Sneasle

hey guys, im workign on shrinking the covering down on my p-51 wing. i borrowed a heat gun from a friend at work. How long does it usually take to do this? I know this wing has ALOT of wrinkles in it.. but i have been workign on it for 30 min and the coverign over the open parts of the wing still isnt tight. also, does anyone have any tips in how to smooth out wingtips and other curves? or tips on how to get out these annoying little wrinkles that i find everywhere?

indoorff

My Feedback: (2)

Sneasle - the heat gun works in seconds. The covering has to be reasonably taught when first applied with an iron. When you use the heat gun to shrink it, the covering only shrinks so much, and if it is too loose to start, well you are out of luck. Keeping the heat on for longer isn't likely to help. Also, make sure the covering is WELL stuck down around the edges of an open structure, because when the heat gun starts to shrink this area, if the covering comes loose from the edge, it will not shrink evenly and you will end up with wrinkles too.

As for the wrinkles you say you find everywhere, I do not know of any way to remove them. You may have luck pulling the covering off and re-sticking it, or you could re-cover the section, or just live with them.

For compound curves, it can be very difficult not to get any wrinkles. My brother seems to have mastered this technique. He covers the wing up to the tip, leaving enough covering overhanging the tip, then get the heat gun, and heat the extra coverwing while applying some force to pull the covering around the wing tip. Work slowly, lots of pulling and lots of heat, and you will hopefully have success.

Monokote covering is not easy, it just takes practice. My first plane looked like &*^%, and every plane after that got better. You get to the point eventually where you get a great looking model everytime.

Cheers

burtcs

Sneasle: Covering with any of the various “coats, spans or films” works pretty much the same way as Silk, Silkspan or Tissue. It’s all a mental state, some are easier to work with than others. My personal plan of attack is to cover the stab, the fin, the wing and finally the fuse. in that order - that's me, you can do it differently. Removing the covering from the wood is your problem. I work with a sealing iron, heat gun and trim iron. You gotta have a sealing iron.

When I cover a stab I work from tip to tip and I try to do this over a spar (if I can, if its sheet then just tip to tip). Tack the covering down to the tip, pull it snug (your not trying to kill anything here just tight) then tack the other tip. So to recap it's now tacked to the tips. Then I tack the covering to the root of the stab, front and rear. Tack it at the leading edge pull to snug it then tack the trailing edge. Recap: your now tacked down at four places. If you look closely you'll notice you've formed a diamond in the covering and that diamond is snug or tight.

I usually continue from the root tacks to two places adjacent from the center tacks, maybe 1/2" to an inch as an example. Same drill, tack the leading edge, pull snug, tack the trailing edge. Then do the same thing on the other side of the stab. You have enlarged the tight zone of the covering. At some point you'll need to go back to the tips and do tack downs adjacent to the first tacks.

Ok I'm going to really spill my guts here: You are working the slack towards the outer corners and the centers of each axis are getting tighter. This is true for every thing else your going to do. If you use a cooler heat for tacking you can pop tacks loose and move them a bit. Why? As you get more covering tacked down snug or tight you'll notice that there is often slack showing up in what you've done before, you need to get rid of this stuff. At this point they are just tacks (i.e. spots). When you’ve got down primo – snug and tight then you can seal around the edge of the whole piece and shrink now or later.

These "coat" coverings all shrink at different rates, you need to experiment with them even if that means a test panel. My experience is not to count on the shrinkage to remove wrinkles. Those should have been removed when you stuck the stuff down.

Not to preach you need a couple of projects under your belt before your covering jobs start looking good. As always good luck and have fun.

HTH - Steve B.

Sneasle

ok, thanks guys

ComfortablyNumb

It would be helpful to us newbs. If someone that knows what they're doing, would make a "Covering Video". I'd download it. [sm=stupid.gif]

Edit; Anybody know of one?

rainedave

My Feedback: (1)

RCU has both a Beginners Forum and it's very own Search Engine.

Use those resources to find things like this:

http://www.rcuniverse.com/magazine/a...article_id=726

ComfortablyNumb

Yeah...uuumm. Why break a newb tradition, when I can dig up an old thread?

Also, Thanks for the help! That link is saved.