Hull blisters

[mestrezat]

Every time I haul out for another hull painting, I find lots of osmotic blisters in the hull. I’ve ground out, punctured, filled fared, sealed and painted over. The next day, more seem to show up. At the next haul out, more surface. I’ve done this over and over. We are now hauled out in Puerto Penasco at the north tip of the Sea of Cortez and are considering micro planing the hull, letting it air dry and then faring,sealing and starting over.
Is all that work really necessary? I know the blisters look unsightly but I don’t think they will sink a boat. Ours was built in 1982 and has allowed us to circumnavigate the planet with no problems(at least with the hull). Should I just leave them alone, continue what I’ve been doing or go the micro planing. We