orbsah

Hi all- I'm having a tough time sheeting the top of my Top Flight DC-3 Fuselage. I'm trying to wrap 3/32 balsa sheeting over the curved surface. The structure consists of several formers and stringers. I did one section already and in order to get the balsa to curve, I had to wet it quite a bit. Once wet, I was able to curve the sheet OK, however I found the next day after everything dried, the balsa must have shrunk (or it expanded too much when wet) resulting in a faceted surface. Rather than a smooth "C" shaped surface, the sheet now is slightly flat between the stringers. Any suggestions before I move on to the next section? Thanks.

MinnFlyer

My Feedback: (4)

Use less water and only wet the outside of the curve

orbsah

Yes I tried wetting only the outside first (and just a little). Then I slowly tried to massage the sheet to conform. However the sheet kept splitting so I soaked it more. I vaguely recall seeing some comments about using rubbing alcohol instead of water??? Is that any better? Thanks.

MinnFlyer

My Feedback: (4)

Not alacohol, but ammonia is supposed to help.

I don't use either. If the wood won't bend enough, wet the outside, let it sit for a few minutes (it will start to bend by itself after it sits a while) then bend it as much as you can safely (without it splitting). Tape it in that position overnight, and repeat the next day.

Lnewqban

These may help:

http://www.tpbweb.com/media/catalog/404.pdf

http://www.tpbweb.com/media/catalog/412.pdf

http://tpbweb.com/media/catalog/611.pdf

Try to find and use A-grain balsa.

It seems to me that bending a 2-3/4" wide x 30" long piece of 3/32" balsa sheeting (less than the sofest type) is not easy task.

The formers and the stringers are not the most solid surface to achieve a nice round C shape.

Gray Beard

My Feedback: (-1)

Pretty much everything Mike said but I do use a blend of 50/50 water and ammonia, it does seem to soften up the wood better. Sometimes the wood I get is just too stiff and heavy to bend well, I keep a supply of contest grade wood on hand with more open grain just for sheeting bends and contures.

jaka

Hi!
Get a nother sheet of balsa. See to that you get A-grain!
Amonia does not help any better than water!

Mk23socom

My Feedback: (7)

Iuse 50/50 water alcohol and I have never had a problem, would have used windex like Ihave heard about but I had the bottle of 50/50 already handy..

da Rock

Straight grain wood and water.

Die cut kits relied on how wetting balsa softened it. The kit makers back then didn't need anything else, just water. OH yeah, and a sharp die, which it usually wasn't. The harder woods need the harsh chemicals to break down the stuff in them that made them stronger and heavier than balsa. It's not there in balsa to need those chemicals.

ARUP

Use planks not sheets to cover your fuselage. After planking, wet the planks with a little water and rub Elmers Wood Putty mixed with DAP drywall filler 50/50 into the seams. Let dry then sand.

WhiteRook

My Feedback: (38)

what i do is wrap the sheet arround a large plastic bottle and wet it , then when it dries i'll elastic band it to the fuse , wet it again and it will form to the shape well. you have to find a bottle or jar close to the diameter of your fuse . for compound curves its a little tougher.

sensei

Spray the OML (outer mold line) with Windex and allow to set for around 5 minutes. tape down around the stringers, templates, or whatever your trying to fit. Allow to set overnight and completely dry out before removal and your ready to bond down.

Bob

orbsah

Thank you everyone for the great suggestions!

LesUyeda

Ace elastic bandages, as in wrapping knees, elbows, etc., work great, and don't leave marks in the balsla.

Lesw

Gray Beard

My Feedback: (-1)

I gave them a try and your right, no marks or grooves in the sheeting like rubber bands.

Mk23socom

My Feedback: (7)

wow, what a great idea!..