black, use 2-4 drops of each black. Add extra hardener to compensate, about half of what is applied in step 3. NOTE: For White finishes, go to Repairing White and Ivory Polyester under the Addendum. Refer to the Complete Manual for Notes, Warnings and Explanations of these Procedures 8 52

9 INTRODUCTION This manual is written primarily referencing piano finishes. The same principles apply for the repair - Is It carefully before attempting any repairs for pianos or furniture. The König repair kits and methods make polyester repair much simpler than in days past. Systematic approach to polyester repair -- step by step with enough information so that you really understand what is going on. Fast curing time minute initial cure time means you can complete a repair in one visit. Easy measure -- Mix hardener and color system. Long shelf life -- 9 months is guaranteed, 12 months typical. Even longer if refrigerated with long delays between repairs. Highest quality materials -- used by piano and furniture manufacturers throughout the world. One-visit repairs with our procedures. Polyester repair -- like any other craft -- can approach art if we approach the job with care and attention to detail, and we have the right tools to do the job. König has provided you with the method and the materials. Even if you have some experience with polyester repair, we encourage you to spend the time to go through this manual. You will get the most out of our products by knowing the most about them. Technicians looking for specific information such as mixing ratios and special considerations for this type of polyester will want to reference this manual to learn how the König products work. Health precautions should be taken when using these or any refinishing materials. We strongly recommend the use of a quality charcoal filter mask, as well as disposable gloves. If you get polyester on your skin, it can be removed with acetone. Wash with soap and water after using acetone. König polyester repair products are for professional use only. Keep these and all chemicals out of the reach of children, and store in a cool place, away from living areas. WARNING: Only use a dedicated shop refrigerator to store Polyester Lacquer, Rex-Lith, glue and other caustic products. Do not use one that is now or will ever be used for food storage. Make sure to remove from refrigerator before a repair, returning to room temperature. 9 52

10 OVERVIEW The goal of any repair is to be undetectable. In polyester repair, there are a few basic requirements to be met if that is going to happen. Prep: For fills, there must be a clean and thorough preparation of the damage site. Flatness: The plane of the finish must be maintained so that the reflections that bounce off the surface remain true. Sheen: The surface must be free of any kind of scratch pattern. Color: Veneer color in the case of clear wood finishes, or colored polyester in the case of black, white or ivory, must be accurately matched. This sounds simple, but to accomplish all of them, you need to approach each repair systematically. This manual gives you such a system that will take the guess work and unpredictability out of repairing polyester finishes. Below is a convenient chart of the damage type and corresponding repair process. If you are repairing a chip, gouge, or very deep scratch, you will learn how to clean out the damage site, prepare it for the polyester lacquer, sand it flat again after the polyester has hardened, and finally, using finer and finer sandpapers along with compounds and polish, restore to a high gloss. If you are repairing a normal scratch or scuff mark which does not need added polyester or color, you will just use the proper sandpaper, compounds and polish to restore to a high gloss

11 ASSESSING THE SITUATION Is It Really Polyester? Before you pick up a tool, estimate a job, or even agree to do the job, you need to establish one important fact: Make sure that you are dealing with polyester! Polyester, polyurethane, and high gloss lacquer can all be made to give you that high gloss look. If you assume that the finish is polyester, and it turns out to be polyurethane, you'll have some differences. If it is nitrocellulose (lacquer), you will quickly be in trouble treating it as polyester. Acetone Test: Test the finish with a clean Polishing Cloth and Acetone, at the repair site or in an inconspicuous location (e.g. under the lid overhang), to know for sure. Pour a small amount of acetone onto a folded cloth and wipe the surface. So here's how to figure out what finish you are working with: Testing on Black and White Finishes: Colored polyester is very hard. Clean the surface of dust/dirt prior to testing. When you use the acetone test, the cloth will remain clean. Acetone will have no effect on this finish. Colored polyurethane has the same shine as polyester, but it is slightly softer, and is more easily scratched. When you do the acetone test, the cloth may or may not pick up some colored finish. Colored lacquer can be almost as mirror-like as polyester, but it is softer still. When you do the acetone test, the colored lacquer will soften or dissolve. If you suspect it is lacquer or are not sure of the finish, it is especially important to test in an inconspicuous location. If you have ruled out lacquer but are still not sure about polyurethane, try this: Take a small piece of 1000 grit sandpaper, and using a sanding block, sand a tiny area. Polyester sanding dust on the sandpaper will be very white, while polyurethane dust will be grey. Testing on Clear Coat Wood Finishes: Acetone will have no effect on clear polyester finishes. Clear polyurethane has less clarity. Visual inspection is most important for this finish because there is no colored lacquer that will show with the acetone test. Clear lacquer rarely appears as shiny as polyester. Acetone will melt the finish. If you suspect it is lacquer or are not sure of the finish, it is especially important to test in an inconspicuous location. WARNING: Some manufacturers mix finishes within a product. Some pianos have lacquer legs, polyester lids, and polyurethane rails. To make things even more interesting, some use a thick soft laminate or plastic for keyblocks, music shelf, and keybed facings

