[Vlad]

Last year I did some fiberglass work extending cowl snout for FAB. Somehow a tiny strip of Dacron was buried under epoxy. After sanding looks like everything around the strip is getting removed except that little piece. Should I just sand everything down and lay new micro/epoxy or there is a technique to sand that embedded Dacron strip? It's in tight visible spot and no possible laminations expected.

 

[DanH]

"Tiny" is relative. If the part isn't highly stressed, think of the Dacron as being the same as an air bubble between fiberglass plies. A bubble void has no shear or tensile strength of course, but we accept a few without grief in non-structural parts. An FAB snout is certainly non-structural.

In general, if a bubble is only one or two plies beneath the surface I cut it open and fill it. You can easily cut out that Dacron in two minutes with a die grinder. If is small and will be buried several plies deep, leave it there and glass over it.

 

[Vlad]

Thanks Dan,
I am cutting it open and refilling. Good point about air bubbles.