Blister informatin.
 

Blisters on fiberglass yachts are sort of like Bobsprit.
They show up only after the work has been done.

Extensive study on blisters has shown the following:

a.. It is not possible to effectively solve the blistering problem of a hull that is water permeable.
b.. Water permeability of a laminate is not the function of a resin alone, but how well the glass fibers are saturated or wetted
out with resin. If a hull is permeable from the outside, its also permeable from the inside. What is the point of recoating the
outside when the inside is also exposed to water?
c.. Blistering on above the waterline structures proves that immersion is not necessary to cause blisters.
d.. We learned from the Uniflite class action suit in the early 1980's that continuous strands of glass fiber are capable of
conducting water along their entire length by means of the capillary effect. For example, if a roll of roving is laid out from one
end of the hull to the other, and the wet out is not good or complete, those fibers can wick water along the entire length of the
sheet of glass.
e.. We also learned that engine vibration transmitted to the hull is one of the major means by which water is transmitted through
unsaturated strands. Capillary effect alone is not responsible.
f.. In a four year casual study that involved examining every hull that I ran across that had the outer coatings removed
(involving hundreds of boats), the lack of complete wet out was appallingly bad in well over 50% of all boats that I looked at.
There is a direct correlation between low quality resins and poor wet out on blistering.
g.. The use of chopped strand mat as a skinout layer to prevent telegraphing of weave patterns through the gelcoat is a major
source of the problem of water absorption of the hull. This is because mat does not wet out well. Further, because the fibers are
short, there are millions more exposed ends of fiber bundles capable of wicking and conducting water through the laminate. Heavy
layers of mat are very hard to fully saturate with resin. It is also responsible for causing millions of small voids that ultimately
fill with water. Its almost like a wood boat that has millions of tiny worm holes.
h.. Exposed fibers on the inside of the hull are also responsible for wicking water into the laminate. There is a definite
correlation between where blisters most commonly occur and where bilge water lays within a hull. There is also a correlation of the
predominance of blisters and the edges of sheets of glass fabric.
i.. Major blistering problems are often related to bonding failures of both gelcoats and skin out mats. I was not aware of this
until about a year ago, when, one day, I watched a blister repair contractor stripping the gelcoat from a hull. Not only was the
gelcoat coming off, but the entire skin out mat was peeling off (see actual photo of this boat). On closer examination I found that
major areas of the skin out mat had never achieved bonding and could be peeled off by hand. As I continue to examine boats for this
condition, I am finding more and more of them.
j.. Examining the process that yards use to remove the blisters, it is found that most keep grinding away until they stop seeing
any evidence of delamination. The problem that they often run into is that the delamination never stops. The nearby photos reveals
some of the conditions I have found in the vast majority of all blisters that I have examined (thousands). That is that most
blisters involve ply separations that seemingly never ends. They grind and grind and grind, but there's always separation around the
circumference of the blister.
k.. When ply separations or incomplete bonding exists, blistering is a problem that cannot be solved. That's because the void
areas are going to fill up with water all over the bottom. Repair the blisters and they will reappear because its not possible to
keep water out of a hull that's constantly immersed in water.

I think the above is good information. I particularly like the
part where it says engine vibration is a major cause of wicking
and blistering. All you diesel lovers take heed. I've seen boats
with big inboard diesels literally shake all over.

S.Simon

references: http://www.yachtsurvey.com/moreonblisters.html.htm

Blister informatin.
 

If a hull is permeable from the outside, its also permeable from the inside.

False. It is only permeable to a point where it is retarded by resin
saturation.

RB

Blister informatin.
 

d.. We learned from the Uniflite class action suit in the early 1980's that
continuous strands of glass fiber are capable of
conducting water along their entire length by means of the capillary effect.

False and misleading. Capable only, but not likely.

RB

Blister informatin.
 

"Bobsprit" wrote in message
...
If a hull is permeable from the outside, its also permeable from the
inside.

False. It is only permeable to a point where it is retarded by resin
saturation.

Thanks Bob! Yet another post that I was able to put straight onto the
roses. They burst into flower instantly.

Where do you get this sh*t from?



Regards


Donal
--

Blister informatin.
 

False. It is only permeable to a point where it is retarded by resin
saturation.

Thanks Bob! Yet another post that I was able to put straight onto the
roses. They burst into flower instantly.

Donal, FG blistering is not generally uniform, even when lay up is not done
correctly. Since you own a boat renowned for blistering, you'd do well to learn
about it. Only the late 80's Catalina's blister more.

