On Sun, 01 May 2011 08:01:40 -0600, slide
wrote:

On 4/30/2011 3:18 AM, Bruce in Bangkok wrote:


You really don't get it, do you.


As usual, Bruce is correct. Here's a well done analysis of the issue:

http://www.zahnisers.com/repair/blister/blister1.htm

I missed many of these posts about "osmosis" and Skip spraying water
on the hull, but early on read that article - and others.
Concluded that Neal didn't understand the type of osmosis taking
place, and that Skip is doing more harm than good in spraying his
bottom.
Any reading of the above article and others says you want to avoid
causing more hydrolysis of the laminate.
For example, older boats have more porous gel coats and no blistering,
but suffer from severe deep delamiination.
As I recall, Skip mentioned the spraying "washes out the acids" or
something to that effect.
But to get those acids out by more absorption of water he's weakening
the laminate.
You'll note in the above article the suggested repair is new outer
laminate. That's an expensive proposition.
But an alternate handling of blisters is to just grind them off, let
the hull dry, epoxy the blisters properly, then barrier coat.
Further hydrolysis will get blisters back again, but that can't be
helped.
There's no way to read that article and think otherwise.
Gee, I wish I had a boat to worry about.

--Vic