12 If you discover that the finish is polyurethane, and it requires the removal of only light scratches, it should be fairly safe to do so, provided that you tread lightly. Because it is softer than polyester, scratches will come out with a less severe level of abrasive than would be needed with polyester. In order to stay safe, stay away from anything stronger (more abrasive) than 1500 grit sandpaper, and stay away from the edges and corners. The finish tends to be thin in these areas. This is true for all finishes. If you are dealing with high gloss lacquer, you may already know how to get good results. If you can find a lacquer that is the right sheen or color, you can re-spray and feather the repair site into the rest of the finish. König Premium Aerosols are excellent products for topcoat repairs along with König Touch-Up products for veneer and case damage. Lacquer techniques are beyond the mandate of this manual, so for more information, check the catalog, online at AlliedPiano.com or contact us directly. OK -- Now that you know that you are dealing with polyester, we will look at the polishing process in detail

13 POLISHING AND SANDING EXERCISE FOR BEGINNERS Getting to Know What Each Step Looks Like In this section you will Polish Backwards from a high gloss to a 600 grit sanding pattern and then reverse steps to return to a high gloss finish. This will help you see what adjustments you may need to make to your technique, as well as teach you what each step in the process is supposed to look like. As you complete each step, try to remember what the finish looks like at each level. Start with a high gloss black polyester practice board that is free of scratches. If the practice board is perfect, start with Step 6. If the practice board has finger prints or is dirty, start with Step 7. It is important how you apply and rub product in every step, except for the Final Finish Liquid (circular motion). Whether it is polish, compound or sandpaper, the trick is the same... For this exercise, and in most instances, go back and forth in one direction at a time only! As you go back and forth, make tight "W's" side to side -- this helps avoid an uneven finish. Clean off the repair site completely between steps. Change the direction you rub in by 90 degrees whenever you change steps so that the lines you are creating are perpendicular to the lines you are working on. Keep both the pressure and the coverage even. Step 7: Final Finish Liquid With a Polishing Cloth folded to make a pad. Apply some Final Finish Liquid on to the cloth and rub the area you will be using for practice. Rub in a circular motion using medium pressure. After less than a minute, turn the polishing cloth over or use a new polishing cloth, wipe and buff. The finish should be perfect, with a. Step 6: Polishing Paste With a Polishing Cloth folded to make a pad. Apply some Polishing Paste on to the cloth and rub the area. Use enough paste so that the cloth does not cling or stick to the finish. Rub in a straight motion using medium pressure. Just like with compound or sandpaper, even pressure and even coverage of the area are required if it is to work properly. When you have 'polished' the area for about a minute, wipe and buff the area with a clean cloth. NOTE: Use a separate polishing cloth for every polish and compound. Keep each type of used cloth in a marked reclosable and sealed poly bag (e.g. Ziploc ). This will prevent contamination and allows you to do more repairs between replacing each cloth

14 Step 5: AP2 Compound Paste Using a Polishing Cloth with a Felt Pad inside, scoop out a small amount of AP2 Compound, a fine grit rubbing compound paste. Use enough compound so that you can rub the area without bogging down. For this exercise, use a straight pattern. As the compound is rubbed into the finish, it will break down and loose its cutting power. Re-apply the AP2 compound as required so that the area you are working with is fully covered in white compound. When you feel that you have fully and evenly covered the area you are working with, clean off the finish with a clean cloth. At this point, no visible abrasions should be seen by the eye, but the finish should appear slightly duller in contrast to the surrounding area. What is important is that it should have an even sheen. If you notice small scratches in the finish, you have either picked up dirt or dust, or you might be rubbing too hard. Try removing by reapplying compound. NOTE: It is very important to keep the tins of compound free from dirt. Make a practice of keeping the lids of the compounds closed except when you are working with them. If your compounds become contaminated with dirt or sanding residue, they will scratch the finish. Step 4: AP1 Compound Paste Using a Polishing Cloth with a Felt Pad inside, scoop out a small amount of AP1 Compound, a medium grit rubbing compound paste. Rub finish in the opposite direction of the previous step. As in Step 5, the compound will break down and loose its cutting power as you work. Re-apply the AP1 compound as required so that the area you are working with is fully covered in beige compound. When you feel that you have fully and evenly covered the area you are working with, clean off the finish with a clean cloth. At this point, the finish should appear evenly cloudy. Remember what the scratch pattern looks like before proceeding. In order to continue with this exercise onto the sanding portion, you will need to clean the piece with Sanding Lubricant to remove any trace of grease from the compounds. WARNING: Before starting to sand the base on which it is applied. This base is a flat sheen. Once you have reached it, no amount of buffing will make it any brighter. In fact, the more you buff, the more base coat you expose, because buffing removes the finish even more. Usually, the only way to recover from this situation is to re-spray the entire piece. We have High-Gloss Acrylic Topcoat for this situation, which may get you out of a jam. See the section Thin Finish Repair under the Addendum for more information. NOTE: Use a separate polishing cloth for every polish and compound. Keep each type of used cloth in a marked reclosable and sealed poly bag (e.g. Ziploc ). This will prevent contamination and allows you to do more repairs between replacing each cloth

