I applied a layer of glass to both sides of a paddle I made. In some areas, there is too much epoxy, while in other areas the weave is not fully covered.
When I’m finishing drywall, I don’t sand until after the skim (third) coating. Coats number 2 and 3 fill in low spots.
Should I work fiberglass the same way? Fill first, then sand at the end? Or should I be sanding between coats of epoxy?
I’m using West System epoxy, and I know that means I need to wash off the amine between coats. The epoxy and fiberglass only run part way up the shaft, and above that I have unfinished wood. Can anyone advise a trick to keep water off the raw wood when I wash?
TIA,
~~Chip
If you sand to early
you’ll fuzz the glass and spend extra time filling and sanding. Put a couple coats of epoxy on first then sand. You’ll be ahead of the game.
No need to keep unfinished wood dry.
I mean I wouldn’t leave it in a tub of water over night, but I wouldn’t worry about getting it a little wet from washing off the blush. Sure, if it gets wet it’ll raise the grain some but, when it dries just give it a quick going over with 220 or wait until the resin-sanding stage since you’re gonna varnish the whole thing anyway.
Fill first
In many books they recommend to put down a layer of epoxy first to help seal the wood. cure then glass. Although I never sacrificed the weight I tend to agree since wood will absorb the epoxy at different rates, sometimes sucking out the epoxy from under the glass. As for the grain swelling if you get the unfinished wood wet, not an issue.
Sand off as much excess epoxy
as you can before adding any more. If you touch the glass with the sandpaper in a few spots, it’s no big deal. The 2nd or even 3rd coat of epoxy will take care of the problem. Just be careful not to sand heavily into the cloth.
Marc Ornstein
Dogpaddle Canoe Works
Custom Paddles and Cedar Strip Canoes