Right On Replicas, LLC Step-by-Step Review * How to Build a Vacuform (vacuum-formed) Scale Model

Transcription

1 Right On Replicas, LLC Step-by-Step Review * How to Build a Vacuform (vacuum-formed) Scale Model Review and Photos by Doug Cole If you ve been building models for a while you ve probably heard the term vacuform kit. As opposed to the usual injection molded kits that are so common these days, the vacuum molded kit is formed when a heated sheet of plastic is lowered onto a relief die and the air is vacuumed out to pull the plastic onto the die plate. The plastic then cools and conforms to the die plate. The result is a single sheet model kit that looks like this. The parts have been outlined in marker here to show them clearly. Most people shy away from these kits as they clearly involve more work than just cutting the pieces off of the tree as you do with injection molded kits but there are some reasons why you might want to consider building one. First off it s really not that hard to turn that plastic sheet into a really nice looking model (like the Messerschmitt Bf 109-E above). And secondly, there are quite a few models marketed that way that the injection molders never made. Quite often odd or unusual models are found in the Vacuform offerings that the main stream model companies would never consider producing. While they used to be quite common the only good source for vacuform kits is online as most of the mainline hobby stores only deal with high volume kits. A search for vacuform kits at online auction site will turn up a large number of these kits and you might just find one that would make a unique and unusual model for your display shelf. For the Modeler: This review is based on the Falcon Industries 1:48 Scale Messerschmitt Bf 109-E model kit although the techniques shown in this review can generally be applied to any vacuform model. This kit consists of one white plastic sheet of parts, two clear cellulose canopies, and a set of pictorial instructions. Details such as panel lines might not be as crisp as injection molds but they re acceptable. Some scratch building is required on the part of the builder. In this kit, simple parts such as the main wheel struts, tailplane struts, and aerial are not included and will have to be made or sourced from another kit or made by the builder. Another thing you ll have to do is find or make decals for your model. Most of these kits were produced prior to the days of the color printer. Fortunately, there are a lot of aftermarket sources online nowadays for both accessory parts and decals to provide professional results for your vacuform model. Overall completed dimensions are Length: 7", Width: 8", Height: 2".

2 000, a & b Here is the vacuform kit from Falcon. This kit, like most of these types, comes in a poly bag. Also shown here is an aftermarket set of decals from MSAP #4802 decals that were used and an accessory pack of parts marketed by Falcon for the kit that was used as well. In general a slow setting Testors tube glue was used for most of the construction along with Model Master Acrylic paints. Deviations will be noted where applicable. A variety of fillers were needed and those are pointed out at their point of use. The other thing that you ll need to do a good job with your model is some references to replicate the actual thing you are trying to model. In this case, Falcon did a pretty good job of describing several variant aircraft equipment and paint schemes and I used that information to make this model but not all vacuform kits include it. Finally, you see that this kit is not super detailed although it could be. In fact, I ll explain more about how construction techniques than the details of this kits finishing because each kit whether it s a plane or armor model would be finished in the same manner as an injection molded kit. Fig 1 & 2 The most striking thing about vacuform kits is that there is only one piece (the plastic sheet) until you cut them out. The first thing to d o is use a pointed Sharpie pen to outline the parts on the sheet. This keeps you from cutting into the part and helps when remove the unwanted perimeter plastic. Just point the pen at the base of the part so that the tip contacts the raised wall of the piece and the barrel rides on the perimeter plastic providing about a 1/16 inch tracing around the part.

3 Fig 3 & 4 Next use the back side of a hobby knife to score the parts around their perimeters. You can use a sharp pair of scissors for larger parts with flat edges. After they ve been scored just flex the perimeter plastic back and forth until it peels off (red arrow) like shown. Fig 5 Some of the smaller parts benefit greatly from being filled. You can use two part resin like this photo shows or even epoxy glue, Bondo filler or two part putty. Note that the small rear wheel parts aren t filled. I elected to use the aftermarket part from the accessory pack for that due to increased detail and strength. Fig 6 After you remove the parts from the sheet you ll see that part of the outline you drew with the Sharpie is still visible around the edges of the parts. You might also notice that some areas (red arrow) appear not to belong to the parts. Don t cut those out just yet as they will aid in removing the perimeter plastic evenly.