15 Sandpaper and Lubricants Cut the paper into strips that are at least 1 / 2" narrower than the length of the Felt Pad and/or Cork Block. Use scissors to cut the paper instead of tearing it -- the ragged torn edges could fold over causing deep scratches as you sand. Cut the paper to size for the area being sanded. Use the smallest needed, to avoid spreading the repair area. Pre-wet the strips of sandpaper in warm water or Sanding Lubricant for a few minutes. This will soften the backing. Keep the surface wet as well as the paper. Use Sanding Lubricant to keep surface cool, and sand with an even, medium pressure. Sand only with a straight, back and forth motion in one direction. Watch out for dirt particles getting caught between the sandpaper and the finish. Clean often, by using a clean cloth and wiping in the same direction as you are sanding to avoid dragging sanding debris across. Very important #1: Change directions between each step. This enables you to find any remaining scratches from the previous step that have not been completely removed. Look closely, with good lighting, before moving forward. Very important #2: Wipe off the sanding dust regularly so you can see where you are. Use a different cloth for each grit. Wipe only in the direction of your current sanding. Wipe once with your cloth, then squirt on Sanding Lubricant and wipe again in the same direction. Repeat. At that point you will have a clean surface to inspect. Water is also a suitable lubricant, although it does not have the silkiness you get from Sanding Lubricant. Whichever you use, squirt or spray the liquid onto the surface before each sanding step. Using a quick blast from a hair dryer speeds up the drying time of your lubricant immensely, especially if using water. NOTE: Pre-soaking Sandpaper Strips: Wetting strips prior to sanding is important to soften the backing, preventing cracking. In the video, we show using individual plastic tubs for pre-soaking each grit of sandpaper. This is fine in the shop, but inconvenient in a home. For field work, presoak the strips ahead of time, and store each grit in a separate reclosable bag. They will stay soft. Step 3: 1200 Wet/Dry Sandpaper Sand down the finish at a right angle to the previous step with 1200 Wet/Dry Sandpaper using a Felt Pad and Sanding Lubricant. To inspect the finish, wipe the area clean and allow to dry. You have successfully covered the area if you see an even, light gray matte finish. Color is important, because if there are different shades of gray, or white streaks in the area, it means that there are some parts of the area that are rougher and more deeply scratched than others. Remember the whiter the finish, the deeper the scratch. It is very important to achieve an even color. Continue sanding until this has been achieved. Fine sandpaper, especially 1200, will 'load up' with polyester dust very easily if the surface becomes dry. If the paper loads (the grit becomes clogged), it will usually scratch the finish quite deeply. To avoid this, keep the area wet with Sanding Lubricant, and change the sandpaper often. Wipe the area clean and dry and remember what the scratch pattern looks like before proceeding

16 Step 2: 1000 Wet/Dry Sandpaper Sand down the finish at a right angle to the previous step with 1000 Wet/Dry Sandpaper using Sanding Lubricant and a Felt Pad. By sanding in the opposite direction of the scratch pattern left by the previous step, you will more easily see the 1000 grit scratch pattern without being confused by the underlying previous scratches. Remember to make a mental note, when you are done, of the type of finish the 1000 grit paper creates. Even coverage and color of the now whiter scratch pattern is always important. Wipe the area clean and dry and remember what the scratch pattern looks like before proceeding. Step 1: 600 Wet/Dry Sandpaper Sand down the finish at a right angle to the previous step with 600 Wet/Dry Sandpaper using Sanding Lubricant and a Felt Pad and/or Cork Block. The 600 grit has the ability to cut through polyester very quickly, so that using the firmer Cork Block is a better choice for even sanding. Using the same sanding techniques already learned, sand the area (in the opposite direction), and then inspect it. You will see that this pattern is quite white when clean and dry. With 600 grit paper it is still very important to have an even color of white, since the bright white lines in this scratch pattern are extra deep scratches. You can now proceed to the next chapter, Polishing Technique, to restore the original brilliant, glossy finish

