[C320-list] 7" Hull Blister

[Doug Treff]

Brian,

My advice to you is find another fiberglass guy. If he doesn't know this
is a "void" and why they happen, he isn't qualified to do this repair.
Voids are made when the layers of fiberglass matting are not fully
wetted out with resin during construction. Over time, the layers will
let go and delaminate, causing a void in the hull structure. He is
correct that the "proper" repair requires opening up the void. The
poorly wetted mat will need to be removed down to solid fiberglass and
then you will need to lay new glass mat to build up the thickness,
followed by re-application of Gelcoat to blend in the repair. Ted
Harrison made a good suggestion that the boat could be tented off and
the environment controlled with heaters. However, this will be very
labor intensive and costly. Here is a link to an article on a proper
void repair:
http://newenglandboating.com/channels/how-to-repair-a-damaged-hull.html

Allan correctly identified this as a void but I don't believe there is a
liner in this part of the hull. The area you described seems like it
would be in the aft lazarette, and on my vintage of C320, there is no
liner in that compartment. I also second Allan's suggestion that you
should engage with Catalina for recommendations before you allow that
resin injection repair to be done. If Catalina had an issue in the
perfect environment of the factory getting the mat properly wetted out,
what makes you think that a field repair with a couple of feeble holes
and a tube of resin will really fix anything? Last time I called them
with a question about fiberglass layup, I received a return call from
Gerry Douglas himself. Fantastic customer service if you ask me.

How long have you had the boat, and did you have a survey when you
purchased her? Surprised this did not come up in your survey.

--
Doug Treff
September Song - #350
doug at treff.us

On Wed, Nov 2, 2016, at 06:48 PM, Amiraults Family wrote:

> This was close-the-boat-for-winter-day. Thanks to the orientation of the
> hull and position of sun in sky, I made first note of a hull gel coat
> blister located just aft and above the exhaust port. It is round, 7" in
> diameter, and certainly sounds out as a void. This area is above the
> waterline and neither I nor the local fiberglass guy has an explanation
> for
> why it would happen.