Marty,

Any chance of some pictures?

Chances are that light sanding will not open the weave enough to get epoxy to the wood. You'd pretty much have to sand through the glass.

Again, some pictures if you can manage it would help us understand the magnitude of the problem and let intelligently suggest fixes.

Laszlo

Unfortunately, glassing on the inside is done first, and that's harder than glassing the outside.  But there is the bonus that you'll have a little glassing under your belt by the time you glass the outside.  The inside is harder because when you squeegie the glass to spread or minimize the epoxy, you pull the glass out from the corners and seams.  If you've glassed the inside of almost anything that has a seam/corner, you've run up against that problem.  Laszlo's trying to figure out how much air you have trapped.  Filling with epoxy is costly (weight, $$$, and brittleness).  You might need to sand through all of the air spots, fair the edges, and add small patches.  Then sand smooth.  If your glass isn't in contact with your fillets, you're going to lose some strength.  The good news is it's all easy to fix, just takes a little more time.  If you are careful with your fix, your kayak will be as strong as anyone else's, and you'll be the only one who knows.  Good luck.

I don't understand" untreated epoxy" what is that , never heard that phrase before

If it's really bad get a heat gun and use it to peel the tape off. The strength of the joint is greatest when the tape is tight against the wood. Epoxy is heavier than water. You don't want a lot of excess in your hull.