17 SANDING AND POLISHING TECHNIQUE Repair Area Setup Protect the area on top of lids or the floor underneath for side repairs. Lay down a plastic liner, a small sturdy trash bag which can be used following the repair to discard trash. On top of the liner, lay down a thin absorbent cotton towel or rag for the work area and to catch any drips or spills. Make sure it is not too thick so products and tools do not tip over. Warning: Always discard polyester repair waste outside in a covered trash bin... Never inside, especially a home. NOTE: If you already have experience sanding and polishing polyester and bypassed the Polishing Exercise for Beginners. Please go back and read the Sandpaper and Lubricants box along with additional Warnings and Notes (saves not repeating under this section). From a 600 Grit Scratch Pattern to High Gloss Later in this manual, Leveling the Finish, you will learn how to sand out scratches and level hardened polyester fills. In each case you will end up with a surface that has been sanded evenly with 600 grit paper, which is Step 1 in the Polishing Technique. It is from that point that we will start. Step 2: 1000 Wet/Dry Sandpaper Make sure that the entire area is clean and dry. Wrap a pre-moistened strip of 1000 Wet/Dry Sandpaper around the Felt Pad and sand in a straight, back-and-forth motion perpendicular to the scratch pattern made by the 600 grit sandpaper. As you sand, lubricate with Sanding Lubricant. You need to sand an area larger than the 600 grit pattern, so that you can be sure that you get all the scratches around the outside. But keep an eye on it -- it is easy to have a small repair become a huge repair by overlapping too much on each level. Inspect the area by wiping completely clean and dry. You have completed this level when no white lines running perpendicular to the direction of the 1000 grit scratches can be detected anywhere in the pattern. This is why you always change directions when you change grits of sandpaper. Look very closely on several different angles -- especially around the edges. If you miss part of the 600 grit pattern, you will have to come back to this level to get it out. If you are confident that you have removed all the scratches from the 600 grit pattern with the 1000 grit sandpaper, wipe the area completely clean and dry and proceed to the next step. NOTE: The Cork Block and Felt Pad as a harder block might. The felt especially is pliable and designed specifically for polyester and touch-up repair. The cork block is recommended for the 600 grit sanding and the felt pad for the finer grits. Some may find using a cork block with a felt pad underneath easier to handle, Cork Block with Felt Pad (KO ) - or - glue a felt pad to the bottom of a cork block

18 Step 3: 1200 Wet/Dry Sandpaper Use the same routine as you did in the last step. Make sure that the entire area is clean and dry. Wrap a pre-moistened strip of 1200 Wet/Dry Sandpaper around the Felt Pad and sand in a straight, back and forth motion perpendicular to the scratch pattern of the 1000 grit. Lubricate with Sanding Lubricant. Overlap the perimeter of the 1000 grit scratch pattern to ensure coverage. Inspect the area by wiping completely clean and dry. You have completed this level when no white lines running perpendicular to the direction of the 1200 scratches can be detected anywhere in the pattern. If you are confident that you have removed all the scratches from the 1000 grit pattern, use Liquid Sandpaper to wipe the area completely clean and dry before proceeding to the next step. Step 4: AP1 Compound Paste Using a Polishing Cloth with a Felt Pad inside, scoop out a small amount of AP1 Compound, a medium grit rubbing compound paste. Using a back-and-forth 'tight W' motion, in the opposite direction of the existing scratch pattern, rub the compound evenly over the area. The compound may break down and loose its cutting power. If needed, reapply so that the area you are working with is fully covered in beige compound. Remember to cover an area slightly larger than the 1200 grit scratch pattern, and remember that the compound needs to be applied with the same control and coverage as sandpaper does. Avoid a rubbing style that will produce heat. Firm but not excessive pressure is desired and should be reduced as you near the end of the process. Clean the area and inspect the scratch pattern. If the 1200 grit scratch pattern is still visible, continue rubbing. The area, when complete, should appear cloudy with no visible lines of any kind running perpendicular to the direction you are rubbing. Clean the area before proceeding. Step 5: AP2 Compound Paste Using a Polishing Cloth with a Felt Pad inside, scoop out a small amount of AP2 Compound, a fine grit rubbing compound paste. Repeat the procedure in Step 4. Rub in the opposite direction of the previous step. This level is complete when the entire area is clear but a bit dull, and there are no lines visible in any direction. NOTE: It is very important to keep the tins of compound free from dirt. Make a practice of keeping the lids of the compounds closed except when you are working with them. If your compounds become contaminated with dirt or sanding residue, they will scratch the finish. Step 6: Polishing Paste With a Polishing Cloth folded to make a pad, apply some Polishing Paste onto the cloth and rub it in. Use enough paste so that the cloth does not cling or stick to the finish. Rub in a straight motion using medium pressure. Just like with compound or sandpaper, even pressure and even coverage of the area are required if it is to work properly. When you have polished the area for about a minute, 18 52

19 wipe and buff the area with a clean cloth. If there are visible abrasions, it means that either dirt got caught in your cloth, or you were rubbing too hard. Change your style, reapply polish, and try to get rid of the cloudiness or abrasions. Step 7: Final Finish Liquid If all has gone well, the repair area will be quite close to a high gloss. With a Polishing Cloth folded to make a pad. Apply some Final Finish Liquid on to the cloth and rub in a circular motion using medium pressure. After less than a minute, turn the polishing cloth over or use a new WARNING: When polyester is polished for a while, it tends to get warm, and softer. As a result, things that wouldn't scratch a cold finish will scratch a warm one. Use care after each step, so that you don't introduce scratches just by cleaning. What Could Go Wrong? Very often the first couple of tries end with a repair area that is shiny, but with score lines that can be seen in the shine. Use a light after each step to inspect the repair area, even in an area that appears well lit. Light reflects differently from different angles, so check from all directions. look at the most common reasons for it: In one of the sanding levels, insufficient polyester was removed to get to the bottom of the scratch pattern. The sandpaper was used beyond its usefulness and small pieces of polyester became lodged in the grit causing it to make deep scratches. The area was not completely cleaned between levels. The sandpaper had ragged edges that folded under to cause gouging. The rubbing compounds are contaminated with dirt or grit. Solution: Treat the score lines like just another scratch that has to be sanded out. You may choose to go back to 1000 grit paper, 1200 grit, or one of the compounds. If you do go back to sanding, remember to wash the area with Liquid Sandpaper to remove any grease left from the compounds prior to sanding. Wherever you start, you will need to proceed through each remaining step until you get back to Step 7. When you feel confident with these procedures, continue on. Otherwise, take a break, and try it again. The materials and the technique when used together correctly will produce factory quality results -- you just need to get a feel for it

