Polyfiber wrinkles

[JoeRuscito]

I just noticed this wrinkle in my paint. At first I thought I had dripped brake fluid or something but it is dry on both sides of the fabric and I don't believe I ever dripped anything. Has anyone seen this before? Its on the bottom of my fuselage in the middle above the seat legs. I looked the plane over but didn't see it anywhere else.

Thanks! 2299222993

[JoeRuscito]

I think Ive answered my own question. I noticed there was some heat shrink directly above the spot, where I had added chafe sleeve to my brake lines.... well I must have gotten a bit too close with the heat gun without thinking. Pretty frustrated with myself that I didn't think about the fabric. It seems like the fabric is still strong I pushed and prodded it quite a bit. The paint and coatings still seem well secured. Should I be concerned about the fabric strength? In this spot I would think it should be ok.

[rawheels]

You could cut it out and add a patch if you feel the degraded fabric is in a flight-critical spot. It is really pretty easy with the poly-fiber system, just follow their directions in the book.

[JoeRuscito]

I don’t believe it’s flight critical. It’s right above the gear. Center of floor of the fuselage. Maybe only 2x2 absolute max area that would have gotten any heat.

[Dave S]

Joe,

If the fabric still has its tension as you indicated, I'd suspect the there is no integrity issue with that. The paint likely softened a bit from the heat and that may be why there are some things that look like sags. If the paint ever peels - not a big deal to repaint the spot.

If the fabric were REALLY overheated - it would start to lose it's tension and you would be able to detect that. If it is not flapping in the wind - I don't see a problem.

FWIW - I did what could be called a boo boo on the belly fabric - dropped a phillips screwdriver point down punching a perfectly round hole - so I slapped a grommet on it and called it a "Drain hole" :o

We all have some kind of imperfection somewhere on our planes - the belly out of sight is the perfect place.

Fly Well

[JoeRuscito]

Thanks Dave, I was definitely kicking myself when I figured it out.... Couldn't be happier with the placement of said mistake though... hard to see at all.

[jiott]

I learned something to avoid. After all was painted with Aerothane, I added a small doily on the INSIDE of the fabric (on the belly luckily) to reinforce an area where I had punched thru the fabric to install an OAT sensor. The MEK in the PolyTak I used to glue down the doily softened and bubbled up the paint on the outside of the fabric. Had to remove the bubbled paint and redo.

[JoeRuscito]

Oh man good to know! The aerothane looks awesome.... But I do not want to repair it if I can avoid!

Thanks for the tip

[109JB]

Punch test that area. If it fails, fix it. If it doesn't you are good. Speculation doesn't work.

[Ronin]

I just noticed this wrinkle in my paint. At first I thought I had dripped brake fluid or something but it is dry on both sides of the fabric and I don't believe I ever dripped anything. Has anyone seen this before? Its on the bottom of my fuselage in the middle above the seat legs. I looked the plane over but didn't see it anywhere else.

Thanks! 2299222993
You could try heating it (from the outside) slightly, maybe test a small corner. Nothing to lose at this point.

[Delta Whisky]

I'm with 109JB.