Jon B

My Feedback: (2)

I'm working on an OMP 47" 540 Edge. I used wood glue to glue the balsa sheeting to the foam core. Initially the fuse was straight as can be but after a few days it developed a warp. When laid on a flat surface, the center of the fuse is about 1/4 inch up off the surface. I was thinking that if I wet both surfaces of the fuse and then weighted it down on a flat surface for a couple of days, this might take the warp out.

Any suggestions would be greatly appreciated. I'm new to the sport and this is my first kit build.

Thanks,
Jon B.

AFSalmon

My Feedback: (3)

What kind of glue did you use to sheet this and what process? A few have had this happen when using some glues or not assuring their table was flat when building but it may be able to be fixed. Try the water and ammonia mix and wet both sides but don't soak them. Just wet the balsa enough to loosen the grain structure and then weight the fuse down on a flat surface. You will want to raise the front and back so you exaggerate the bending the opposite way it is now. Give that a try and let us know if it works.

Jon B

My Feedback: (2)

How much ammonia should I add to the water? I used Titebond II "Premium Waterproof Wood Glue." As I mentioned in my original post, the fuse was perfectly straight initially. The warp showed up a few days later.

Thanks for your suggestions.

AFSalmon

My Feedback: (3)

Hmm, odd it would warp after initially curing straight. Could be a humidity problem? Not sure. I use only water and never amonnia but I know some do mix say a tablespoon's worth per spray bottle. Not sure about the range of mixture but try water fix. Use warm water and let me know if you make some progress.

Spacey

Ugh shucks sounds like he is having the exact same problem I had on my first little Yak. It is definitely a humidity problem as well. Thing I had happening is that the fuselage didn't dry enough inside the press and as soon as you took it out it would dry out completely but then warp again. I eventually went to extremes with water thinned wood glue painted onto the sheets. Ironing the sheets after I wet it. It was a bit of a tricky one as you would get it straight and then the next day when you get to it it's warped again. I got mine close enough eventually though and countered some of the warping with the capping bent the other way and such. She is still ok to date and she's nearly a year old now. My mate's never came right (Same problem) so I had to physically pull off one side of the sheeting and redo it with epoxy. This however solved the problem quickly and fortunately he didn't use alot of glue on the original sheet. It took me quite a while to get the original sheeting off but if you work it carefull you won't damage the foam at all.

So if you can't get it straight at all just pull one side of the balsa off carefully and put on a new sheet with some thinned epoxy.

dprater

Posted: Sun Jul 10, 2005 5:08 pm Post subject:

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Well I hate to admit it but the first profile I built with a foam-sheeted fuse I too had a bow in the fuse about 1/4" or more. When I put all that weight on the fuse it bowed my work table.
I took a hand plane ( a wood tool plane) and set it where it would not cut much at a time and removed all the sheeting and bought more balsa sheeting. It took about 1/2 hour to remove all the sheeting. And was worth the trouble to me.

Guess what!!
I put some support under that table!!!