4 Fig 7 & 8 Now place a piece of 220 grit sandpaper on a flat surface. It actually helps if you can use some spray adhesive to glue the sandpaper to a flat base like glass or tile. For smaller parts, place some tape on the top side to allow a firm even grip and sand the edges of the parts off evenly in a back and forth motion trying to take the same off of each edge in the same amount. On smaller and round parts a circular motion seems to work best. Fig 9 & 10 After the small parts that are filled have setup cut them out and sand the bottom off to the edges in the same way. In both cases you know you are close to being finished shaping the edges when the edge get down to a thin sliver and finally peels off (right) leaving just the small Sharpie line that was touching the parts perimeter. Fig 11 For irregularly shaped parts like this wing with a dihedral you can t place the parts flat on the sandpaper without risking damage to the part. For those cases bring the sandpaper to the edge of your workbench or table and just work on one half of the part. When it looks good flip it around to do the other half. For the center section if you can t get at it on the edge of the table like the wing surfaces you might need to use a sanding stick or emery board. Notice the rectangular shaped hole on the left side. The boss that molded into the wing to locate the part on

5 was a little too high to allow the intake duct top sit flush against the wing surface. You may run into these features and it s never too early to start dry fitting the mating parts. I cut off the top half with a hobby knife to retain the locator and provide the proper clearance for the part. Fig 12 & 13 The left photo shows the drill used to provide location of the landing gear strut. Whether you make parts like these from scratch or buy them as an aftermarket part you ll have to use a drill that is just the right size by comparing it to the part you re going to install so that it fits just right. Just locate the drill in the right spot using a smaller drill or start a small divot with the hobby knife. You could also make these struts in a more simplified manner from sprue or tube stock. The instructions with this kit recommend that you make the struts from brass tubing for strength. It s the main reason I decided to use the accessory pack because all those parts are made of lead alloy. Fig 14 & 15 The wheels and small round parts in general are difficult to score with a knife. So for that kind of parts it s just as efficient to use a sharp pair of scissors to get close and cut them out. Just be careful not to cut off a section of the part halve itself. Fig 16 The tailplane halves are so thin you can t get a grip on the edges so you need to attach some tape to the top side to sand them off. Use a tape that won t leave a residue like this 3M painters tape.

6 Fig 17 & 18 On many vacuform models you ll find it necessary to cut out sections that are meant for the placement of other parts. The exhaust ports are one of those areas on this kit that has to be removed to accept the exhaust tube assembly. This kit comes with a separately molded exhaust tube assembly to add realism to the build. Being separate pieces that can be finished off more cleanly but even so the kit supplied parts are very simplistic. I elected to use the ports included in the accessory pack for the added detail. Fig 19 & 20 For parts like this I use some five minute epoxy in the inside of the model to set them in place. That gives you plenty of time to adjust their position to get them exactly right. Remember there are no guide tabs and sockets on a vacuform model to aid in placement of the part like there is on an injected kit. You have to make sure the part is in the right position when the adhesive sets. ***NOTE***Before you get too far into the build you need to look at the overall construction to determine what pieces need to be added to the main portion (in this case the fuselage) in order to facilitate finishing and painting.

