Barrier Coat or Not?

[TritonSkipper]

When I sanded the bottom of my Triton, I went all the way to the gelcoat. The last owner had used some old anti-foul that had been on there for 11 years.  I am in the process of filling any crazing and pits with West System resin and low density filler. I inquired on another forum about using a barrier coat like Interprotect 2000e as well, but was advised to skip that and just bottom coat when ready.  Knowing that I will be doing most of my sailing in the tropics, I was going to put out some dough and get Interlux Micron Extra. But that decision was based on the fact that there would be a barrier coat on as well. Should I still go with the Micron or should I consider something else to give the gelcoat a little more buffer. Should I worry about blistering in the future because of skipping the barrier coat? I don't have a hint of blistering now, the boat has been out of the water for 11 years, so I'm sure it's dry by now as well.

Thanks

Jeff

[TritonSkipper]

Did I post in the wrong area? I did a search before asking the question, didn't find anything.

[Tim]

Jeff, You did fine. I just think this time of year responses will be a little slower.  ;)

I have no experience with Interprotect 2000e but I am using a barrier coat additive to my West resin for the final coats on my repairs. You might consider doing that although expense and time may not make it any easier than the Interprotect.

[s/v necessity]

     TritonSkipper,
   You have probably been slim on replies because it's not a simple easy answer.  Even more, many people disagree on the issue.   Knowing the condition of your bottom is critical to the answer. *AND*, even knowing that,  there is no simple consensus as to the appropriateness or effectiveness of barrier coats and blister repair.  

   I'll stick my neck out and give you my opinion.  

   *IF* your hull is bone dry, and you have removed all the bottom paint, and filled/fixed any blisters or problems...  You wont ever find a more appropriate time to barrier coat.  It is critical that the bottom be dry before barrier coating, and this isn't something that can usually be achieved by letting the boat sit on the hard for a few weeks.

    While I cant discern if your situation warrants barrier coating or not, I would do it simply because you are probably not going to have a bottom this dry ever again. If you do it, do it right and don't skimp!

http://www.goodoldboat.com/reader_services/articles/blisterbottom.php

I'm told this boat's bottom still looks great 10 years later, without any problems.

  FWIW, there are those out there who claim a perfect bottom for years and years, and then after applying a barrier coat nothing but issues with the pox...  

     

 

[psyche]

I had some issues with my boat bottem and pealed it put 2 layers of cloth and 5 coats of battier coat prior to painting the bottom. It has been 5 years and I have had no issues with the bottom. Dan

[s/v Faith]

  (there were 2 replies while I was typing, but I am going to post anyway.....  not to step on any toes)

I am not a believer in the barrier coat marketing.

 If I had a hull that was prone to blistering, (which neither your Triton, nor my Ariel are), I might feel differently.  Thankfully, this is not a problem either of us have to deal with so it is not (IMHO) worth spending the time or money to barrier coat the hull.

 Some (many?)who do the barrier coating thing plan to never have to sand their hull again.... I think that is a fantasy.

 Whatever you put on the bottom of your boat is going to have to be replaced... although some folks try to just build up layers over the years it is not a good long term solution.  When you sand your last bottom job, you are going to sand off the 'barrier coat' with the old bottom paint wherever the barrier coat is on a high spot.... so what is the point?

 If you had a hull with known blistering problems, and you 'popped' the blisters and fared the hull where you repaired them maybe you would sleep better at night if you used a 'barrier coat' in hopes of 'protecting' the hull so you would never have to go through that again.....

 I like the fairing you are doing with epoxy, I did the same thing.  As long as you do a good wash / scrub after you are done I think you will be just fine without the added step / effort / expense of the barrier coat.

 

 

 

[s/v Faith]

Good post.  (bold added to 2 comments I especially agree with).

    TritonSkipper,
   You have probably been slim on replies because it's not a simple easy answer.  Even more, many people disagree on the issue.   Knowing the condition of your bottom is critical to the answer. *AND*, even knowing that,  there is no simple consensus as to the appropriateness or effectiveness of barrier coats and blister repair.  

   I'll stick my neck out and give you my opinion.  

   *IF* your hull is bone dry, and you have removed all the bottom paint, and filled/fixed any blisters or problems...  You wont ever find a more appropriate time to barrier coat.  It is critical that the bottom be dry before barrier coating, and this isn't something that can usually be achieved by letting the boat sit on the hard for a few weeks.

    While I cant discern if your situation warrants barrier coating or not, I would do it simply because you are probably not going to have a bottom this dry ever again. If you do it, do it right and don't skimp!

http://www.goodoldboat.com/reader_services/articles/blisterbottom.php

I'm told this boat's bottom still looks great 10 years later, without any problems.

  FWIW, there are those out there who claim a perfect bottom for years and years, and then after applying a barrier coat nothing but issues with the pox...  

     

 

[TritonSkipper]

I tell you what, that's my main problem, there excellent answers on both sides of the fence and I'm trying hard not to overcomplicate things, but this is one of the most important decisions I'll make before I put her in the water.

