hi all
I AM BUILDING A 4*60 (MY FIRST KIT) AND I HAVE RUN INTO TROUBLE. WHEN I FINSHED ONE OF MY WINGS I SAW THAT THE WING IS BOWED. I THINK IT IS FROM USING A BUILDING BORD THAT IS NOT HARD ENOUGH. THE TABLE HAS A FOAM TOP AND I WAS USING FOAM BOARD TO STICK PINS TO. ONE WING DID FINE BUT THE OTHER IS BOWED HOW DO I GET THE BOW OUT. CAN I WET IT WITH WATER AND USE HEAT? HELP!! HELP!!HELP!!

You might find something here.

http://www.rcuniverse.com/showthread...ht=warped+wing

Good luck

Stevee

If the bow isn't to bad the bow can be taken out by tighting the covering,sometimes can brace the ends and put weight on the high part of the bow then wet it or steam it.In the future building is just opposite of the girlfriend,flat,flat and flatter is best.

I would not try wetting it. I tried that with a Sig Somethin Extra and really made a mess of things. Now I soaked it, and tried the heat, and wound up with a wave in the sheeting, of coarse the Somethin extra has very thin sheeting. But it also twisted the wing, and the warp was still there toboot. I wound up taking stock in ca debonder and using heat to soften epoxy to take the wing back apart. You already have been given some good advise I would say go with it. Always happy to help if I can. Garry

I just fixed my wing on my Sig LT 40. The trailing edge of one wing was bowed and I didn't notice it until I had the wing half together. The bow was curved in the middle. The other wing was built on the same board and was not warped.

I soaked just the trailing edge by standing the wing upright for about 24 hours in 75% water and 25% ammonia. Fumes were terrible. I then laid the wing on a flat stable surface and set a weight on just the trailing edge in the middle for two days without messing with.

The wing came out straight as a board. The only thing was that the trailing edge had swelled from the water and need some sanding on top and I had to take off about an 1/8th inch off the back side. I did all that after I mated the two wing so that I could tell where I was on the re-work. A veteran flier told me to do this. You might try it. Or re-build the wing from scratch. Did not appeal to me, this is my first kit.

If the wing has a slight "BOW" to it, but it is not "WARPED", you have two choices...

1, leave it alone, it will fly fine.

2 cut off the sheeting, top spar and shear webs, and start over.

If the wing is bowed, the top spar is shorter or longer that the bottom spar. If you go wetting things or putting weights etc., you are probably going to WARP the wing, which is MUCH WORSE than a bow!

bowed wings (not twisted) will not be fixed by soaking in water. Fly it the way it is and use trim to correct any flying problem.

for the future - the wood used for the spars usually are not perfectly straight. They tend to have a slight bow. When placing the spars you must place the bow (bend) in the upper spar opposite the bow in the lower spar.... so the bend in the spars are opposite each other like this ( ) and not like this ) ) or ( (

If the bends are going the same way the wing will always be bowed and is probably what caused your problem.

Did this make sense?

Thanks for all the great help. I think that my best bet is to leave it. there is no twist, it is just bowed in the middle. I don't like the idea of starting over and that seem to be the only way to fix it for sure. If it will fly O.K. its not worth the trouble. I'll have a new building board before the next one!
thanks for all the great help!!! Mickey!

A lot of guys use foam, or other soft things as building boards so they can stick pins into it. I would prefer to build on a granite table if I had one (providing it was flat) and use weights to hold things down. That way, I KNOW my building surface is not going to flex!