7 Fig 21 You ll also find that you must drill holes for additional items like the machine guns mounted on the fuselage. Other items like the wing canons and tail wheel will also need to be made. For small holes I like using a pin vise which is a manual drill with very small bits. You can buy them from hobby stores or online. Fig A small pin vise drill can also help locate the larger drill bits used in an electric rotary drill like the one I used to drill out the holes for the propeller blades. For precise placement of a hole I start by cutting a small cross on the part with the tip of a sharp hobby knife. I then drill the holes in that spot holes with a pin vise drill and follow it up with the appropriate electric drill to provide the mounting point for the prop blades. Also keep in mind that you ll have to drill the holes in at the proper angle for the mating parts if the part was filled with resin or putty like the spinner was here. Fig 25 & 26 Remember those sections that looked like they didn t belong on the model we mentioned earlier. Now that those parts have been sanded down to the edges it s time to remove them. You can cut them off with a sharp knife if you have a steady hand but I prefer to use a hot wire to take those sections out. This gun does a great job and runs on two D cell batteries. You can find them for sale online. I ve marked those sections here with a black crisscross pattern. ***NOTE*** Also remember to open up any areas that will need to accept parts like the slot for the taillplanes in the tail section. Because of its shape I was able to use the backside of a hobby blade to etch it out of the fuselage halves.

8 ***NOTE*** Before you get too far into the build you need to look at the construction to determine what pieces need to be added to the main portion (in this case the fuselage) in order to facilitate finishing and painting. Some parts must be installed into the fuselage before you close it up Fig 27 & 28 The parts that are internal to the main body have to be installed before you can join the main halves together. In the left photo the instrument panel pilot s set and rear bulkhead are below the fuselage. In the right photo I used a piece of tape to position the rear bulkhead and used a little superglue to keep it in place. Fig 29 & 30 I ve painted the instrument panel gray-green here with black dials and then glued it into the fuselage (right). I glued the pilot s seat to the rear bulkhead and then painted it and the visible cockpit area gray-green to match the instrument panel. Fig 31 One of biggest problems that keeps people from building vacuform kits is the lack of locating tabs to provide alignment. There is usually a way to minimize the issue by gluing sections together slowly and not all at once. Here I used some slow setting tube glue on the friont section which has several irregular edges to help align that part. Once it s in place add some rubber bands and make sure the whole things is aligned and let it dry.

9 Fig 32 & 33 The next biggest issue to overcome on a vacuform kit is the lack of internal bulkheads to keep seams from splitting out. On injection molded kits the tabs and sockets do that work. On these kits you need to make your own. The front section was chosen to be the first one to join because the nose and instrument panel provide internal bulkheads and the length is fairly short. The back portion of the fuselage is twice as long and with need an additional bulkhead to keep the seams aligned when they are joined and provide strength to keep them from splitting while finishing off the seams. In the past many builders made bulkheads made from balsa wood or styrene sheets and fitted glued them into the interior. I use a two-part putty called Milliput. There are other brands on the market now as well but they should be a two-part putty to provide adhesion, body and minimal heat during curing. In this case I rolled it up into a large and small ball to place into the fuselage. Make sure that they are big enough to be squeezed into a conforming shape inside the cavity. Fig 34 Place the balls of putty inside the open area. Then with the back half still open glue the edges of the fuselage on both halves with some liquid cement or superglue. The putty at the rear will harden and form a base to mount the tail wheel into. Fig 35 Join the two halves together, squeezing the area of the putty bulkheads tightly to make sure it conform to the features and shape of the interior. Snap on a few rubber bands and let it setup. It will harden chemically overnight to form a nearly solid body. ***NOTE*** This plane is a tail dragger. If you use putty for aft bulkheads on a plane with nose gear make sure the nose outweighs the tail. Fig 36 Once dry you can finish off the seams just like a normal model. You ll end up having to add a little putty and rescribing a few panel lines but that is normally the case when building any model.

10 Fig 37 The main wing halves can be joined with the same technique. I put a ball of putty in the middle of the wings on each side and joined the center with slow setting glue and two clamps. I then applied liquid cement to the edges of the wings and squeezed them together and clamped the whole things down to finish setting up. Fig 38 One thing that you ll probably notice with respect to vacuform kits is that joining surfaces tend to have larger gaps. Just make sure the parts are in the proper position and glue them into place. In the case of the wing to fuselage installation you just have to accept that it s going to take some filler to finish off the wing root. Fig 39 Probably the final difference between vacuform and injected kits is the window glass. Typically this is provided in the kits as a buck formed piece of cellulose. Like the kit itself a piece of clear film is heated up and lowered onto a form the shape of the canopy. Just trim the excess plastic off and do the final shaping with a sanding stick. Test fit frequently to eliminate gaps. Finish it off in the usual manner with tape and paint the frame.

