blisters

[lucky]

 :shock:Last month I had Lucky Pulled  out for bottom paint.She had 10 quarter size blister.These were the only blisters visable,the hull was smooth when I rubbed it,but when the workmen sanded the hull several small pimple type blisters appeared (40).Marina 1700.00 to repair.Sense hull was smooth before sanding and after I decieded to paint over them.Hull looks good.Will pull next year and see if it was a bad decision.What would you have done?
Al Landry
Lucky #13
C-34

[Lance Jones]

Al,
We pulled Kitty's Cat this year to do the same. It's better to catch these small zits before they become the big ones you mentioned. Every time I have my boat pulled, I sand it down all the way. Sort of like a preventive, but, expensive check. I'm over 50 so I get an annual check that I don't like; but, makes me feel better about the future. Same thing you did. Good move. I pull every 2-3 years.

[pablosgirl]

Hi Lucky,

What work did they do for $1700?  Was that just the blister repair and the bottom paint was on top of that cost.  I have used the Repair and wait and see approach one of my previous boats.  That is just treating the individual blisters with West system epoxy and painting over the hull with a couple of new coats of paint.  That worked well, with only a handful of blisters present at each haul out after being in the water 3-5 years.  This was certainly the low cost approach.

On another Boat I had, a 1988 Hunter 26.5, I pulled the boat just 3 months after the 5 year blister warranty had expired and found a classic example of "boat pox" over the entire hull.  There were literally thousands of blisters on that hull.  I contacted Hunter about and they had the nerve to tell me that all those blisters occurred in the three months after the warranty expired.  So much for customer service.  I ended up grinding the gel-coat off the bottom of the boat myself to save money (worst 36 hours of my life).  The boat then sat out of the water for two months waiting for the hull to dry out enough.  I ended up using the Interlux 1000 + 2000 repair system;  4 coats on the 1000 and 11 coats of the 2000 to build up the hull to the previous level of the gel-coat.  That took a few days of around the clock application of the coats while the epoxy was in its "green" state to get the strongest possible repair.  It paid off in the end, after 15 years, no blisters reoccurred on the hull. 

Catalina makes a good quality hull.  With the small number of blisters that you encountered, a wait and see approach may work,  If the blisters keep reoccurring.  Then in the long run it may be more coast effective to sand all the bottom paint off the hull and apply some barrier coat epoxy before the new bottom paint to keep the blisters from reoccurring.

I was fortunate enough that the PO of our boat applied 4 coats of barrier coat paint before her maiden launch.  So we have not had the blister problem.  On our last haul out a year ago I had all the bottom paint sanded off our hull for $150 (some good things can come from a depressed economy).  The old coats of paint were starting to crack from the thick build up.  I then reapplied 4 coats of barrier coat paint for good measure not being sure on how the sanding affected the previous coats of barrier epoxy before reapplying the new bottom paint.

Paul Shields

[lucky]

The $1700.00 was for blisters only,$1400.00 for sanding and two coats of interlux paint.The boat was stripped ten years ago and inerlux2000 applied along with two coats berrier paint.We don't have a diy yard on texoma,so every thing has a large price and you are not allowed to work on your boat.As I said the hull was smooth when pulled out,so I had the it sanded and painted.There were about forty pimple blisters.Thanks for your reply.When I pull in a year I may have do what you did.
Al Landry
Lucky #13
c34

[Miles Henderson]

Three years ago I sanded the bottom and found two large sections (a four foot section top to bottom) with pimple sized blisters (some we quite small).  I drilled each one out (went into the hull a 16th of an inch) cleaned out all the pits and put a new coat of thickened resin over the entire section, then sanded smooth and the put a thick coat (7 applications) of Interprotect 2000E on the bottom.  It has held up with no sign of problems when pulled this fall for winter storage.

[Ron Hill]

Most of the MK I's could or do have a blister problem.  I believe that Catalina didn't start using Vinylux gelcoat until the MK II's.

The biggest contributer to blisters is a poor (thin or spotty) barrier coat.  At least with the MK I's the dealers were not only responsable for applying the epoxy barrier coat, but they also liked to charge extra $$ to do the job and some new owners skipped the barrier coat.  My observation is that the dealer didn't do a good job of cleaning off the mold release and put on way too thin a epoxy coating.

I always thought that the factory should have applied the barrier coat (to protect "their" product), making sure it was done correctly and just add a boat dollar or two the hull's price.  Not too sure what the factory is doing now. 

[karista]

I will be hauling out next week to apply new antifouling paint. My diver noticed several small blisters above the waterline on the bootstripe.
He informed me, that they look like the typical blisters. I have no blisters below the waterline, I originally applied 5-6 coats of VC-TAR and it has held up well. Has anyone ever heard of blisters on the bootstripe?
What is the best repair procedure? I have read that gel-coat should not be applied to epoxy, so filling them with epoxy, as is done below the waterline would not work as I need to apply Gel-cote to match the bootstripe color.

[Jim Hardesty]

I had some blisters above the water line on my last boat, most I've see like this are at the stern where the hull slowly tapers out of the water.  During the winter layup they would all but disappear.  I was told that they were "splash blisters".  The cure was to rise the waterline with both the barrier coat and bottom paint.  I just checked it out every year and it wasn't getting bad in a hurry.  I just took the wait and see approach,and bought a new boat.  I don't think that they are much of an issue.  But then my season is only 6 months.  If I only pulled the boat every couple of years I might think different.
Jim

[Ed Shankle]

Discovered about a dozen blisters (little zits) this spring on the stern boot stripe! How does that happen after 22 yrs? That's rhetorical, my real question is, what's the recommended filler and sealer, in light of Karista's comments? I've never done blisters before.

thanks,
Ed

[Ralph Masters]

Almost a year ago at survey the bottom was good on Ciao Bella, surveyour said bottom paint in good shape and should hold for 1 - 1 1/2 years.  The diver reports all is holding up good.  So far no problems.  Looking at haul out and bottom paint next feb.  The yard says that the cheapest month because lack of work.

Ralph
Ciao Bella

[Jim Hardesty]

Ed,
You asked about blisters after 22 years.  Have you moved to a new dock?  With my previous boat I moved from a very sheltered dock, also very tight to get into, to a more open dock, thats when a few splash blisters showed up.  The boat was 26 years old.  Interesting that the the blisters were on the bare gelcoat above the bottom paint (with a barrier coat) but none were at the painted bootstripe just about 1 1/2 inches higher. 
I thought of fixing them either by moving up the barrier coat and bottom paint, or just painting below the bootstripe.  Traded up to a Catalina 34 instead.
Jim

[Ed Shankle]

My question was in reference to using gelcoat over the epoxy. I don't intend on bringing the bottom paint line up to the wide boot strip. Would look pretty ugly.

[Ron Hill]

Ed : Forget about gelcoat over the epoxy barrier coat.
 
Most yards will recommend product call "BarRust" to use as an epoxy filler on each blistered area and the same name for the barrier coat.