I sanded through my fabric HELP

I am building SWS. I put first layer of epoxy down over fiberglass, I sanded through in spots on the bottom and a couple on the sides. What should I do? The spots are about softball size, the problem is the fabric had strings lay out when I scraped the epoxy, also where the fabric meets had high spots, hard to sand to get that smooth without going through.

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RE: I sanded through my fabric HELP

   Sand out and fill with a glass patch and epoxy. Add one or two more coats of epoxy to fill the low spots. When sanding keep moving the sander and only sand the high gloss areas. The duust covered or scratched ares have alreday been sanded enough.

You might even want to start hand sanding or using hand sanding for the spots were the sander can not get into.

RE: I sanded through my fabric HELP

a couple other notes on filling in after sanding through.

you can sand through for three main reasons...

1) you had a fare (smooth hull) and you 'over did it' with the sander and created a depression/sand through.

2) your glass was not sitting tightly on your 'fare surface' (e.g., it was floating/had a bubble in it) and when you sanded it fare you cut through the glass bubble.

3) you had a bubble/bulge in the underlying surface/wood and when you sanded it smooth, you cut into the glass.

you can test the difference between 1 vs (2,3) by taking a stiff but flexible board (spare piece of okoume or a plastic ruler) and bending it over the sand-through area).  if you see a depression/gap bewtween the surface and the ruler you have created a depression and, as george suggested above, just put a new piece of cloth over it, epoxy it, and fare it in.

if the ruler test shows you have a fare surface, and there is still epoxy on the sand-through rough area.....you most likely had accidently floated the glass.   in this case, by hand, carefully sand away some more epoxy to create an ever so slight derpression (don't sand into your veneer...just to it) and now lay new cloth over it and fare it in.

if the ruler test suggest the underlying surface has a bulge in it, how you handle it depends on whether you are trying to do a bright (clear) finish or you expect to paint.  if a bright finish, you will just glass over it and live with the bump.  it may be minimized or made to go away by building up the epoxy around it (a foot to the left and a foot to the right)  and refaring it  (this can hide a 1 to 2 millimeter problems).  if you expect to paint it, just sand it down a bit further (its ok if you sand through the veneer becuase you are painting) and follow the same approach as if you had floated the cloth (previous paragraph).

hope that helps


RE: I sanded through my fabric HELP

Others may differ but I use 150 grit on drips and ridges moving to 220 grit for the field during  this process. I think the 100 grit is too course.. I also alternate between the palm sander and the orbital sander. .....  I also stop frequently and feel with the weak hand to feel progress.   Sharp corners get hand sanding.  

RE: I sanded through my fabric HELP

The frayed fabric is a problem too, it strings out when I scrape epoxy, making it easy to sand through when trying to even it out. Thanks for the replies...Jim

RE: I sanded through my fabric HELP

Scraping?.....if you mean operational damage, yes I understand. Scraping.....if you mean like in wood working, don't do that.  Sand it......


RE: I sanded through my fabric HELP

   I mean scraping the wet epoxy out, the fabric freys and strings out along the edge, makes it hard to sand even

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