Blister questions

I've been a wood boat owner most of my life, and for the past four years own an '81 42' Ocean Yachts sunliner.

So blisters is a newish thing to me, but I have heard of them over the years.
I have seen a few on my boat , not many on my haul outs. Dime to nickel size and have just let them be. They seem to stay the same. I haul out around 1.5 to 2 years intervals. Do my work in a few days and go back in again.

Here are my questions;
1- If left untreated/ fixed will a blister work it's way through the hull?
2- I stay in the water year round, is this a problem? Will it create more or enlarge the blister?
3- How to remove and fix a blister? Just dig/grind it out and fill in with west system?
4- I do have a few under the forward deck seat cushions , but I don't have any leaks there and everything is still solid. The cushions cover them up, which I remove for the winter.

I see with lots of blisters, a peel or sand blast is needed to remove layers of stuff, like resin or actual glass?, I'm not in need of that.

I don't want to do a blast and barrier coat, I'm not keeping the boat to long. They seem to be far and few between. Think I will pop them, grind them out , and dry with a heat gun on low to dry quickly, then fill in interlux water tight epoxy filler. I've always used ablative bottom paints, now I'm using the water base kind which seems to work well.
I was always wondering if a blister could work it's way through the hull? I've never heard of that....

Where are you , on the Sass? Just wondering..

Me too...Must be where I'm at for the winter. I'm in the water for the winter under the shed, you must be up on the hill?

Oops, or the other place south of me on the bay.....

Ok, nice quiet place,and nice shed. Rock Hall Prop straightened out my bronze shaft for me a few years back and did a great job.

Oh yeah ? They are good on 1980's Detroits ? I'm not thrilled with my private guy I use. Getting tired of "Having to keep on him" to get things done right.