[C320-list] Question abouts Blisters on Early Models

[Allan Field]

Hi Tony - I owned a 1981 Ericson many years ago that severely blistered.
The hull layup was with polyester resin. My limited understanding is that
water always is going to migrate through a hull (unless there is a barrier
coat under the paint) through osmosis. With the polyester resins, the water
and the resin mix to create an acid that then eats its way back out.
Catalina has been using vinylester resin for many years and I have not
heard of blisters with vinylester. However, there was a run of C320's where
vinylester was not used and some of those did eventually blister. And I
don't know when Catalina started using vinylester. With hull #30, it is
possible that vinylester came later. My memory, and maybe the Association
archives could speak to this better, is that about 150 or so C320's in the
300-500 series had problems.

All that said, a couple things to think about. First, make sure what you
are seeing isn't just paint blisters. Many dealers did poor (or no!) jobs
of dewaxing hulls before applying bottom paint for the first time which
leads to paint blisters, something that never is going to go away until a
thorough paint peel and dewaxing is done. Second is that if you opt for the
peel down of the hull, the boat needs to dry out first. This is a lengthy
process for the drying out and as you note, the peel down is not cheap. On
my Ericson, it was so badly blistered that I opted for the peel down, the
boat was out of commission for almost a year, and the cost in 1990 was
$8500 with one quote coming in at $12,500! Third, no boat has ever sunk due
to blistering, at least to my knowledge. So I am not too entirely sure how
big of a problem blistering is other than cosmetically... Fourth, you may
want to start with some research on grinding down blisters first and then
refilling where you ground down. There are many articles out there on how
to do this. If you only have a few blisters, this may be the way to go.

Finally, I am on my second Catalina. I had the 320 #808 for 16 years, it
stayed in the water all year round on the Chesapeake Bay, and came out
every 2 years for about a week to lightly sand the hull, apply new ablative
paint, and take care of the underwater metals. On the off-year, I had a
diver change the zinc. Same routine with the Catalina 387 that we now own
except that the previous owner did put a barrier coat on at transfer of
ownership.

Hope all this helps!

Allan S. Field
Sea Shadow - C387, #103
Columbia, MD

On Sun, Jun 14, 2020 at 12:07 PM <amshd2 at aol.com> wrote:

> All
> I have a earley model 320 a 94 Hull # 30.  She stay in the water and comes
> out every 2 years for new bottom paint.
> Last uear she came out and we found a couple of blisters.  This winter she
> came out for some unscheduled maintenance and we found 3 more blisters.  A
> moisture mter should a evelated level of mositure throughout the hull and
> the yard recommened a full peeling.
> Up until now I never heard of a peeling. From what I have learned so far
> it sounds like it takes the hull down to the fiberglass.  Thus allows the
> glass to dry and then put down a new barrier coat.
> It is not a cheap process.
> Has anyone had this done?    Thanks ahead of time
> Tony
>
>