Barrier Coat?

[Clay Greene]

So, Serendipity is having the old bottom paint taken off today and we were debating whether to take it down to the fiberglass or to try to save the barrier coat.  The flaw in that thinking is that we were assuming we had a barrier coat.  From the test patch they did this morning, it does not look like one was applied.  Can anyone with a similar-aged boat (1989) report on what they have found when removing the old bottom paint?

[patrice]

Hi
I am interested in the answers you'll get.
I'm in the same position as you.  The antifooling is getting away in patch.  With all the layers it got over the years.
By the waterline area, I can see the gelcoat.  Being in the water far a couple of months a year, was wondering if can be armful to the hull.

[Ed Shankle]

Mine is an 89 and no, there wasn't a barrier coat on it. A couple of years  after buying it, I took it down to the gelcoat and applied the barrier.

Ed

[Jim Hardesty]

Don't think that the factory did barrier coats.  Just like bottom paint.  It's something that that the dealer does or not depending on what the customer wants.  Or will pay for.  So, some boats one year may be barrier coated, some may not.
As far as not having a barrier coat being harmful.  Are you getting blisters?  If not the work/expense of doing one may not be worth it.  A lot of the work, money, time is prep, getting down to the gellcoat or fiberglass, and drying the hull out.  After that applying the barrier coat is time sensitive.  If you can't follow the schedule.  You need to sand before the next coat.  Barrier coating is a simple job, but a big one.  If not done when the boat is new.
Jim

[Clay Greene]

FYI, I spoke to the dealer and he said that they were not doing barrier coats at the time unless the customer requested it.  Catalina was marketing a new fiberglass that was blister-resistant that came with a five-year warranty.  (Which, by the way, seems to have worked - 23 years later and no blisters!   )  He suggested a good cleaning with the one of the Interlux or Pettit products followed by sanding with 60-grit, a coat of epoxy primer and then the antifouling paint. 

For what it is worth, the Pettit Protect epoxy primer/barrier coat is not as time-sensitive as the Interlux Interprotect and it is supposed to require fewer coats. 

[TonyP]

Clay
I have some pics on a post called 'bottom peel' of blisters we found. I can't do a cut and past on my iPad.
I wasn't able to get a pic of the barrier coat before they did the anti foul.
Good luck with it
Tony

[Ron Hill]

Clay : The "new vinyl gelcoat" that was used by Catalina was not in production until the 1990s!!  The boats were sent from the factory bare bottom and the dealer was responsible for the epoxy barrier coat (a BAD Catalina decision - in my opinion)!

There been a ton of stuff written on this topic of barrier coats.  In synopsis:
Take all the paint off, scuff up the bottom with 60 grit, apply 3 coats of barrier epoxy in at least 2  different contrasting colors, before the final epoxy cures apply a hard bottom paint (contrasting color so it also chemically bonds) and then 1 or 2 coats of ablative (again in a contrasting color). 
With the contrasting colors of paint you know what is happing when that hard color appears and the ablative is wearing thru as it should. 

A few short thoughts

[horsemel]

We had Blue Moom barrier coated three yeats ago.  We were getting hundreds of small blisters about 1/4" or smaller that seemed to grow into somewhat larger ones the following year.  When I looked at the time and effort involved I concluded that it would be better to have the barrier coat put on for us.  No regrets and no blisters.

[Clay Greene]

Upon further examination, we did have quite a few very tiny blisters, mostly about the size of a pencil eraser, and located just below the water line to about three feet down and almost all between the pads of our cradle.  You can only see them when the sun is out which is why I missed them originally.  The surface of the gelcoat is just slightly raised - they're not anything that could be seen with the bottom paint on.  If we open them up, they are dry inside.  There were a couple that were bigger so we opened those up but again no water or moisture inside.  So, we are going to fill the ones we opened with epoxy, give the boat a good washing and sanding and then put on three coats of an epoxy barrier coat before two coats of antifouling paint. 

Ron mentioned using an ablative paint, which is what we had used before (Micron CSC).  For whatever reasons, ablative paints do not seem to work well in our part of Lake Michigan.  We don't get barnacles or weeds but instead get a green, algae-like slime.  Probably 50 percent of the boats in our yard have a hard racing paint, either VC-17 or the Pettit equivalent, SR-21.  It is the only thing that seems to keep the slime off. 

[Ron Hill]

Clay : The only reasons that I use ablative is because:
1. The old Chinese proverb says, "the more hard bottom paint that you put ON - the more paint you'll have to take OFF!!  Hard paint is much harder to get off than softer paint. !!
2. I've had seasons that I have only repainted the water line and not the entire bottom.  You can do that with ablative!!

A few thoughts

[Footloose]

Clay

In fresh water, go for the VC 17.  With the short season we have, you will be able to go 1-2 years between touch ups.  You have a long way to go to get to salt water from Milwaukee.

[Clay Greene]

I love the idea of ablative paint, which is why I put three coats on five years ago.  We were still working on the first coat on most of the boat - the second coat (in contrasting color) was showing through in just a couple of places.  But that illustrates the problem - it does not seem to ablate in fresh water, which is what it needs to do in order to keep growth down.  And we use our boat a lot - three to five times per week during our season.  Believe me, the last thing I wanted to do was take it all off and start new with SR-21, the Pettit equivalent to VC-17.  But I was slower than my friend's Mark II boat and my sails are newer, and there are some things one just cannot abide. 

[Ken Heyman]

On "Wholesailor" (1988 #535), after talking to Catalina, I did put on a new barrier coat. Catalina claimed that the boat had a "barrier coat" but after 23 years was no longer "effective". I certainly believed that. I also had a previous owner situation where VC 17 was applied over an ablative bottom paint which is a no-no and I wanted to correct this. I had the bottom sanded and 5 coats of new barrier applied. ----Probably a good idea in boats of this vintage-even without any obvious problems.
Ken