Fiberglass Question

A couple weeks back I found some spots inside my hatches where the fiberglass was getting fuzzy for lack of a better word. I was doing some other fiberglass work this weekend and decided I would try to re-coat the areas with resin to see if I could make them smooth again. I checked the progress this morning and instead of find a nice smooth surface I now had a rough hard surface instead of the relatively soft fuzzy surface.

What should I do next to smooth it out? I’m guessing I need to sand it down, but do I apply more resin after sanding or just sand as leave as is?

i’d sand again
If you want that super smooth finish, i’d sand once more and brush on another coat of epoxy.

I’m concerned
that you may be dealing with Kevlar and not fiberglass. If it is Kevlar, sanding will only create more fuzz.

If the fibers have a golden color, then you are dealing with Kevlar. Don’t sand. it will only make things worse. Trim off any loose fibers as best you can with a brand new single edge razor blade and recoat with more epoxy. It may take several coats. Once you’ve built some film thickness with the epoxy, you can sand lightly, as long as you don’t cut down through to the Kevlar.

If indeed the boat is fiberglass, disregard the above. Sand as necessary, working your way through the grits from 120, - 220, -400, -600, -1200, and finally rubbing compound to bring back the gloss. If you don’t care about the gloss, #220 grit paper is about as far as you need to go.

Marc Ornstein

Dogpaddle Canoe Works

Custom Canoe Paddles and Woodstrip Canoes


Definitely Fiberglass
The boat is definitely fiberglass. If it was Kevlar it would be the heaviest Kevlar boat ever! :slight_smile:

Thanks for the advice looks like I’ve got some sanding in my future.

What I do, and it comes out as smooth.
as glass.

Sand it again to get any of the rough stuff and high stuff off, and sand around the edges.

Then brush another coat of epoxy over that. Then immediately tape a piece of plastic, (like overhead projector film, or equal) over the soft epoxy. let it sit, and the next day when you peel it off you have a glass like finish.

You don’t have to worry about the plastic film sticking. It won’t.

If you had done this the first time. you wouldn’t have to do it again.

It works for me on kevlar too.

jack L

Jack L

Next time use saran wrap
next time you do this coat the repair with a piece of plastic wrap and stretch it out and tape it down with masking tape. when the repair dries it will be smooth and silky and no sanding unless you made a bubble or valley or are very very picky.


If it’s kevlar wet sand it 220 grit, repeat if required.

I think it’s good if repairing Kevlar hull fibers bond into new epoxy.

Actually, the best tool for shaping/smoothing with Kevlar is a carbide paint scraper, as it doesn’t cause fuzzing.

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