did kinda the same thing with ours. Discovered the DPO (dread previous owner) had started and lost interest in a bottom job. Sanded through the gel coat then simply painted on anti foul. Couldn't tell when we bought it.

Soda blaster dude calls me after he got about 2' into it and asked if I was gonna peel it. "huh?" says I

Then he described the entire bottom covered in blisters about the size of a match head. Offered to either stop and just charge me $50 for his setup time or "I can crank up the pressure and blow them open, but you'll have to fix it" Honest guy, didn't want me to waste my money if it was destined to get peeled.

I took option 2. The entire bottom looked like a golf ball. SG saw it in the yard.

Dremeled out the hundred or so that the blaster didn't get and let it dry over the winter.

Washed it down with acetone and MEK to remove and oil/piant/blister acid residue and basically plastered it with continuous coat of 2 part System III epoxy putty. Awesome stuff, super easy to work with!. Faired it, barrier coated and painted as you described. Looks beautiful 6 years on.

So we finished and she's hanging in the slings ready to drop The yard manager puts his arm around my shoulder and said "You know, you didn't F### that up"

"What?" I said

"Most people get half way through that kinda thing and give up. Either slap paint on it or hire it out. You stuck with it, looks good"

LMAO that's like a kiss on the lips this guy.