Loose wing tanks

[t j]

So there is no silicone between the sharp edge of the fiberglass tabs and the soft aluminum spar? Seems like there needs to be some type of a barrier to keep it from rubbing. Or, a small space to prevent contact?

I suppose you could increase the height of the RTV waves a little onto the lip. The picture in my manual doesn't show it going onto the lip very far if at all.

I would be careful not to get too close to the edge of the tank lip. If RTV squishes out past the edge when the tank is rotated and set in place it is going to make a good bond to the spar with the fabric impossible.

[Esser]

How did you end up finishing this off Jerry?

[Jerrytex]

Oh yeah I guess I did leave this unconcluded. I used the correct RTV silicone. I think it is #739 Owens Corning. I used a real heavy bead and re-installed the tanks. Once it set up, the silicone was still flexible but the attachment was solid as a rock. Huge difference. I re-covered with Poly fiber and went through the process. Everything turned out like it was supposed to and there is no movement between the tanks and the spars. I have several hours on the plane since the repair and no pinched fabric around the tanks.





wing tank 029.jpg

wing tank 031.jpg

wing tank 032.jpg

wing tank 035.jpg

wing tank 037.jpg

wing tank 041.jpg

[jtpitkin06]

For those of you who have not installed your tanks...

When applying the sealant do not use a continuous wavy line that may trap moisture between the spar and tank. Instead, use a series of inverted "V"s with the bottoms not touching to allow moisture to drain.

John

[Av8r3400]

I would also suggest instead of a round bead of silicone, cut the tip to give a triangular bead.

I'm in the windshield business and this shape of bead gives the best contact and "squish" for an even attachment.

[Dave S]

Jerry,

Congratulations on your progress....your repair work in the photos looks good

Sincerely,

Dave S
KF7 Trigear - flying
912ULS Warp

St Paul, MN

[Jfquebec]

Good job...thank's for pic...