Touching up fabric paint

[fastfred]

I will try that/

[Tomfox]

I have recently noticed fine bubbles and paint softening around my right fuel tank - some in center and some in edges of tan. This is on top. I followed the poly manual painting. Are there any ideas on the cause. I took a pic but am not sure how to attach it to this message. There it is
Tom Livermore Kitfox S7 SupersportB64B5B5F-8A87-4A99-9E7E-476830466EBE.jpg

[Dave S]

Tom,

At first thought - it looks like some sort of agressive solvent dripped on the surface. What makes me think something dripped n the top is the tapes look to be unaffected/not lifted.

Probably only two possibilities - something either dripped on the top or soaked up from underneath.

Questions - 1) Polytone or aerothane?
2) Is this directly over the tank top or off to the side of the tank over the wing void?

BTW - looks like you did a good job on the tapes - the pinked edges are stuck down well like they should be.

[Tomfox]

It is poly tone/ poly brush etc.

There are several spots. Some are right at the tank edges ( picture is at the rear edge of the tank), but then there are some spots in away from the edge toward the tank center. It is only the right wing.
There are some edge spots up the sides of the tank also. It is only in the tank area, not over the wing void.

My first attempt at repair will be to wipe spots clean down to fabric with with MEK , then redo all coats including silver of course. Comments?

is it possible that I did not put adequate poly brush on before fabric and this is the tank bonding glue doing this? Your comment on top down attack would negate this - good thought though.
or perhaps I spilled a lot of fuel (I use auto gas and 100LL) and it got trapped and caused this?

Thanks
Tom

[Dave S]

It is poly tone/ poly brush etc.

My first attempt at repair will be to wipe spots clean down to fabric with with MEK , then redo all coats including silver of course. Comments?

is it possible that I did not put adequate poly brush on before fabric and this is the tank bonding glue doing this?
Tom

Tom,

I think your approach to the repair is perfect. One of the beauties of having polytone is the ability to do this on a spot repair. It is apparent you have studied the Poly Fiber manual well.

The process of dissolving off the top coat and intermediate coats may reveal what is going on if it is coming from underneath (or not). Also possible that the cause might not be apparent either. If it looks good underneath - should be fine with the repair.

The fact that only one wing is affected might indicate that the tank bonding glue might not be the source - the stuff cures pretty well in a fairly short amount of time.

After your repair, one of two things should happen - either it will be stable and remain as it should (which is what a person wants) or the problem may repeat itself (hopefully this won't happen).

Wishing you good luck with the repair.