Pinholes in EPS/Epoxy

I just had an EPS/Epoxy SUP shaped. It is a 2lb EPS double stringer blank and is supposed to be glassed with three layers of 6oz glass on the deck and two layers on the bottom. It has a sanded finish, no gloss coat, and an blue opaque resin tint.

I noticed after looking it over after taking it out in the water that along the rails there are many places were there are pinholes or voids. It also looks like the sanding goes into the weave of the cloth such that you can see the resin is not completely filled into the weave in some places.

I will try to take some photos tonight to add to the post to clarify what I am talking about.

Are these pinholes and the exposed weave something to be concerned about? If so, how do I figure it out and what would be the remedy aside from taking it back to the shaper.

I did a search but did not find anything conclusive to answer my question.

Hi feralseppo -

On a sanded board, the exposed weave is pretty much the norm. Really careful guys who do meticulous lap preps can sometimes get away with no exposed weave but generally, sanders hit the weave somewhere along the laps and often elsewhere. Speed spray or acrylic seal coats can minimize the exposed weave appearance.

On the pin holes, it might be just tiny bubbles in the fill coat - no worries. If they go through to the foam, you might consider a gloss coat or a sealing clear coat in falling temperatures to keep it from taking on water.

To determine if the bubbles go through, apply some soapy water and put the board out in the sun. If those little holes start bubbling, they go through to the foam. Take it back if that’s the case.

Thanks John. I did test some of the holes and did find a leaker yesterday. I took some plastic wrap and placed it over the holes and placed it out in the sun. Water started coming out and you could here it squealing.

I’ve tried jamming suncure epoxy with chopped strand down those little holes, but they just pop out as the foam inside changes temperature. I’m guessing the best thing to do is patch it like a ding.

No worries, after its dry take it out into the sun for 10 mins to raise the temp of the board. Now take it into the garage. As it cools the board will want to suck the epoxy in, instead of push it out as it expands from the heat.

Just put a dab on the end of a toothpick and keep feeding it till it fills, or assumes an equal temp.