Remove OLD wing tank, silicone and a tight fit. PITA

[rdooley79]

Hey Guys,



I almost have my old wing tank removed. Only problem is that the tank has no gap between the tank and the front spar. The rear spar had a lot of room and I was able to use some safety wire to work through the silicone and it's separated but the front spar is so close to the fiberglass with no gap that I can't fit even some .020 safety wire to cut the silicone. I definitely don't want to pry on the tank because I don't want to damage the spar. It's very tight and I can't use a screwdriver or a paint scraper, only a razor blade is able to slide between the fiberglass tank and the spar but there is no mechanical leverage to persuade the tank in to coming loose. I don't want to go at it with a dremmel because if I nick the spar, it's done, replace the spar and rebuild the wing. As much as I want a nice shiny set of freshly covered wings. My bank account doesn't.....

It seems that the only solvent is Xylene (Strip-Rite @ HomeDepot) that will soften the Silicone.



Has anyone had a tightly fitting wing tank? What did you do to get it out?



TLDR; silicone adhesive and a tightly fitting wing tank won't budge. How do you remove a tank without damaging the spar?



Thanks Guys,

R

[jiott]

How about trying some even smaller, but strong wire. Surely something in the 0.010 to 0.015" range will work. Maybe monofilament.

[mr bill]

I used dental floss, went thru several pieces but it worked great.

[airlina]

The old factory tech rep recommended heavy fishing line

[rdooley79]

Both great responses!

the other KF forum members recommended the same thing. I'll go that route.

NOT the "get a bigger saw and start cutt'n" suggestion. Besides, who thinks more force and prying on a critical airframe part is a good idea? well some appear to..... :-) gotta give that guy a hard time.

I am going to go get some high strength fishing line and Xylene solvent. between them both I hope to work my way through.

This is a real pain.

[Av8r3400]

I'd stay away from solvents. You stand a chance of damaging the rib to spar glue joints.

[rdooley79]

Fair enough, solvent is scary I agree. I was going to use a syringe to inject the solvent in to the silicone at the middle of the tank. Problem is there isn't even the slightest gap to get started. The only thing that fits so far is a razor blade. So that's why I thought injecting the solvent precisely might be good. But I will hold off considering your warning. It's wise.

Thanks guys.

[jtpitkin06]

The garrot method with dental floss works pretty well. The floss won't hurt your spar. Just keep sawing away with gentle pressure. The floss can get in between layers where you would think there is no room for glue. I've used the method to remove baked on intake manifolds and valve covers.

[HighWing]

My solution is similar to the others, being a retired dentist, I didn't think of the dental floss, but have do some Kevlar thread on hand from a years ago impulse buy and would try that. It has a slightly abrasive feel by nature and likely would work well.

[gregsgt]

Super-braid fishing line. I've removed car windshields with that stuff. Very thin, very strong, and has an abrasive texture.

The other thing you can try is a hot wire cutter. You can make your own like in this video.

https://www.youtube.com/watch?v=qqhHAFgIyCc