epoxy fillet repair

[scanlin]

New member here. Really appreciate all the build tips on this forum.

I'm working on a fiberglass and epoxy build (because I want to acquire skills I'll need on other projects later).

After sanding my epoxy fillets and applying a thin coat of primer paint I can now see imperfections on the leading edge where the fin meets the airframe that my 56 year old eyes couldn't see before.

In one place there is not enough epoxy, and in another there is a bit too much. I can sand or grind down the one that has a bit too much epoxy, but not sure what to do with the one where there's not enough.

Should I rough up the surface and put another drop of epoxy there, let it dry then sand/sculpt it, or will some other material be easier to work with? I don't need epoxy for strength because these are through the wall fins with internal epoxy dams, so they're plenty strong enough already. Just want the fillets to be aesthetically nice looking. (I'm in the hobby for craftsmanship... I know I'm overbuilding things that don't matter, but trying to get closer to perfect.)

Thanks!

 

[sharkbait]

New member here. Really appreciate all the build tips on this forum.

I'm working on a fiberglass and epoxy build (because I want to acquire skills I'll need on other projects later).

After sanding my epoxy fillets and applying a thin coat of primer paint I can now see imperfections on the leading edge where the fin meets the airframe that my 56 year old eyes couldn't see before.

In one place there is not enough epoxy, and in another there is a bit too much. I can sand or grind down the one that has a bit too much epoxy, but not sure what to do with the one where there's not enough.

Should I rough up the surface and put another drop of epoxy there, let it dry then sand/sculpt it, or will some other material be easier to work with? I don't need epoxy for strength because these are through the wall fins with internal epoxy dams, so they're plenty strong enough already. Just want the fillets to be aesthetically nice looking. (I'm in the hobby for craftsmanship... I know I'm overbuilding things that don't matter, but trying to get closer to perfect.)

Thanks!

Bondo for large defects and spot putty for minor ones

 

[Ryangengler]

^^^ +1 for the spot putty.

 

[prfesser]

For fast-drying, easy-to-sand spot putty you want the one-part stuff, NOT the two-part. The solvent is smelly but if you live where you can take it outside, it's not much of an issue.
This is the stuff. They have it in a much smaller size, but I buy the 1 lb and use some of it to make balsa/wood/spirals filler (add just enough acetone or lacquer thinner for the desired consistency, add a little talcum if desired as additional filler material). Sands in a few hours or less.

Join the club of Oldguys™ that CSS (can't see....stuff....) any more.

Best -- Terry

 

[Hobie1dog]

Bondo spot putty is only $6.00 or so and goes a long way, sands easily, meant to go over many substrates. I strongly advise you to wear goggles when using it as there is only 1 warning on the tube CAUSES EYE IRRITATION. I ended up with swollen eyes and in the doctors office.