epoxy sealing water in haul??

[man5]

Grinding woven roving for stringer replacement. foam that was torn out was wet. looks as though roving was put down sloppy. as I'm grinding to rough the surface up I am finding air pockets, some with water in them. Should I grind all the roving out? Otherwise it seems as though the water will get trapped in there and or cause delamination. wanted to use epoxy for repairs.

[marshmat]

The wet foam, I presume, was originally the core of the stringer?
Pockets of air and water are not a good sign. If a bubble is left in place, loads that would normally be spread out over the whole region become concentrated in a small ring at the edge of the bubble. The glass then peels a bit more, the bubble gets bigger, and so on. If they fill with water, the deterioration is accelerated- especially if the boat is stored below freezing in the winter. I suspect you will have to remove the roving over the bubbles and clean them up before you can rebuild the stringers. Definitely use a good epoxy- and make sure the surfaces are clean and prepared with the proper solvents. With due care in the rebuilding process, bubbles and voids can usually be patched, but it takes a long time- patience is definitely helpful.

[man5]

Sorry I meant to say the flotation foam was wet.