General Tips | Radio Equipment | Adhesives | Tapes | Hardware | Covering Materials

General Tips

Shaping

I've got a sort of procedure for shaping EPP fuselages:

1. Slice the corners off the fuselage at a 45 degree angle. This will leave a sort of "octagon" shaped section.
2. Shape the canopy area. I draw two lines on the windscreen that show the flat, bullet-proof glass panel of the windscreen as on a full-scale plane on the warbirds, and use those as guides to smooth the canopy contours into. Plastic models are a great place to look for contouring cues.
3. After I have this very rough shape, I slice the corners off the "octagon". It will look pretty darn smooth after that. This is followed by gentle but firm sanding to get everything really smooth and round. Even the Foam Wulf's nose can be made to look very round by going for an elliptical section.
4. On the warbirds, the radius at the fuselage's bottom-rear corners is not as extreme as the top's (which should be almost "round"), but instead will leave a fairly flat area immediately behind the wing. As the fuselage tapers toward the rear, the radius catches up to the fuselage's diminishing width and it'll be very "round" at the bottom of the tail.

Practice your shaping on the scrap chunk before you commit to the fuselage itself. You'll get the hang of it real quick. Always have SHARP blades for your knife on-hand. I use up about three or four blades shaping one fuselage. I can shape out a fuselage in about fifteen minutes, and it looks great. Remember - it's not brain surgery; just a toy airplane! Keep messing with it until you're satisfied. I've seen everything from completely 'un-shaped' to 'very streamlined' on these planes and they all flew fine, but the carefully shaped and streamlined ones are always a little lighter, faster and prettier. Two tools I've also found very handy are a stainless steel utility knife with a blade about 4 inches long and a block of wood with a belt sander belt glued to one side (40 to 60 grit). These two tools in conjuction can also make quick work of shaping a fuselage.

After shaping with the knife and/or gritty sanding block, you can also go over the whole thing with a sanding block and a little finer sandpaper (80 to 120 grit) to get everything fine tuned and looking slick. The secret to successful sanding is to use light pressure and sand in one direction - hard 'back and forth' sanding will nearly always result in the foam chunking out (that goes for all grits).

Taping

• When using tape, don't be afraid to "split" it parallel to the filaments to get pieces that fit tight contours more easily. This is a good technique to use to get the nose area well taped with no wrinkles.
• If you suspect you'll need to add lead on the nose for balance, then throw one more layer of tape on the nose areas. This is very common on the TG-3, as every one needs about three to four ounces of nose weight for proper balance. The extra wraps of tape do add strength, and you may as well put the weight to good use.
• For an extra heavy duty wing-to-fuse joint on the warbirds, slot the wing to pass a strip of tape from one side of the fuselage, through and under the wing, then through again and up the opposite fuselage side. Cover the tape with covering material and it's invisible. This makes it REALLY strong!
• On the TG-3, 1-26 HLG and 1-26 2 Meter models, it's also a good idea to throw an extra wrap at the front and rear ends of the wing opening to toughen it up a little; especially if the plane will be used as a trainer and subsequently subjected to some extreme abuse.

Applying Covering film

• After shaping the fuselage with a knife and / or sanding, go over the whole thing with 150 grit paper one more time then brush and / or vacuum all the EPP "dust" off before spraying and taping.
• In the Combat Warbird manuals, we specify to "prime" the nose area of the fuselage with covering material prior to taping. This is really optional, but will greatly improve the tape's adhesion to the fuselage. The film sticks like skin to the foam, so it's a good idea to do this if you happen to have enough covering material on hand. Our factory planes have been built both ways and both have worked, so don't lose sleep over it.
• When covering, don't try to shrink anything super-tight until the entire component has been covered. If you covered say, the bottom of the fuselage, then tried to shrink it out, it would never get very tight. Instead, cover the whole fuselage in sections, as you would on a regular framed model (bottom, then sides, then top), seal the mating edges, THEN shrink out the whole part. This way, you'll get a tight, smooth finish over the whole part that will be hard to distinguish from wood construction! The same goes for the wings; cover all the surfaces, trim and seal the edges, then do a final shrink of the film with attention to even shrinkage. You're making a heat-shrunk 'bag' around the parts, not covering a rigid structure. If you tried to shrink each piece of covering individually as you went, the covering would simply pull the foam out of shape leaving a crooked component with wrinkled covering - not the desired effect.
• Turn up your iron! For final shrinking of the covering film, you can run your iron quite hot, as long as you don't linger over one area for too long. The EPP has twice the temperature threshold of ordinary styrene foams. We don't recommend using a heat gun, as it dumps lots of heat in a hurry, and is far less controllable than an iron. If you do use a heat gun, take care not to blast away until the thing melts!
• When covering over the taped areas, the 3M Super 77 spray adhesive isn't really necessary. However, be sure to lightly sand all the tape to knock off the release compound on the surface before applying the film.
• Lots of folks say they have trouble covering the Coroplast tail components with the iron-on film. We do it here all the time and it works great IF you follow these steps.. Be sure and WASH the Coroplast parts in soapy water and rinse them thoroughly. Next, spray the area you're about to cover with 3M Super 77 - don't let this stand for more than about 30 seconds before placing the film; you still want it to be a little "wet". Now, apply the film (no heat). Don't try to smooth it out with your bare hand, but instead use a cloth rag. Work from the center toward the edges pressing it down so that no air bubbles get trapped under the film - this is the crucial step! If you get a bubble, pop it with the point of your knife or a pin and smooth it out. Our tails covered this way stay pretty for a long time. If you feel compelled to use the iron, use it only at VERY low temperature and don't let it sit in one place for long, as it will ruin the Coroplast. Obviously, you can avoid this all together by using self adhesive film. You can paint these parts, too, and Testor's spray enamels seem to stick pretty well as long as the coroplast is washed with soapy water first.