RB

Blister informatin.
 

"Bobsprit" wrote in message
...
False. It is only permeable to a point where it is retarded by resin
saturation.

Thanks Bob! Yet another post that I was able to put straight onto the
roses. They burst into flower instantly.

Donal, FG blistering is not generally uniform, even when lay up is not
done
correctly. Since you own a boat renowned for blistering,

At what age do they start to blister? Should I sell her immediately?


Regards


Donal
--

Blister informatin.
 

At what age do they start to blister? Should I sell her immediately?

Some boats can develope blisters at the waterline within a few years or sooner.
There was a run of Valiant yachts that had this problem reported within a year
of production. If you have blisters they will be small, as in the Jeaneau
problems a few years back. Of course that was thanks to Beneteau taking over!

RB

Blister informatin.
 

Great post.

Here in Mobile, AL where boats stay in the water year-round blistering is a
problem.

My Peason Flyer just purchased from Connecticut had zero bottom blisters but
was covered in blisters at the trailer pads from sitting on the trailer for
4+ years. The carpet on the pads never dried out.

I used a black water barrier / coal-tar type product on my last Flyer and
that stopped all the blistering. Water could not get past it to the
gel-coat.

Dennis

Blister informatin.
 

Dennis Vogel wrote:


Here in Mobile, AL where boats stay in the water year-round blistering is a
problem.

Yep, blistering is worse in warm climates.


My Peason Flyer just purchased from Connecticut had zero bottom blisters but
was covered in blisters at the trailer pads from sitting on the trailer for
4+ years. The carpet on the pads never dried out.

I used a black water barrier / coal-tar type product on my last Flyer and
that stopped all the blistering. Water could not get past it to the
gel-coat.

If you're going to put on a barrier coat, then it's smart to take the gel coat
off. All the gel coat is, is a quick & cheap attempt to seal the fiberglass
laminate. The fact that polyester resin is permeable to water, no matter how
much wax you dissolve in it, makes it only marginally effective. No point in
leaving it on there. Plus it makes the barrier coat more likely to flake & peel.

Fresh Breezes- Doug King

Blister informatin.
 

On 26 Oct 2003 23:58:58 GMT, (Bobsprit) wrote:

At what age do they start to blister? Should I sell her immediately?

Some boats can develope blisters at the waterline within a few years or sooner.
There was a run of Valiant yachts that had this problem reported within a year
of production. If you have blisters they will be small, as in the Jeaneau
problems a few years back. Of course that was thanks to Beneteau taking over!

RB

The Valiant problems were all due to the fire retardant resin that was
used. The resulting problems were severe enough that "old Valiant"
was bankrupted and sold. That fire retardant resin caused blistering
above and below the water line. That was a little different situation
than the osmotic blistering you are discussing which is encountered on
many/most boats in some numbers to some degree. My old C&C had some
blistering. It isn't the end of the world.

Blister informatin.
 

My old C&C had some
blistering. It isn't the end of the world.

Nope. Rare that the damage is bad, but best to catch it early, especially on
the Beneteau.
Good info on Valiant...thanks.

RB

Blister informatin.
 

The problems were isolated to those
particular hulls, but the "blister boat" label really hurts the value
of those (specific) old Valiants. No problems before or after. Great
boats.

I think I read in Sailing about those "bad years" and Valiants, now corrected
and protected that can still be had for cheap.
Not a bad way to get a serious cruiser.

RB

Blister informatin.
 

"Simple Simon" wrote in message ...
Blisters on fiberglass yachts are sort of like Bobsprit.
They show up only after the work has been done.

Extensive study on blisters has shown the following:

Fiberglass boats blister !

S.Simon

references: http://www.yachtsurvey.com/moreonblisters.html.htm



Just show how inferior a fiberglass boats is compared to steel.
Real Sailors use steel!

Joe
MSV RedCloud- Made of only the finest English Steel & Monel!

Blister informatin.
 

Isn't steel another set of problems all together?
"Joe" wrote in message
om...
"Simple Simon" wrote in message
...
Blisters on fiberglass yachts are sort of like Bobsprit.
They show up only after the work has been done.

Extensive study on blisters has shown the following:

Fiberglass boats blister !

S.Simon

references: http://www.yachtsurvey.com/moreonblisters.html.htm



Just show how inferior a fiberglass boats is compared to steel.
Real Sailors use steel!

Joe
MSV RedCloud- Made of only the finest English Steel & Monel!