20 The Basics REMOVING A SCRATCH Here are the basic decisions you will have to make when you approach a scratch that needs to be repaired: Is this scratch safe to sand out, or do you need to open it up and fill it with polyester? If it can be sanded out, what grit of sandpaper (or rubbing compound) are you going to start with? To Sand or to Fill With most repairs, you won't need to think much about whether to sand or to fill, but deep scratches can be a bit of a coin toss. Experience is the only teacher when deciding whether a deep scratch can be sanded out, or whether it has to be filled with polyester first. If a scratch can be sanded down to its lowest point and then the area is brought back up to a high polish, it will produce the most invisible repair. However, if the polyester finish is not thick enough, you run the risk of sanding through the finish to the wood. Even if there is sufficient polyester, careful sanding is required to avoid causing a noticeable 'dip' in the finish when sanding out a deep scratch. If you think that the scratch is too deep, your alternative is to shave down the area, prepare it as described below, and fill with polyester. Polyester repair technicians are at the mercy of the factory when making this decision. There is no practical way to tell how thick the finish is at any point in a cabinet piece. Edges frequently are much thinner than the rest of the piece. Our König High Gloss Color Edge Pens (KO 241 HG) do a nice job on edges, but it's nicer if you can leave the edges intact. Knowing the manufacturer does not mean every piece from that company will be like the others. With global manufacturing, expecting change is prudent. This is a field call, supported by experience and caution. Read the following section on Deep Scratches for more help

21 Choosing the Level to Start Common sense plays a big part in polyester repair. If you are being asked to remove light scuff marks from a music desk, it is not necessary to start by sanding with 600 grit sandpaper. That would be like using a steamroller to stomp a mushroom. Conversely, trying to sand out a deep scratch with 1200 grit sandpaper would take hours. You need to find a level of abrasive that will get you to the bottom of the scratch in a reasonable time, without leaving a deeper scratch pattern than necessary. Whatever level you start with, make sure that your first sanding is across the scratch, so that you can see (when the surface is wiped clean and dried) if the original damage has been removed. Deep Scratches If you decide to sand out a deep scratch, you will be creating a 'low' spot in the finish. Low spots are not a big issue on small parts or vertical surfaces, but even a small 'dip' in the middle of a grand piano lid or a table top will be noticeable. The effect of this dip in the finish can be minimized, however, by increasing the size of the sanding area proportional to the depth of the scratch. The deeper the scratch, the larger the area sanded. This will make the dip so gradual that it won't be easily noticed. It will also mean that you have a larger area to sand and polish or buff. On the last page of this manual is a paragraph on meeting different answers for different situations. When sanding out scratches, don't forget the first commandment of polyester: Thou shall not sand without a sanding block. Even a couple of strokes with a bare hand or fingers will be enough to mess up the plane of the finish. Make sure that you have sanded the scratch completely out. No sign of the scratch (it will appear as a white line) should be visible after you have cleaned and dried the sanding area. If there is still a white line where the scratch was, you must continue to sand until it disappears. With really deep scratches, there is the threat of sanding right through the finish to the layer underneath. This is a bad thing. So here's a trick that will help you decide what to do on those really deep scratches. Caution with Deep Scratches It can be hard to know how deep a scratch is until you start sanding. You can try 600 grit sandpaper as a test, to learn what it will take in sanding to get to the bottom of the scratch. If it seems that aggressive sanding will be needed, here is a method to help you decide which path to take. 1. Take a scraper, such as a narrow chisel with ground-down points, and shave along the scratch just like you would if you were going to fill it, but watch carefully as you remove the polyester. König also has a new tool for this, called the Edge Planer