11 Fig 40 & 41 After you join the main wheel halve with some slow setting glue, use a small drill to provide a mounting point for the strut axle. Place the struts on the wheel and use some superglue to place them. I then use a drop of epoxy glue to make sure they have a good bond before I paint the wheels. Fig 42 The rest of the assembly follows just as you would with an injected kit with the exception of adding some scratch built parts. In many cases extra detail can be had by using parts from similar injection kits like the propeller and spinner assembly, landing gear, canopy, etc. The aircraft has been primed after taping off the cockpit area here. Fig 43 & 44 I snipped off a length of half round stock to make the tailplane struts. Sanded them to shape and glued them into place with superglue. I also fashioned a radio mast from.010 sheet stock and some aerial from 2lb test fishing line. Fig 45 Later, I drilled small hole on the top of the fuselage behind the cockpit and added holes to mount the wing canons that were made from round rod stock..

12 Fig 46 & 47 Painting follows just like normal. I used RLM matching Model Master Acrylics for this model starting with the yellow nose and rudder sections. I then taped then off after they dried with green painter s tape. Fig 48 & 49 I then sprayed the underside light blue the wheel wells interior green and taped it off after it dried. Fig 50 & 51 I used an airbrush to add the medium gray to the upper surfaces and then gray-green mottled patches for the period correct camouflage scheme. After the paint dried I removed the masking tape and sprayed a light coat of Future Floor Polish over the entire model and let it dry to provide a smooth glossy surface for the MASP aftermarket decal set. I used the Falcon instruction set as a guide for this E-4 version piloted by Feldwebel Wilhelm Erdniss who was captured after the craft was shot down over Kent England in These decals went on pretty well, but some (like the under wing crosses benefitted from some setting solution to conform to the canon bumps.

13 Fig 52 Now it s time to add the rest of the external parts to the airframe. The wheels were painted Model Masters Enamel aluminum and the tires flat black. The struts were not painted and left as natural metal. After mounting the wheel struts into their proper positions with some superglue the wheel flaps were painted light blue on the outside and interior gray-green on the inside and glued to the struts. The propeller blades were painted Model Masters Enamel flat black and glued into position on the spinner with superglue as well. I drilled a hole for the rear wheel and glued it into place with some tube glue. Fig 53 AS I said earlier this kit was not super detailed. There are some features that I feel are really too much of the subject that they can t be left out. The radio aerial is just one of things on an aircraft that has to be there and so then does the aerial. I glued the scratch built mast and stretched the fishing line across it to the rear tailplane using some superglue to affix it into place. After that I glued the canopy into place using some Testors Clear Window adhesive.

14 Fig 54 I used some black acrylic craft paint to take the shine of the wheels and I added a couple strips of black tape to simulate the intake openings on the underwing radiators. Fig 55 Finally, I followed this up with a little MIG black wash on the exhaust ports that I had painted with a rust colored base and the same on the fuselage machine gun nacelles. Brushing on some weathering powder to simulate exhaust stains was the final detail for this build. 999 Overall - This kit and build turned quite nicely. Most of the parts and especially the critical ones, like the fuselage and main wings fit together very well after they were finished off. Test fitting is very important. I don t think I could say that this kit would be able to compete with an expensive modern injection molded version at a contest but it is very presentable none-the-less. If you find a vacuform kit that would help you fill the gaps in your collection or just something that looks interesting to you don t be afraid to give it a try. With the techniques you ve learned here it should just be a matter of determination and patience to get a great looking vacuform model onto your shelf.