The best stringer material to use, wood or metal ??? Model-4

[rogerh12]

Howdy all;
My Kitfox-4-1200 is missing the wood stringers that run along the side and bottom of the fuse. Since I have to buy something, and it has to come truck stock (as the stringers need to be over 8 feet long), I was thinking about going to my local metal supply shop and buy 3/8 O.D aluminum tubing that is 0.035 in thickness and is type 6061. It’s about the same money as ordering Aircraft spruce stringers, and won’t break if someone leans on my plane, however I am wondering if I might have problems later when installing the fabric, or something like that.

Is this a good idea? Another material other alternative ideas anyone? (or maybe I should just stick to the plans)

What have you used?

Thanks

Roger

[Dave S]

Hi Roger,

For what it is worth - the series 7 which I have used 3/8" aluminum tubes for the fuse sides and a wood strip for the bottom. The side tubes were riveted & bonded with hysol to the side fuse standoffs - bottom wood strip is safety wired and bonded with hysol - once the fabric is on - they aren't going anywhere

Can't think of any reason why either option wouldn't work. I think the new Super Sport use aluminum tubing for the false rib supports on the wing while the material previously used on older versions like mine was wood for the wing false rib stringers. There have been some changes on this over the years.

Sincerely,

Dave S
KF7 Trigear
912uls Warp

[rogerh12]

Dave; cool, thanks for the info.
Is that tubing you used .035 in thickness, or the .058 I see listed as well?
Thanks again

Roger

[Dave S]

Roger,

I had the tube size wrong on the first post. The side stringers on on our plane were 1/2" (not 3/8") and I believe the wall thickness is 0.028". The three stringer supports that go through the fuse are 3/8" and I think those are the 0.035" material.

Dave