22 2. You should be able to tell when you have reached the bottom of the scratch. When you do, stop and take a look at the depth of the trough you just made. Now you have a realistic picture of how deep you would have to sand if you chose to go ahead and sand out the scratch. 3. If you decide that there is enough finish to do so, you can start sanding. Remember, the deeper the scratch, the wider the sanding area so that you minimize the dip in the finish. 4. If, however, you think that too much polyester would have to be removed, you are all set for filling the scratch site with polyester. Light Scratches If the scratch is not too deep, hard to feel with the fingernail, you can start at a higher (finer) level of sanding than you would for a deep scratch. As you learned with deeper scratches, your job is to sand the finish down until you have reached the bottom of the scratch -- so that you cannot see any sign of the scratch in your dried sanding pattern. It is good practice to start with a level finer than you think will be required. It doesn't hurt, and you could save yourself some time. NOTE: If the first grit you use on an untouched shiny finish is 1200, it is quite common for the sandpaper to load up almost instantly. Gone unchecked, this will cause the sandpaper to leave deep score lines in the finish. Degreasing the finish before sanding, and changing the sandpaper frequently will reduce this risk. Sanding Check List Remember that when you start sanding the scratch, no matter what level you start with, it is critical to sand perpendicular to (across) the scratch. This will allow you to see the original scratch within the white scratch pattern made by the sandpaper. Here are the other things to keep in mind as you approach a scratch: 1. Cut the sandpaper in strips at least 1 / 2" narrower than the width of the sanding block or pad. 2. Pre-moisten the sandpaper, and use Sanding Lubricant during sanding. 3. Always sand in only one direction per grit of sandpaper, using the back-and-forth 'W' pattern you have already learned. 4. Periodically dry off the area and inspect the scratch pattern. When you can no longer see the white line of the original scratch in the new scratch pattern, you are done. However, you might want to continue sanding with a light pressure around the edges of the sanding pattern, just to 'feather' the edges of the pattern out. If there are 'tire treads' in the finish, you will feel them as your block passes over them they will cause the block to hesitate. 5. Clean the entire surface really carefully before going on to the next level of abrasive. Continue on until you are looking at polyester perfection! Once you are experienced at examining the results of your sanding, you might experiment with sanding all steps in the same direction. This will minimize the size of the repair area, but always remember that the only way to positively know that each step has been completed is to study the piece carefully, from all angles, with good lighting, for cross-hatching (previous step not completely eliminated.) 22 52

23 WORKING WITH SPECIAL POLYESTER LACQUER Pre-warming Polyester Lacquer Heat the polyester to no more than 85 degrees F, with the can somewhat warm to the touch. Holding it under hot tap water is simplest. Or, heat some water in a plastic container in the microwave. Make it quite warm, but not boiling. Too high a temperature destroys the polyester. If it is too cold, about 65 F., it will not set up. A hair dryer will also work. Next, shake the warmed container thoroughly. This blends in the wax which is part of the formula, and it needs to be evenly distributed within the can before you pour it off. The liquid will become thinner. This will help in 3 ways: 1. Bubbles will dissipate quicker due to lower viscosity. 2. The wax will be evenly distributed. 3. The mixture will harden faster. Always Shake Polyester Before Using ery important to shake the polyester tube or can before using, with lid securely in place. The contents, including wax, separate when stored cool as recommended for shelf life The goal is to have a mixture of polyester that is: Fully mixed -- no white hardener floating around. Free of air bubbles. Going to gel in about 2-3 minutes. Going to be fully hard in under 60 minutes. Measuring the Hardener 1. In a Mixing Cup, pour Polyester Lacquer up to the line near the bottom, which is 1/4 oz. (7.5 ml.). 2. With the cap slightly loose, knead the Hardener tube to thoroughly mix its contents. 3. Add a small pea amount of Hardener for Clear repairs and mix thoroughly. For coloring, add Color and Hardener and mix thoroughly

24 WARNING: Always add and mix hardener into the polyester before you add any color. We recommend hardener first, so you can be sure you have it fully blended in. Just the color or dropper. If you are experimenting with getting the perfect color, do that separately in a batch of polyester without hardener. Then, duplicate your procedure as above. Mixing the Hardener Mixing the hardener into the polyester without creating bubbles is easy: 1. Leave the bead of hardener on the inside of the cup away from the polyester or on the mixing spatula. 2. Pick up some polyester with the Mixing Spatula, and mix it with the hardener to make a concentrated mixture. 3. Add this concentrate to the rest of the polyester in the mixing cup and stir slowly until the polyester has returned to a clear liquid with nothing floating around. WARNING: If you add too much hardener, the mixture will overheat as it gels, and clear polyester will turn dark amber. In addition, a strong chemical smell will be apparent. When this situation arises, immediately fill the cup with cold water to cool it down. Avoid breathing these fumes if you possibly can. Do not use this mixture for a repair, as it will probably deform in the repair site. Black (Ebony) To make the polyester black, use the Intensive Black Dye. This dye can be mixed up to 10% by volume without affecting the polyester. Make sure that the dye is completely mixed into the polyester before applying the polyester to the repair. Typical application for a 1/4 oz. (7.5 ml.) of polyester in a mixing cup is 6 drops using the transfer Pipette

