Covering a Poly Wing

[fraggin]

Well, it has been some time now since my last covering job. I realized this last night when I had a couple of wrinkles in the fuse of my Sig Riser 2m while covering.
the wing will be next, and it's a one piece poly setup. From what I remember on my last covering job, I did one panel at a time overlapping each one by about 1/8th of an inch.
I tacked the trailing edge ends of the panel, then tacked the leading edge, then the tips and wing joints.
What I can't remember is if it is good to shrink the covering, then run the iron over the rip caps, or if it's the other way around.
Advice anyone?

[mdennis]

Either way will probably work, but I typically tack the edges leaving a small gap for escaping air on one edge. Then tighten it up with a heat gun. Depending on how much wood is under the covering you can run a cloth over it as you are heating it and it will tack to the wood or you can go back with your iron and tack it down on the ribs.

[jbrandon]

I do about the same only I cover the top first wrapping the covering around the leading and trailing edges about 1/8”. Then I cover the bottom cutting the covering at the leading and flush with the trailing edge. The over lap from the top will give a good seal. I shrink when all panels are covered and sealed. I do not run a iron over the ribs as it will leave light scuff marks (not that it will make much difference after the first few flights). I use a heat gun on highest and use a cloth on all attachment points and the ribs once the covering is tight. As far as pressure build up I punch pin holes in each bay on the bottom of the wing. Be very careful with the high heat gun, it can burn a hole faster than you can say…

mdennis: Where do you fly in Shawnee? I am in Gladstone.

[fraggin]

Thanks for the tips...

[becsta]

Fraggin,

I use this stuff over here called Profilm (which I think is Oracover in the US).

How I do my wings (ribbed and fully sheeted) tends to do the job well. I cut out the covering film to slightly oversized, and lay it down on the wing half. On low heat, tack down the covering along the spar in several places (so it doesn't move around).

Then run the iron along the spar along the complete length of the wing.

Then tack down the rest of the film by even strokes of the iron from the tacked area, all the while keeping tension on the film.

Do the edges at low heat, cut and trim accordingly.

Do all four "halves", bottoms first.

Once the wing halves are completely covered, set the iron to middle heat, and run around the edges. Set the iron to high heat, and evenly shrink the film.

One helpful bit of advice - use some weights to keep the wing from moving, and to keep it flat on the table. If your wing isn't flat, you'll introduce warps and bows.

- bec

[fraggin]

Thanks for the tips guys. I have all four wing panels covered on the bottom and need another roll to finish the it tops. By the time I had finished the fuse, the technique came back to me. The fuse has a few wrinkles, but are only visible up close. The only other complaint I have is that somehow the rudder has a slight warp. I didn't notice this until the vertical stab and rudder were fastened to the plane. I'm not sure how I will remove the warp, but am currently thinking about clamping the vertical stab and the rudder along side a wide piece of light plywood and then removing the wrinkles from the other side of the rudder. Hopefully this will do the trick.
So far, the entire fuse, tail and wing bottoms are covered in econocote black. I haven't decided on the detail work, but think I may cover the tops of the wing in translucent red.

[FrogChief]

Thanks for the tips guys. I have all four wing panels covered on the bottom and need another roll to finish the it tops. By the time I had finished the fuse, the technique came back to me. The fuse has a few wrinkles, but are only visible up close. The only other complaint I have is that somehow the rudder has a slight warp. I didn't notice this until the vertical stab and rudder were fastened to the plane. I'm not sure how I will remove the warp, but am currently thinking about clamping the vertical stab and the rudder along side a wide piece of light plywood and then removing the wrinkles from the other side of the rudder. Hopefully this will do the trick.
So far, the entire fuse, tail and wing bottoms are covered in econocote black. I haven't decided on the detail work, but think I may cover the tops of the wing in translucent red.

here's some ideas ;) :

http://www.rcgroups.com/forums/showthread.php?t=601193

[Mr B....]

I cover the bottom first then the top. The same with the fuse bottom, sides, then top.


Merrill

[s14slide]

well since this is about covering a wing and what not, does anyone know of a good online tutorial on covering planes, and I really do not have anyone around who could even show me how.

[flying_flip]

I cover the bottom first then the top. The same with the fuse bottom, sides, then top.


Merrill
I do what Merrill says :)
Also a little trick I found is after covering the bottom of the wing, take a pin or sewing needle and poke a hole or two in each bay (in the corners) When you cover the top, the holes allow for the gases to vent out.

An old timer joked that it has an added advantage that when you are thermalling and the wing gets hot, the escaping hot air increases the lift of the wing :)