Thanks


Jeff

[ThistleCap]

Dear Jeff,
I've done three boats totally, and several others with varying degrees of pox.  I've had some 'pox' that on removal actually led me to hull delamination that I had to cut out and relaminate.  I started adding barrier coat over what I thought was a repaired bare hull from which I had just routed out and refilled thousands of blisters and delaminations. I applied barrier coat over the clean gel coat only to have blisters return---fewer, granted, but still nearly as many as my dog had hairs on his back. (That was on a 36-footer.)  I finally concluded, and found, that if you have bad resin and gel coat in the hull, just fixing the blisters is like painting over termite damage on the house.  The only real solution is removing the bad gel coat that allowed the damage to begin with.  Start by removing the bottom paint. Using a burr, dig into the blisters and follow them as far as they lead you.  The bad laminate will look spongy or sometimes like straw and may take you deep or several inches along the laminate.  The blister is often just an outward symptom of an underlying problem.  Do the repair to the voids produced, whether epoxy putty for small ones or having to relaminate and then fair with epoxy putty.  I start there because I find some blisters easier to find because of the damage they've done to the gel coat.  I then remove all the gel coat and repair any further blisters, voids, or delaminations  that become apparent.  When I'm satisfied the hull is pox free, I put on a new high-solids epoxy gel coat, a minimum of 5 coats with epoxy barrier coat additive.  This last time I used West.  I then put the barrier coat over the new gel coat.  A boat yard will start by grinding all the gelcoat and the first couple laminates off the hull.  The hours involved for a yard make it cost prohibitive for me, so I've done all the work myself.  It's dirty, back-breaking, and time consuming, but you can do a good job.  That's been my experience; others may vary.

[TritonSkipper]

Thistlecap, thank you for that response. I don't know if I was clear though, I have no blisters.  I only have crazing and pitting in the gelcoat on the bottom. I have been filling them with resin and low density filler. My issue is whether or not I'm going to barrier coat and if not can I or should I still use Micron Extra for the tropical cruising I'll be doing.

jeff

[ThistleCap]

Oh, well heck man, you're golden.  When I think bottoms or barrier coat, I think blisters.  They came about in the 70's after the oil embargo encouraged cutting corners and producing resins with high permeability.  If you don't have blisters, burr out along the craze line, refill with epoxy putty, sand, paint, and go.  Barrier coat is still an attempt to stop water from penetrating poor resin.  If you have a good hull, have fun, go sailing.

[TritonSkipper]

  (there were 2 replies while I was typing, but I am going to post anyway.....  not to step on any toes)

I am not a believer in the barrier coat marketing.

  If I had a hull that was prone to blistering, (which neither your Triton, nor my Ariel are), I might feel differently.  Thankfully, this is not a problem either of us have to deal with so it is not (IMHO) worth spending the time or money to barrier coat the hull.

  Some (many?)who do the barrier coating thing plan to never have to sand their hull again.... I think that is a fantasy.

  Whatever you put on the bottom of your boat is going to have to be replaced... although some folks try to just build up layers over the years it is not a good long term solution.  When you sand your last bottom job, you are going to sand off the 'barrier coat' with the old bottom paint wherever the barrier coat is on a high spot.... so what is the point?

  If you had a hull with known blistering problems, and you 'popped' the blisters and fared the hull where you repaired them maybe you would sleep better at night if you used a 'barrier coat' in hopes of 'protecting' the hull so you would never have to go through that again.....

  I like the fairing you are doing with epoxy, I did the same thing.  As long as you do a good wash / scrub after you are done I think you will be just fine without the added step / effort / expense of the barrier coat.

 

 

 

Craig,

I'd much rather not spend the $80/gallon., so this gives me a low grade warm and fuzzy.  I don't want to open a can of worms with this question, but after my filling is done and sanded, is Micron Extra still the way to go for tropical cruising.  I know that it is based on personal choice, my choice is the Micron unless I'm absurdly wrong.

Jeff

[ThistleCap]

Jeff, it's hard to say a particular paint is 'wrong'.  Micron is a good paint.  It's advantages are the additiion of biolux, the fact that it can be stored on shore without losing effectiveness if you need to do other work on the boat, and it's an ablative.  When we worked in the V.I., several of our boats had ablatives on them, and it worked well.  I don't remember the particular brand.  Regardless of what you use, the waters down there are perfect for growth, so you'll have a ecosystem on the bottom that will need cleaning monthly.  The more you sail, the less you need to clean, and cleaning too vigorously will remove paint.  Since the waterline will be cleaned most often, put a couple extra coats from the boottop to nearly a foot below the actual waterline.  If you want definitive input, get the results from Practical Sailor's latest bottom paint tests.  
http://www.practical-sailor.com/issues/paintcoatings/xref.html

[TritonSkipper]

Thanks ThistleCap, Grog for everyone. Cheaper than buying a round, not to say I wouldn't buy a round cuz I would. I have a long and distinguished history of financing pints of pleasure for a crowd lol

Jeff

[CharlieJ]

Tehani had zero blistering when we got her. She'd been out of the water for 15 years. Sanded the hull, applied three coats of WEST 422 barrier additive in epoxy. Then two coats ACP 60.

Three years later at next haulout, we had many small blisters. Dug them out, epoxy filled, faired and then applied 4 coats (2 gallons) Interprotect 2000E.  Overcoated with two coats ACP 60.

I'll tell you next haulout how THAT worked. But it should be a couple of years.

Remember though- never has a boat sunk just because of blistering.