COLDWORKING. Part 2 - Without Machines

Transcription

1 COLDWORKING Part 2 - Without Machines

2 Contemporary Glass Society. All rights reserved. Published by Contemporary Glass Society (CGS). By reading and using this ebook you accept the Terms and Conditions of Use as set out in the Contemporary Glass Society at: This ebook is for your own private use. Please don t copy or share it. If you would like to reproduce or distribute this publication for educational purposes only, you will need written permission from CGS. Everything has been done to ensure that the content of this ebook is accurate at the time of publication but you will need to verify details - such as current prices & availability of items - for yourself. In creating and promoting these ebooks CGS aims to increase access to information. CGS cannot be held responsible for accuracy of information including approaches to safe working practice. All work undertaken in response to this publication is done at the risk of the individual. Follow health and safety best practice and always consult manufacturers guides for information on specific tools and materials. For more information, please contact: admin@cgs.org.uk Website: Facebook: Contemporary Glass Society Pinterest: pinterest.com/cgsglass 2

3 COLDWORKING Part 2 - Without Machines By Jacque Pavlosky Editor Milly Frances Photography Jacque Pavlosky Design & Typesetting April Stambaugh Cover image: Spiral Zigzag, Jacque Pavlosky, 2014 Header & footer image: Detail from Ripple Landscape, Kane Cali, 2011 Photography: Manipulated details taken from original photo by Ester Segarra 3

4 Contents Health and Safety 5 Keep it Clean 6 Methods and Tips 6 Hand Tools 7 Handlapping With Grits 8 and Other Methods Recommended Suppliers 11 4

5 Patience, focus and care are essential attributes for successful coldworking. More damage is done to glass during the coldworking process than at any other time. It s worth remembering that any coldworking you do on your piece will alter the surface of the area you are working. This in turn may affect what you need to do to the rest of the piece to tie it all together. Health and Safety 1 Essential safety equipment No discussion of coldworking would be complete without mentioning health and safety. At the very least you should equip yourself with the following: rubber or plastic apron, safety glasses, ear defenders, safety visor, sturdy waterproof gloves and a dust mask. The dust mask must have a filter specifically for use with fine airborne particles. Always refer to manufacturers instructions. 5

6 Keep it Clean An immaculate grit-free working area is crucial for fruitful coldworking. This means your glass, your working area surfaces, your tools, your apron and you! Think operating theatre! Remnants of previous grits contaminate and scratch, so: Rinse your glass, hand pads and work area frequently and always between different grades. If using a bowl, replace the water when changing to the next grade (running water is preferable if you have it). Keep hand towels grit free. If you dry your gritty hands on a towel, that grit will transfer to your hands next time you use the towel and from there onto your tools and glass. Remember that water must be used in conjunction with all coldworking tools and methods. This prevents health risk from fine glass dust particles from becoming airborne and prevents the abrasive surfaces of tools from becoming clogged. Methods and Tips Prepare a clean, cushioned surface on which to place your glass, such as polystyrene with kitchen roll or newspaper layered on top. Use dense foam padding in a washing up bowl to support glass whilst working or a clean wooden or rubber work surface. 2 Marking up the surface to be ground, and bevelling the edges with a hand pad 6

7 Do not put work finished side down. Protect vulnerable or finished sides with a layer or two of gaffer tape when working other surfaces. Before you start to work a surface, bevel the edges at a 45 angle, using the same grade diamond pad you are about to grind with.. This helps avoid sharp or jagged edges that may chip and scratch your glass. Do this between each grade. To be sure you have sufficiently cold worked for each grade of grit, diamond pad, or wet and dry silicon carbide sandpaper, first cover the surface with a crisscross pattern using permanent marker and let it dry. When you have ground off all the marks you will know you have covered the whole surface equally. This does not mean you are finished! Dry the glass and look for imperfections as they are not visible when the glass is wet. Mark up imperfections and regrind. Write on the glass the last grade you used in case you forget when leaving your work for a period of time. Hand Tools A cheap metal glass cutter with a ball end and notches or grozing pliers are useful for nibbling and tapping off flashing. 3 Hand tools and materials for coldworking 7

8 Diamond files come with different profiles for removing glass quickly. They are used in one direction only to avoid chipping. Diamond impregnated hand pads, sheets, and files are essential for bevelling, shaping and grinding. The most commonly used employ diamonds embedded into nickel, but are also available in a softer resin base. Both types are available in a variety of profiles and forms. The most commonly used grades for hand working are Green (60) roughest, Black (120), Red (200), and Yellow (400) finest. You can purchase higher grades all the way up to 12,000, but keep in mind that a highly polished surface is not always desirable or appropriate, and is extremely difficult to achieve using just hand tools. If you wish to attempt a finer finish, use higher grit pads, cork and pumice, followed by cerium and felt. But remember a high polish is really next to impossible without the aid of machinery. A surface up to R600 is very good and aesthetic compromise. Hand Lapping with Grits 4 Lapping using grit, water, and washing up liquid on a sheet of glass Lapping Flat Surfaces Silicone carbide (sharpest) or aluminium oxide (softer) are the two grits used for hand lapping. For achieving a flat surface it is best to start with a very rough grit (80-120) on a flat bed grinder if possible, then on through 220, 400, to 600, or similar. 8

9 It s good practice to use a specific sheet of window glass for each grade grit. Put a couple of sheets of damp newspaper between the window glass and the table to prevent it shifting during grinding. Put 1-2 tablespoons of grit in the centre of the window glass (at least 50 x 40cm), add enough water to make a loose slurry and allow the glass to slide easily (2 or more tablespoons), and add a couple drops of washing up liquid. This will help, especially with the finer grits ( ), to prevent suction between the glass and your work. A surface up to 600 is very good and aesthetic compromise. Bevel the edges of your glass before starting to avoid chipping and scratching. Use a diamond pad of the same grade as your grit each time before you start to grind. Grinding Shaped Surfaces Use the same marking up system used in the hand pad method. Lap in a figure of 8 or circular motion, turning the glass regularly in quarter turns every 20 laps or so to grind evenly until all the permanent marker marks are gone. For shaped surfaces reverse the flat lapping method by bringing hand held glass to your work which has been shaped and bevelled to conform to the profile of your work. Make up a thick slurry of grit, water, and a few drops of washing up liquid in a small bowl, apply it directly to your piece and grind with the hand held glass in circular movements, adding more grit as required. A piece of thin copper sheet or mesh, or scotchbrite pad with grit slurry are also effective for shaped surfaces. Wet and dry silicon carbide sandpaper in equivalent grades to grits is useful on its own, or can be used in conjunction with equivalent silicone carbide grits. Finally, a soft polish can be achieved using cork with pumice and felt. 9

10 5 Cleaning fluids to help remove stubborn marks and tape residue Finally, remove any remaining stubborn tape or marker residue with solvents such as acetone, metholated spirits, denatured alcohol, or lighter fluid. Then cork with pumice and finish off by felting with cerium. Plug yourself in to your ipod and with your favourite music and the job will go much faster and pleasantly! Always stop working if you are fatigued. Most accidents and breakages occur when you are too tired to concentrate effectively. 10

11 Recommended Suppliers UK DK Holdings Good for diamond tools and equipment. Garmur Abrasives Suppliers of silicone carbide and aluminium oxide grits USA His Glassworks (USA) Provides a full range of coldworking tools and equipment. Glass artist Jacque Pavlosky welcomes glass artists to share facilities in her kiln formed glass studio in rural Buckinghamshire. 11