25 If you are working on Asian products, you will need to use the Asian Black Pigment. This pigment must be mixed in along with the Intensive Black Dye to make the polyester less blue. A typical application for a 1/4 oz. of polyester in a mixing cup is 3 drops of Intensive Black and 3 drops of Asian Black. Add a drop of dye or pigment to increase the intensity (dye) or tone down the color (pigment, greyer and less blue) to match the repair area. WARNING: If you use pigment, you must shake it very well to ensure that the color is thoroughly blended. By holding the cup over a light source, you can easily see if the color has properly mixed, or is still streaked. White (Ivory) The White Polyester Kit is a pre-mixed pure white polyester lacquer. It comes with the Advanced Complete Kit or can be purchased separately. Shades of white will require the Paint Box to create the correct color. When using the Mixing Cup for small repairs, filling white polyester to the line is 1/4 oz. (7.5 ml.). If unsure of the correct colors to create a shade of white, experiment using only the Paint Box colors with the clear graduated mixing cup or Plastic Film. To form new corners and fill in deep gouges, we recommend using Rex Lith White Gel Filler. Go to the section Repairing White and Ivory Polyester under the Addendum: Complex Repairs and Additional Information for methods of working with White and Ivory repairs. Clear Coat (Wood) For clear coat wood finishes, we recommend getting the Medium Walnut Dye and Light Mahogany Dye along with the Paint Box to adjust the color. The Paint Box is a convenient palette of 12 concentrated pigments bound in acrylic resin. To use the Paint Box, simply add a few drops of Cellulose Thinner to each of the colors you plan to use, wait a couple of minutes, and the paint will be liquefied and ready to use. Add the colors needed to the wood dyes for a correct match to the repair area. Go to the section Preparing the Veneer in Clear Polyester Repairs under the Addendum: Complex Repairs and Additional Information for a more complete explanation of working with clear coat repairs. NOTE: König offers a large assortment of colors in Dyes and Pigments, but a more practical solution is the Paint Box. For large projects or common jobs needing a specific color, see the catalog or online at

26 Pouring Polyester Lacquer You can either use the Mixing Spatula to transfer the polyester to the repair site. If the mixture should start to gel before you start to pour, you must discard the mixture and start again. By pouring polyester that has started to gel, you run the risk of air bubbles getting trapped beneath the surface, poor adhesion to the repair edge, and wrinkles. It is always faster to mix a new pot than to waste time on a doomed repair. Polyester Lacquer can be layered without sanding between coats. As long as the first layer is not more than one hour old (it's still sticky), and the waxy coating of the first layer has not been touched or been contaminated by dirt, a new mixture of polyester can be mixed up and poured right on top of it. Is it ready? After pouring your fill, set the mixing stick back in the cup and set them down together where they After twenty minutes or so, very gently t minutes and try again. By this time, the stick and mixture should come out clean, with a clean, hard surface on the bottom, and a waxy look on top. If it is sticky on the bottom, know that it is like that at the bottom of your repair fill, and just start over. Remove the fill, scrape it with the FC Scraper to remove the residue, and clean with acetone for insurance. The best place for the cup is outside, away from children and animal, minimizing the fumes in the home. But use your judgment if the weather outside is either too cold, or too humid, to give a fair test of the batch. It is very important to let the polyester harden without any disturbance. Ten minutes after it gels it can handle movement of the case part (e.g. Turning the part upside-down), but flexing the part (in the case of a lid) could destroy the repair. touch or work with it until at least 30 minutes after the material has jelled. Polyester lacquer forms a sticky film on the top as it hardens, due to the wax component rising to the top. You can remove this with acetone, or use your König scraper

27 What Could Go Wrong? In addition to improper mixing ratios, polyester lacquer may not harden for several reasons: The polyester had exceeded its shelf life, or was stored in a hot environment. Explanation: Polyester has a recommended shelf-life of 9-12 months. This resin does not normally thicken up like most other resins do, so it is easy to think that the polyester is OK to use even after 2 years. However, performance declines after the first year. Direct sunlight will also affect its performance. The shelf life is longest if both the resin and hardener are stored in a cool place. There is excessive humidity. Explanation: More hardener may be required, or a heat source used. Solution: Ten minutes after the polyester has had its initial set, heat the fill site with a hair dryer on the lowest setting to drive off the excessive humidity. Do not allow the surface to become so hot that it is uncomfortable to touch. You can also use a light bulb for this. Do NOT use moving air during the initial curing. The repair site was contaminated. Explanation: Polyester will not harden in the presence of some plastics or solvents. Solution: Do not use air-dry fillers, epoxy, or especially burn-in sticks in your veneer repairs. These will interfere with the polyester. If you need to use a filler, choose either one of our Rex-Lith line of fillers (available in transparent, black, white, wood, and duo wood/white). If pre-coloring a repair site, use dye rather than pigment, and be certain to seal it off prior to filling. -to. Too much color was used in the color matching of the veneer (clear repairs). Explanation: If you use too much color on the veneer, the layer of color may prevent the polyester from properly adhering to the veneer. This will cause the polyester to pull out of the repair, usually during the last stages of sanding. It's something that can fool you, because the top of the polyester is perfectly hard. If this happens, all you can do is start over again. Solution: Once you are happy with the veneer colors, mix up a small amount of polyester and hardener, and paint on a very thin layer of polyester over the repair floor but not up the walls. After 10 minutes, without disturbing the site, mix a new batch of polyester and fill the rest of the repair. This will 'lock in' the color, and prevent the colors from interfering with the polyester

