On Tue, 03 Jan 2006 11:41:23 -0500, Wayne.B wrote:

On Tue, 03 Jan 2006 06:30:51 -0500, Harry Krause
wrote:

Since the water buildup probably occurred over a long
period of time via osmosis through tiny pores in the glass gelcoat,
wouldn't a rapid dissipation of the water be impossible through those
same pores? Would you not end up just "deskinning" the boat, as it
were...popping off the gel coat?

That is probably a very real concern in my opinion. Turning water
into steam can create some very high pressures if entrapped.

The best cure is simply not to buy a boat with an osmotic blister
problem. I know this flies in the face of the advice of boat salesmen,
owners of boats, and others with a stake in the used boat business, but
better osmotic acne remain *their* problem, and not yours.

Easy to say but the real world is different if you own an older boat.
Boats that have never blistered in the past can suddenly develop a
crop if conditions change, e.g., water temperature, length of season,
etc. On a boat over 4 or 5 years old you really have no recourse with
the manufacturer.

Does this happen mostly to boats that are in slips? Are those removed from the water
after each use subject to this blistering?

--
John H.

"Divide each difficulty into as many parts as is feasible and necessary to resolve it."
Rene Descartes

On 2 Jan 2006 19:44:19 -0800, "
wrote:

NOW I see. OK, maybe we should simply eliminate all such deductions.

Google Groups is being very balky tonite.

Thanks guy!

--
John H.

"Divide each difficulty into as many parts as is feasible and necessary to resolve it."
Rene Descartes

wrote in message
oups.com...

JIMinFL wrote:
My thinking is backward from yours, Chuck. I think of the gel coat as the
layer that is supposed to be waterproof. The laminate may or may not be
waterproof depending on how well the layers are saturated with resin. I'm
sure if you scrape the gelcoat off something like a BayRay or other mass
produced boat, you will have a leak.
JIMinFL

I don't always agree with David Pascoe on some issues, but I think he
has written one of the most informative and easily understood essays on
blisters and how they affect a boat.
If you check out the illustrations and explanation at this link, you
might amend your opinion about gelcoat preventing leaks in a fiberglass
hull


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

I read his essay and I don't think that I said anything that needs to be
amended.
Pascoe did say that both the gelcoat and roving/mat are porous. I don't know
if this is true of modern resins but the older boats made of polyester resin
were somewhat porous. But not to the point that you would notice significant
accumulation of sea water in the bilge. I had an old Reinell once that
leaked about 2 quarts a day. It wasn't coming from the engine room nor way
forward. It had to be coming from under the cabin sole. I cut an inspection
port into the sole and found a spot where water was oozing in drop by drop
right at the center of the keel. I didn't see any cracking so I decided to
leave it as is until haulout time. After removing several coats of bottom
paint I found that the gel coat had been worn off . Probably from repeated
beachings at one time. My fix for that was a few layers of cloth and epoxy.

I would not let any crack or gouge in gelcoat go unrepaired. Particularly
under the water line.

JIMinFL wrote:


I would not let any crack or gouge in gelcoat go unrepaired. Particularly
under the water line.

I think we would agree on that. Particularly since it's almost
impossible to crack or gouge *only* the gel coat. :-)

Your experience with the leaking keel is a good example. After several
groundings, you noticed some water seeping into the bilge through the
keelson. The couple of layers and cloth you applied for a fix went well
beyond a simple gelcoat repair.

I think you could strip all the gelcoat entirely off a boat and it
would still float. If the fibers were adequately wetted out with resin,
the hull wouldn't even absorb water (or "wick" it around). That seems
to be where we disagree.

As you know, there are some premium manufacturers who don't even use
gelcoat on their fiberglass boats. If the mold is perfect enough, one
can get by with paint rather than gelcoat. Gelcoat is an easy
workaround for imperfectly finished molds, as it tends to hide various
sins while paint tends to magnify them.

" wrote:
I may have talked about this idea before but it was inspired when I was
doing blister repairs on a boat and used a heat gun. The heat gun
literally drove water from the hull and it poured out of adjacent
blisters so...........Why waste time heating the glass when you really
want to heat the water and other polar molecules.


