I volunteered to help out my friend by covering the flying surfaces for his 120" Edge. I've got a fair amount of experience with both Monokote and also Ultracote, but I've never tackled anything of this size. The wing panels are solid, constructed from balsa covered foam. I was wondering if there are any secrets to covering a surface this large. I was going to use the same technique that I've always used on smaller wing panels, just tacking a corner, pulling, tacking another corner, pulling, tacking another corner, etc. Then going all around the perimeter pulling and tacking until I have the entire perimeter sealed and free from wrinkles. Then I gradually shrink the middle, using a glove to put a little extra pressure on the heated surface. I was also planning on using a woodpecker on the balsa to give the gases somewhere to go. I did one of the ailerons this afternoon, and everything went OK, but I did have lots of trapped gasses to get rid of when I got to shrinking the final surface. Any tips on how to prevent this from happening?

Does this sound like the right way to do it? The material I'm using is Ultracote.

Thanks

Vince

I've never covered anything that big either.

For trapped gas pockets, just ***** them with a pin and then run your glove over the bubble. Working from the outside in. Gas will escape, then rub the spot down where the hole was. Never see the pin hole. Flat finish.

I try and run my hand over all the bubbles and "chase" them all into 1 big bubble. Smooth down the monokote as you work the bubbles towards the center. ***** it with a pin and let the hot gas escape.

ANY solid surface is best done as follows:

Pull and tack the 4 corners and the middle. (Make sure the tacks are light since you will be pulling the covering loose from the tacks)

Start in the MIDDLE of the surface to be covered and IRON toward the edge. You will most likely need to pull one (or more) of the tacks loose in order to keep tension on the covering while ironing.

Covering solid surfaces this way greatly reduces (or eliminates ) the bubble problem since the chance for air to be trapped is minimal.

I recently did a fuselage in Monokote (notorious for bubbles). The fuselage was 48" long and 9" in diameter at the nose. I had 6 small bubbles total in the covering and 2 of them were on one of the overlap seams.

On solid surfaces, I have better luck working the material down from the center out, i.e. with just enough heat on the iron to activate the glue, first iron down the center then work the attachement area out toward the edges.

Well, it's done and it came out really nice, if I do say so myself. I found that I started way too high with temperature, the first aileron had a lot of trapped air. I worked that out and actually went back and read the Ultracote instructions again, DUH! After lowering the iron temperature to about 250 degrees, it worked perfectly. Tacked around the perimeter, starting with the four corners, pulling and stretching as I did it. Started ironing in the middle as you guys recommended and slowly worked out to the edges. I actually cut up an old pillow case and used small pieces of that between the iron and the Ultracote. Worked better than a sock in my opinion. You don't need a lot of pressure, just melt the adhesive and then lightly press it down with the glove. At 250 degrees, there is a small amount of shrinkage of the film as well, which removes any wrinkles. If you do a good job stretching it and tacking it, you won't have many wrinkles anyway. I found that by moving the iron in small circles, it didn't make any marks on the very soft contest balsa under the film. Of course, I used the woodpecker on all surfaces prior to putting the film down, then took a tack rag to remove any specs of dust. There are no bubbles or wrinkles on any of the surfaces. I really love working with this Ultracote. It's so easy to work it around curves and such. It was a slow, lengthy process, but the results were much better than I had expected. Thanks for all the tips.