How do i straighten warped ribs?

[ken nougaret]

I'm ready to install the ribs on my horizontal stab and elevator. But after untaping the bundle of ribs and leaving them on the table for a week they have all warped/curved. Can someone tell me the best way to straighten them before i glue them on. I was thinking of putting a wet towel and ironing to steam them.
Thanks, Ken (Zephyrhills)

[Tom Waid]

Hello Ken,
I'm speculating, so I may be completely wrong. If you have your ribs in an un-air conditioned place, the side of each rib that is touching the table may be absorbing less moisture than the side facing up, causing them to warp. We've been living in a steam bath lately. If this is the case, maybe bringing them into an air conditioned place will fix the problem.

When you have them mounted, each rib will either have a stiffener or have a uniform flow of air around it. Plus you'll have the ribs coated with varnish.

[DanB]

Ken,
Tom's idea would certainly be worth a try if you have the time to let the moisture content balance. I think your idea of wraping them and hitting them with steam is a good idea as well. Another thing I do in the wood shop (I teach High School woods) is I will just immerse a piece of wood in water and saturate it (put a weight on and hold it under) for an hour or so. Afterwards, press the wood between two stable (flat) surfaces and set it out in our AZ sun to dry for a day. If you are lacking AZ sun...see if your wife will mind you taking over the oven and set it on a low heat (perhaps between a couple 1/4" pieces of plate steel. Once they dry they should stay put.

[dginok]

Ken,

I had the same issue with the vertical stabilizer ribs a few days ago. I did a combination of things like 1) gluing on the stiffeners while the rib was clamped down flat on a bench, 2) gluing the rib in place while it was clamped to some aluminum straight edges which were clamped to the VS tubing, and 3) using some 5 lb weight plates to force the rib into a plane while epoxied in position on the VS. These all seemed to work fairly well from what I can tell. Not sure how well they might apply to the HS or elevator. The previous builder took care of those for me.

[ken nougaret]

thanks for the replies. i think i'll try tom's method since it's so simple. and it has been a steam bath here in florida.
ken

[jtpitkin06]

a heat gun on low or a hair dryer on high works great for removing warps from the ribs.
JP