Water is non-polar

Wayne.B wrote:
What are the other heating possibilities other than microwaves that
require shielding? Magnetic resonance device or something similar?


That'd work. So would a laser.

I wonder if playing really awful music, very loud, would
drive blisters away? Would that work better if the speakers
were inside the boat or outside?

DSK

wrote in message
oups.com...
Your experience with the leaking keel is a good example. After several
groundings, you noticed some water seeping into the bilge through the
keelson. The couple of layers and cloth you applied for a fix went well
beyond a simple gelcoat repair.

That isn't exactly what I said, but after removing the bottom paint, the
area sans gel coat was smooth and I didn't know if any of the laminations
had worn off. Being a belt and suspenders kind of guy, I chose to build the
area up a little. I probably could have gotten by painting the spot with
epoxy.





I think you could strip all the gelcoat entirely off a boat and it
would still float. If the fibers were adequately wetted out with resin,
the hull wouldn't even absorb water (or "wick" it around). That seems
to be where we disagree.

Now you are qualifing with "adequately wetted out with resin". Sure some
better hulls will be more resistant to water penetration. The cheaper hulls
still depend on the gel coat to keep the water out.

30. JIMinFL



I think you could strip all the gelcoat entirely off a boat and it
would still float. If the fibers were adequately wetted out with resin,
the hull wouldn't even absorb water (or "wick" it around). That seems
to be where we disagree.



Now you are qualifing with "adequately wetted out with resin". Sure
some
better hulls will be more resistant to water penetration. The cheaper
hulls
still depend on the gel coat to keep the water out

******

:-)

When one states that water is going to leak through the frp laminate
and into the boat unless it is somehow stopped by the gelcoat- and if
one means "if the hull is defective.......", then it would be best to
so state. When talking about general functions of gelcoat, laminate,
etc it would be customary to assume one is talking about a standard
hull rather than a defective one.

No builder depends on gelcoat to keep water from leaking into the
bilge.

"Harry Krause" wrote in message
...
wrote:
JIMinFL wrote:

I would not let any crack or gouge in gelcoat go unrepaired.
Particularly
under the water line.

I think we would agree on that. Particularly since it's almost
impossible to crack or gouge *only* the gel coat. :-)

Not true.

Cracking is one thing. Gel coat can (and will) crack easily. Gouging is
another issue, given than most gel coat applications is thinner than a dime.
Making it thicker is no good as it will tend to crack more.

Eisboch

"JohnH" wrote in message
...
On Mon, 2 Jan 2006 22:28:17 -0500, " JimH" jimh_osudad@yahooDOTcom
wrote:


wrote in message
groups.com...
I may have talked about this idea before.........

Here is an idea. Why not address questions presented to you in other
threads you started before starting yet another new thread?


Jim, are you just looking for a fight? My gosh, you posed the question,

"For the rich????????"

Was that really supposed to be more than rhetorical?

You're trying with Harry, now you're trying with dhohara. Why not knock it
off?

Jeeeesh!

--
John H.

"Divide each difficulty into as many parts as is feasible and necessary to
resolve it."
Rene Descartes

Thanks Mom.

BTW: He posed the statement about the deductions being only for the rich.

Have a nice day John.

"Harry Krause" wrote in message
...
JohnH wrote:
On Mon, 2 Jan 2006 22:28:17 -0500, " JimH" jimh_osudad@yahooDOTcom
wrote:

wrote in message
oups.com...
I may have talked about this idea before.........
Here is an idea. Why not address questions presented to you in other
threads you started before starting yet another new thread?

Jim, are you just looking for a fight? My gosh, you posed the question,

"For the rich????????"

Was that really supposed to be more than rhetorical?

You're trying with Harry, now you're trying with dhohara. Why not knock
it off?

Jeeeesh!




You should ask yourself why you facilitate both of these newsgroup
troublemakers.

How absolutely funny.

Look in the mirror lately Krause?