[C38] Hull blistering - ouch!

[les]

JACE had developed a number of very small blisters over patches on her
bottom when we purchased her.  After speaking to many experts, we
decided to leave them alone.  So from 1997-2008, we watched them, and
there was no change.  Then in 2008 at the haulout for the new bottom
paint, we noticed that they had spread and gotten larger.  At that time,
we checked the options again, to see if anything new had come about.

	After getting the various options checked, the apparent best solution
for our case was to have the bottom peeled and a new bottom put on.  We
used Hull Tech in San Diego.  The peel only had to go one or two layers,
and the glass below that was really solid.  I saw it after the peel and
prep for the new glass and it was smooth and unblemished.  When I saw
the new bottom, it looked OK, but a bit rough in places.  Then I was
told that a "racing bottom" would have cost 50% more.  With all that
said, the bottom is good, the performance doesn't appear to have been
changed at least for our uses, so we are happy and we got a 10 year
warranty on the new bottom.  The boat is going to have bottom paint this
year, shortly, so we can let you know then what we find, and send
photos.

	The general consensus from all the research I did, was that small
infrequent blisters can be fixed by patching, but that in most cases,
unless the mixing of the resins is good, and the coverage of the gelcoat
or other topcoat is totally impervious, it will slow, but not stop the
osmotic process that causes the blisters.  The problem is that
essentially fiberglass is sort of a slow hydrophilic compound,
attracting the water, this causes hydrolysis. There is a good article
here: http://www.zahnisers.com/repair/blister/blister1.htm.  Blisters
are the natural result.  This lead the industry to develop various means
to force the epoxy into the glass mat, such as vacuum bagging.

	From what I have read, all boats at some time develop bottom blisters
to some degree.  Some manufacturers have proven remarkable results, but
even those folks have some blisters.  It is part of the environment.
Sailors put the most expensive thing they own in the most corrosive
environment on earth and love to keep it "ship shape."

	Catalina has a pretty good reputation in this regard, and our boats are
long lived and reliable due to their attention to such things.

	I am sure there are other opinions on what to do.  It is a choice you
will have to make.

Regards,
Les Howell
 
On Mon, 2011-05-02 at 20:56 -0400, Marci Brown wrote:
> I just discovered a few blisters on our hull. Would anyone like to
> share their experiences with this dreaded subject matter?
> 
>  
> 
> Marci J. Brown
> 
> PO Box 520549, Winthrop, MA 02152 USA
> 
> Ph: 757-515-3151 | Email: mb at seafor.us
> 
> 
> 
> Description: marci-bkgrnd-icon
> 
>  
> 
> 
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