Should you see glass weave under 3 coats epoxy?

The subject says it all. After filling the weave with 3 coats of epoxy I can, in places distinctly see the weave. I haven't yet sanded. Is this normal?

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RE: Should you see glass weave under 3 coats epoxy?

If you haven't sanded at all then yes, you may be able to 'see' the weave under certain lighting conditions. Adding coats of epoxy beyond the first one that saturates the fibers simply adds another layer to all the textures of weave, high and low. Epoxy's not self-leveling to any great degree.

Much depends on your methods of epoxy application too; roller vs. squeegee vs. the closed-cell packing foam cut into pads I learned about from a Forumite on the WoodenBoat forum. Rollers will add a texture of their own, plastic squeegees may not leave enough epoxy on the high spots if you use too much pressure, the foam pads are supple at the edges & allow easy control of a puddle of epoxy yet leave a very smooth texture over everything once you're done.

Frequently you can still 'see' light refractions from fiberglass fabric's fibers through a number of coats of epoxy while the actual texture they can impart is all but undetectable by touch or sight, a frustration to those aiming for a truly "bright" furniture-like finished appearance.

Sanding between coats takes off the high spots. They'll get more epoxy with the next coating, the valleys in between get more.

RE: Should you see glass weave under 3 coats epoxy?

Just to add one note to spclark's explanation - if the glass is not properly saturated you'll see translucent whitish weave at certain angles. If the saturation is really bad, you'll see white weave at all angles. Sanding and more coats of epoxy do not help. The only way to fix either of these is by removing the glass and re-applying new. Hope that's not what you have.



RE: Should you see glass weave under 3 coats epoxy?

   Thanks clark and laszlo.

What i'm seeing isn't white. It's just the pattern itself, and not from ALL angles but seems like from most. 

Saturation was done with squeegee and all glass went clear, absolutely no white. Following three coats were applied with squeegee to spread and then roller to even out. These fill coats were all applied 6-10 hours between each other with no sanding in between. 

I now have a surface with no glass texture but I have not sanded smooth yet. 

This is only my second boat and I haven't glassed anything in a while so I can't remember exactly what it looks like. On my first boat I have noticed places where, in certain sunlight, I can see weave beneath epoxy and varnish and have assumed it being the first boat, I just didn't do something right. So on this boat, I've spent a good bit of time reading about glassing and assumed (maybe wrongly) that I wouldn't see the weave. I keep reading about it 'disappearing' so I think that's what has me questioning my work. 

RE: Should you see glass weave under 3 coats epoxy?

Novice here.  Just want to echo spclark's advice above (through my experience) that using a squeegee with too much pressure may not leave enough epoxy.

I fiberglassed my first kayak not long ago (and used a squeegee with/without first using a roller for every coat because that seemed to be the only way I could put it down without lots of bubbles).

I sanded (gently) after the 2nd coat of epoxy, thinking I would see things flatten out after the 3rd coat.  I still saw the weave all over after the 3rd/4th coats and decided to sand.  I ended up breaking through to wood at a chine and realized I really was putting it on way too thin, so I added another couple of coats to seal things up again.

I really feel like a squeegee is still the best way to go (probably after spreading via a roller), but I will try to use less pressure / more tilt and/or wait until the epoxy has become a bit more viscous before squeegeeing it if/when I build another boat.


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