Barrier Paint?

[SeacretSailor]

I have a quick question for the southern warm-waters sailors. My area will be the warm brackish waters of Lake Pontchartrain. I'm buying a "new-to-me" boat in 4 weeks and prior to buying it, I'm having it hauled and getting a fresh bottom-job with Pettit Trinidad. It stays in the water year-round and get's hauled every 2-3 years. The PO told me that he gets 2-3 years worth of protection with Trinidad and that it does not have a barrier coat applied.

My question, based on your boats, would y'all suggest me definitely having the yard apply a barrier coat before the bottom job or continue just getting a fresh bottom job every 3 years? Are barrier paint jobs necessary in southern waters?

I'm a former Trailer-Sailor, so this is one of many new areas for me as I graduate from a Macgregor 26S to a C&C 29 footer.

Kevin

 

[pvanv]

Barrier coat is more important in warmer water. Also more important if not hauled every season. Likewise more important in Salt. But you would need to strip everything down to the gelcoat to apply it.

I'm mid-way in barrier-coating our boat as I write this.

Any good epoxy is a decent barrier coat, but some are better than others. West makes an additive for their 105 resin specifically for barrier coating, and Interlux has both 2000E and 3000 coatings. Big thing is that you want sufficient coating thickness to be effective.

If there aren't any blisters, now would be a good time to get the barrier coat on to prevent them. It's also a great time to fair the hull, especially if you will be racing.

If there are blisters, then you need to repair that problem before barrier coating. Minor blistering can be opened, washed, thoroughly dried, and filled. Extensive blistering usually requires a gelcoat peel to be effective.

 

[Rick D]

Barrier Coat Warning

The hull must be dry or you will trap moisture in. At least that is what I was told by a yard who advised me against it unless I let the boat dry out for a considerable period at a very considerable storage cost. That was my gut feel too which the yard confirmed, but I have not trued that up with either the boat or coatings manufacturer. Point being, do some due diligence on that before you proceed.

 

[sailaway78]

From what I read

From what I have read in my research on this subject, you do not need a barrier coat if there are no blisters, or very very few blisters. There is something about the origional layup of the hull, that either will blister or won't blister. If you are going to put a barrier coat on it, you must let the hull dry completely or you are just wasting your money. This can take a long time, depending on humidity, temp, moisture in the glass, etc. etc. In this area, the Interlux 2000 seems to be the barrier coat of choice. Trinidad is a very good bottom paint for the area, and I always get at least three years out of it. For the very best yard prices around, take it over to Lake Catherine Marine, it's in behind Ft.Pike, right at the hwy. 90 bridge. If you want more info. email me, or post up.

 

[Ted]

Barrier Coat

There are always exceptions to common belief so I'll share this story with you and let you make a decision. A few years ago my brother decided to strip all the bottom paint off his early 70's Westerly. The boat had a good amount of old, chipped and flaking bottom paint on it. I suggested that he put on multiple coats of Interlux 2000 prior to applying the bottom paint. His boat never had a single blister for all the years he owned it so he thought a barrier coat was not necessary. He skipped the barrier coat and bottom painted directly over the gelcoat. Fast forward two years when he pulled the boat out of the water for a cleaning and a fresh coat of bottom paint. To his horror, the entire bottom of his boat was covered with blisters. Some bottom paints can act like a barrier coat, especially vinyl based paints. So I suspect that the old paint was doing so in this case. If you go through the trouble of stripping your bottom paint down to the gelcoat, I would strongly suggest that you barrier coat prior to bottom painting. You must remove all traces of old bottom paint prior to applying a barrier coat. You really don't want to have to do that job again or worse, have a blister problem. A few hundred extra dollars spent now can save you many thousands down the road.

Boats in warm water are more susceptible to blisters. C&C 29.......nice boat. I have the mkII version. C&C made a quality product but like all manufacturers was not immune to moisture problems.

 

[higgs]

I am a cold water sailor where blisters are not as much of a problem yet they do occur. For my money, if one is to strip the bottom all the way down, NOT applying a barrier coat is nothing short of stupid,. It is not that hard, not that costly, and great insurance.

 

[Maine Sail]

When a reputable

When a reputable yard does barrier coat job they will measure the moisture content and allow the hull to sufficiently dry before applying a barrier coat.

Drying a hull can take many, many months in a dry climate or dry building with low moisture content. Up here in Maine they'll often strip it in the fall and let it sit all winter before applying the barrier coat to ensure it's dry. Keep in mind some of these boats sit in the water for only three months per year and it still takes all winter to dry the hull sufficiently.

These are spot tracings of the physical moisture meter and the resulting moisture reading and date taken. They will be compared again in the spring before the barrier coat is applied. If not dry enough the boat will continue to sit and dry.

You should not apply a barrier coat to a wet substrate..

 

[SeacretSailor]

Thanks for the thoughts, some things were sure easier as a Trailer Sailor....

I'll ask some of the local boatyards their opinions and maybe run it by Pettit. My theory on why some boats in the area don't is maybe because the Trinidad hard epoxy acts like a barrier coat. Again though, only hauling eevery 3 years has me concerned, but that's what most boaters on lake Pontchartrain do.

 

[sailaway78]

Where on Ponchatrain

Kind of depends too on what part of Ponchatrain your on. Water can be brackish to fresh depending on location. I live on the east end, so is mostly brackish here, but farther up the lake is more fresh. Up in the Mandeville area, Marina Del Ray on the river, is basically fresh water.

 

[Ross]

Re: When a reputable

I like the shape of that hull ! Who was the designer and who was the builder?

 

[Maine Sail]

Hard to tell

I like the shape of that hull ! Who was the designer and who was the builder?

Hard to tell 100% with the cover on but she looks an awful lot like a West Snail to me....

 

[Ross]

Re: Hard to tell

Thanks!

 

[sailaway78]

Call Maritime Systems

Maritime Systems in Slidell is one of the best yards in the area. DIY allowed. But they are about the highest priced yard around too. You can give them a call, and see what they say. I know they do a lot of blister repair, and barrier coats. Have no doubts that Trinidad will be good for three years here.

 

[Prime Time]

Controversial Topic

I'd check the moisture content of the hull. I wouldn't barrier coat an older boat that has been in the water for many yrs and doesn't have a moisture problem. Even if there is high moisture, but no damage, what to do isn't clear. If your hull is a cored laminate, a wet hull could have significant consequences though.

This is such a controversial topic. All gel coat is porous, yet not all boats develop moisture degradation issues. My dads boat is an example. His 1972 bristol has for years had moderate to high moisture readings with a meter. No blisters ever.. Recommendations of what to do by many "experts" have ranged from doing nothing, to barrier coating, to peeling the gelcoat and barrier coating. We have taken a wait and see approach.