28 PREPARING THE REPAIR AREA When a technician sprays lacquer on old lacquer, the new lacquer bonds with the old to form a joint-less transition between repair area and original finish. In polyester this does not happen. Old polyester cannot be dissolved by new polyester, and so we are challenged by the need to create a smooth physical joint between old and new. This is achieved by creating a smooth, fresh cut around all of the damage, and then shaving the walls to form a smooth, gradual bowl. Tools Our favorite tool for this part of the job is the French Curve Scraper (FC Scraper), which is included in the Complete Polyester Repair Kit. With multiple radii, you will find a curve that matches the size of the damage. Hold the FC Scraper at an angle away from you that allows you to see and control your work. Hold it with both hands with the cutting side leading. This tool does not have a sharp burr, but you will find which the cutting side is easily. It has just the right attributes to make quick work of the clean-up, without the aggressive cutting of other scrapers. It has a good amount of flex. Push the scraper forward, keeping the scraper steady and controlled. Once the interior looks good, move around the perimeter to smooth the edges and remove all the little chips and uneven appearance. Symmetrical repair sites are less noticeable, with no sharp cliffs along the edge, or uneven bottoms. Another handy tool is a Rotary Tool (e.g. Dremel) with a Grinding Stone attachment (we recommend #83322). Use it to grind the damage out of the repair site, leaving a smooth surface in and around the repair area

29 Removing the Damage Careful attention must be paid to the original damage to ensure that all of the damage is removed. Look at the reflection of the damage at a low angle to find out if the finish has lifted away from the wood. It gives the appearance of a wave in the finish if there is lifting that is too shallow to be seen or felt. If you still see this, just go a little further, until the entire area has one consistent appearance under a light. Only go as deep as required, keeping in mind that you need to make enough of a fill to allow for leveling and sanding without removing what you just added. And, be sure you have gotten to the bottom of the damage. It is not really more work to fill a slightly deeper hole. On the other hand, it is not fun to find that you did not reach the bottom. Any crack that remains under a fill will come back to haunt you by showing up at the very end, when you are polishing. Make sure that the bottom of the repair (the floor) is smooth and symmetrical, and that there are no hair-like wood fibers sticking up. These fibers will cause pin holes to appear after sanding. There should be no hills within the repair. The polyester walls of the repair need to be shaved smooth with the scraper so that there is a smooth slope that starts at the top of the finish and ends up at the floor of the repair. The more gradual this slope, the better. If you are able to eliminate a step between the polyester and the floor, you will greatly improve your chances of having an undetectable repair. Avoid tight curves, corners, and vertical chatter marks in this edge. The smoother this edge is, the more invisible the repair will be

30 FILLING THE REPAIR At this point, you can mix the Polyester Lacquer as described earlier. Use the Mixing Spatula to drop polyester into the center of the repair site, and let it flow out to the edges. If necessary, coax the polyester over the edge, being careful to avoid trapping air bubbles in the resin. Pour enough polyester into the repair so that a mound forms that is about.050" higher than the top of the finish, and that overlaps the repair all the way around by about 1/8". This compensates for the polyester that may be absorbed into the wood. On occasion, more polyester is absorbed into the wood than was expected. It will not shrink (unless overheated in buffing) but will find its way into porous spots that have not been removed or sealed. Polyester Lacquer, the top layer of the resin stays sticky even after the rest of the repair has completely hardened. This means that if you need to add more polyester you can do so as long as the resin has not been contaminated with dirt. As long as the first layer is still sticky on top, the second layer will chemically bond with the first. To remove this wax surface in preparation for sanding, simply wash it off with acetone, or scraper it off with the Special Scraper. Once the sticky layer has been removed, you can no longer add new polyester to the repair. Applying Heat to the Fill, if necessary This can be necessary for repairs where the standard room temperature is too cool (below 68 F.), or the humidity is very high. If the room is cold, use a hair dryer to warm the surface being repaired, as well as warming the fill afterwards. This is in addition to heating the polyester before mixing to around 85 F. If you wish to apply heat during the hardening process, you must wait at least 10 minutes after the polyester has gelled. At that point a hair dryer on the lowest setting can be placed about 6 inches away from the repair, not blowing directly on the repair but from the side. The finish should never be heated hot enough that it more than just comfortably warm to the touch

31 LEVELING THE FINISH After the repair has hardened and the sticky skin has been cleaned off, the next step is to make the repair site level to the finish. You can use your choice of planer, scraper, and chisel to level the polyester fill. Special Scraper This tool has much to recommend it and is included in the Complete Polyester Repair Kit. All four long edges are scrapers, so it will last a long time. It is quite flexible, so you can point the ends away from your fill. You can also mask the pointed ends of the scraper to avoid causing damage with it. You may want to mask those ends with three layers of tape, removing one at a time as you get close to level. Use care to keep the scraper level so that the corner of the blade doesn't dig into the surrounding finish. Start nearer the center of the repair and shave outwards. This will help avoid the risk of chipping or pulling out the fill. Metal Planer The Metal Planer is a two-sided (both sides the same) planer held by a magnet in its casing. It has an indent on the top side for your index finger, helping you keep the planer flat. To use, place the bla edge of the fill, to avoid lifting and popping out your repair. Carry a brush, such as an old toothbrush, to keep the planer cleaner. Have a small trash area handy for these sweepings and your spent sandpaper. Whichever tool you are using, mask off the surrounding area to avoid damaging it. WARNING: If the repair polyester is not hard enough, this procedure will cause the polyester to form what look like tiny broken bubbles. Do not continue until the polyester is hard enough to shave to a smooth surface