Please share your plastic film COVERING secrets.

[Len]

Guys,
I have a few projects coming up that require covering the sheeted wings and tail. I really want the wings to look painted and perfect, and I have seen some wings that I thought were painted only to find out they were covered with heat shrink film.

I thought it would be neat if we could all share some of your best secrets for covering with Iron on.
I'm going to give the vinyl covering that Stephane wrote about a try too.

Thanks for sharing

LEN

[yyz]

If you're using white covering over obechi sheeting, you may want to check into some uber Oracote that has silver backing to prevent the yellow of the obechi from showing through. Yeah, it's subtle but noticeable. I believe Rick Shelby mentioned that you can only get it in Europe but it's probably worth looking into.

The real heat shrink covering ninjas will probably scoff at this but here's what I do.

1) Buy Ultracote (aka Oracover)
2) Make sure you didn't buy something other than Ultracote
3) Buy a small covering iron from Tower Hobbies
4) Heat the iron until water dropped on the iron sizzles (in Ultracote instructions)
5) Put an old sock over the iron and tie it tight with a wire tie (be safe for both you and your partner!)
6) Cut the covering an inch larger in all dimensions for the top of the wing/surface
7) Wipe down the wood with a tack cloth (removes dust and generates static electricity which holds the covering in place)
8) Remove the backing from the covering
9) Center the covering over the top section to be covered
10) Start in the middle, both span-wise and chord-wise, and work your way out progressively along the high point to the tip and again to the root
11) If you've gaffed in your centering abilities, you can pull this off and start over
12) Again, from center, progressively start ironing from the high-point of the airfoil towards the leading edge a little at a time, working towards the tip and then towards the root
13) Turn surface around and repeat, working towards the trailing edge
14) I aggressively make sure that there are no air bubbles and that the covering is stuck down EVERYWHERE (inviting disagreement here).
15) At the edges, I ensure that the covering is tacked down at as close to the same place on the edge is possible
16) Now, I carefully trim the over hang to about 3/8"
17) Working from the centers of the edges out, iron down the edges, again aggressively. When I do it "right", I see a little bit of color on the iron.
18) Repeat for bottom surface but trimming flush with edges and then SUPER aggressively iron down the edges.

I'm probably a creature of habit having done it this way for 30 years but that doesn't make it the best way. Really curious what others are doing.

Mike

ps: acetone cleans up the melted covering sometimes left behind

[Len]

Nice instruction sheet Mike,

My technique over the years is pretty much the same, although I did pick up a few good pointers there. Thats why I thought it was good to start this thread. Its not whats right or wrong, its what works for you.

I find its a great idea to sand the surface if the wing with 400 paper before covering, then vacuum it with a brush attachment.
I think the most common mistake we all made or make is to set the iron temp too high. All we want is the glue to activate and glue the covering down, not shrink it. ( over a solid surface.

Do you do the top side first? I have always covered the bottom first and then you would not see any seams.

Great info, I hope others will post their techniques too.

LEN

[yyz]

Yes, I do the top first so that the overlap is on the bottom. When I cover the bottom, I trim the covering as close as possible to the leading and trailing edge so that the seam ends up in the middle of each edge.

Oh, another thing. When doing wing tips or other curved shapes, I cut the covering every 1/8" or so and iron the little tabs down progressively along the curve.

Good call on the sanding and vacuuming. If you have carbon or glass cloth under the obechi, I have found that you can do a LOT of sanding, even though the wood is typically less than 1/32" thick. The black from the carbon will start showing through when you need to stop sanding. Surprisingly, the Oracover is opaque enough to cover the carbon.

[target]

A little bird told me that spraying primer over the Obeichi is the hot ticket...
Kills the wood grain from showing through.
I would think additionally, if you used a light colored, off-white primer, then that yellow that Mike refers to won't happen.
Might try that on the resurrection plane.

R,
Target