Sounds like osmosis. You really should determine if that is the case.I
believe there will be water in the blisters if so. I worked on a C&C with
it using I believe an Intertlux system(was a friends boat). He had had the
hull soda blasted and then using a dremel tool ground out all the blisters.
They were then filled and faired off, ending in sealing the hull. Big job
but now the hull is beautiful. Good Luck Michael



"Gould 0738" wrote in message
...
I'd fix the damage and properly bottom paint. An undesirable job, but
if you don't do it they won't go away nor will they get better.


And if they're between the gelcoat and the skinout mat (as 99% of such
blisters
are)
they are a cosmetic problem only. If you lose a lot of sleep worrying
about how
your boat looks under the waterline, spend a few thousand to fix
them.....but
there is a high probabilty that unless you peel the bottom and relaminate
with
vinylester (which is what the newer Bayliners have used for several years)
any
lesser fix will be temporary, at best.

Osmostic blisters are a separate problem from delamination. Delamination
is
very serious, and could compromise the strength of your hull. What you are
describing sounds like osmotic, gelcoat blistering.

Old wives' tales:

1. Osmotic blisters are the first stage of delamination.

2. Blistering causes the laminates to soak up water until the fiberglass
gets
"waterlogged."

Worst effect of blisters is the resale problem. In the Pacific NW, about
90% of
the FRP boats more than just several years old have a few blisters, most
have
dozens, and some have many more. When these boats are surveyed, the
surveyors
note the presence of the blisters and tap carefully around them to make
sure
there isn't any delamination. 90-some percent of the time, there is not
any
delam and the surveyors categorize the problem as cosmetic/non-structural.

Here's where the fun begins. The buyer will look at the survey and holler,
"Blisters? Well, let me tell you: I'm still going to buy the boat but I
need a
big discount!" The seller will say, "Those blisters have been there for
years
and they're no big deal......"
and the re-negotiations begin.

Most of the buyers who get an additional discount for blisters enjoy the
discount but do *not* spend the money to fix the boat. In a few years,
when
it's their turn to sell the boat, they have done a philosophical 180 and
will
be quick to tell their own prospective buyer that the blisters are
"no big deal, just cosmetic."

Good article on blisters, from a controversial source but I think he has
this
fairly well understood:

http://www.yachtsurvey.com/BuyingBlisterBoat.htm