Help with fuel tank replacement - 1992 KFIV Speedster

[Geowitz]

Just a side note... I would guess they moved the filler opening so the wings could be folded without spilling fuel when the tanks were over half fuel. Problem with that though is you can't fill the tanks to full when they are in flying position.

[avidflyer]

I would not mix different kinds of fabric myself. I recovered a set of wings this summer from a Kitfox 4. It had one new tank and one old one. Nothing wrong with the old tank so I left it in. I did make a provision that would help if I ever had to change it out. Here is a picture of what I did. Basicly covered the wing except the area over the tank, then put a separate piece of fabric over the tank area. How does this relate to your question? I would cut the fabric long enough to wrap it around the rib and glue it in as best as I could. Then the new fabric would be glued down over the old fabric. I did rib stich these wings, and that would help to hold the joint together as well. In the last year, I recovered 5 wings, plus the rest of one airplane using the poly fiber system. JImChuk

[jrevens]

Bob,

I hesitate endorsing any particular product, but I do believe that Oratex would work very well for this. As far as color matching, the white Oratex is a very common white that matches the color of the powder coating that Kitfox has done, for instance, almost perfectly. As was said, it can certainly be painted, but then you might as well just use the same system as the original covering. It will have a different look from the rest of the fabric of course, but might look OK to you. FWIW, I would certainly consider removing & replacing just the fabric over the tank. Depending on how well the old tank is "glued" in, maybe the bottom fabric would have to be removed too? Others who have done this could lend a lot more educated expertise than I. I would cut the old fabric to leave extra over the tank on both sides, and then fold over & glue that to the ribs. Then I would cut the Oratex to overlap the 1" cap strips on both ribs, as well as extra to overlap around the trailing edge as well as the leading edge. If you had to do both top & bottom it would be good if you could use just one piece, starting at the trailing edge then curving around the leading edge and then around & overlapping at the trailing edge. The Oratex glue would be compatible with the painted surfaces of the original fabric - just scuffing & thorough cleaning is needed, to my knowledge. I suspect that you might possibly do the Oratex cheaper for this small job, considering the cost of the various chemicals/paints needed for PolyFiber.

That all being said, PolyFiber might be cheaper. Of course you will have to deal with masking and all of the painting steps to get to where you want to be.

My best advice would be that whatever you do, try to make sure it's something you can live with and be proud of, regardless of the potential time or expense involved. Consider the possible effect on the resale value of your airplane as well as your satisfaction every time you have to look at it.

[jiott]

John, you mentioned resale. That is one big reason in my mind to stick with the original fabric system. Any new owner may not be aware of a different type of fabric and its unique methods of application if it is in only one spot on the airplane.

Regarding matching whites, not as easy as it might appear. This summer I had to recover an elevator half. The original white paint on the other half was supposedly color matched by the paint supplier. He did fairly well, but it is not perfect-in bright sunlight you can tell a difference. Not really noticeable because the elevator halves are separated by the rudder, but if those two panels were butted together (like Bob is going to do) it would be much more noticeable. That's why I recommend making the patch seams on hard points like ribs, spars, trailing edge. These places get finishing tapes to break up the large flat surfaces.

[Bob Brocious]

Thank you, Jim and company. I appreciate your thoughtful replies. I'm enjoying the process of learning more about my Kitfox. I'll post more pictures shortly.

[cap01]

some pics in my album of when i replaced tanks. only the top fabric needs to be removed over the tank. my project was a little more labor intensive as i removed 6 gal tanks and installed 13 gal tanks. i had to open the wing a bay farther out from the end of the tank as the drag tubes had to be relocated . it may cost more for paint but its worth it to paint the entire wing. new whites and old whites don't match .besides sanding and blending sucks, the second wing i painted the whole wing .

[dholly]

Or if you like the look, wrap a complimentary color Oratex around the entire wing, top and bottom, from root to rib outboard the tank(s). No painting and a new paint scheme for the new year!