The necessity of a barrier coat???

[SiXeVeN]

How critical is a barrier coat? Probably more to the point, what does a barrier coat do?

If my boat has a non-cored hull... i.e. solid glass. do I need a barrier coat or can I just prime and paint. It will practically double my expense to have a barrier coat placed so I would rather not...But I want to do what is appropriate.

BTW she will be kept on saltwater 24-7

[DrB]

If you leave the boat in the water 24/7 for many months, AND it is a Glass/Polyester resin boat, at some point, the likelihood of you getting blisters on the boat is high.

If you plan on parking your boat in the salt water for many months, a barrier coat is probably a good idea.

DrB

[jarcher]

SiXeVeN, I feel your pain! I am going through the same decision now. In my case, it more than doubles the cost

[johnshasteen]

Paloma is 30 years old and has been in salt water since 1979, coming out about every three years for a bottom job (annual quick hauls for power washing and check/replace zincs). Solid glas hull, never had a barrier coat and never needed one.

[SiXeVeN]

That is what I have been suspecting. I thought blisters only happened on cored hulls where the fiberglas delaminates off the coring. I guess you could also get small delamination between fiberglass layers too but that would be difficult with a solid resin hull.

[sailingdog]

Blisters and delamination are two different things... any fiberglass hull—cored or solid—can blister, where water has gotten into the laminate via osmotic pressure and created blisters under high pressure that are filled with a fairly acidic substance. However, cored hulls can also delaminate, where water has gotten into the core area and either separated the foam from the laminate skins or rotted the balsa core material.

Originally Posted by SiXeVeN

That is what I have been suspecting. I thought blisters only happened on cored hulls where the fiberglas delaminates off the coring. I guess you could also get small delamination between fiberglass layers too but that would be difficult with a solid resin hull.

[sailingfool]

If a boat shows no blistering from prior use, and is going to continue that form of use, then in my opinion, a barrier coat is not necessary. The purpose of the barrier coat is to prevent blistering...if an experienced boat has no history of blistering, why bother?

Note that being in warm water for 12 months a year is heavy use. If you were taking a Northern boat to Florida for the first season, the risk of blisters would increase dramatically from its prior use, I'd do the barrier coat then just to be safe. But if the boat has been in such waters in prior years, what's to change?

[T37Chef]

Consider what it cost to do a barrier coat, then consider what it will cost if a blister repair job is in order, I think you'll find it an easy decision

[jarcher]

Originally Posted by T37Chef

Consider what it cost to do a barrier coat, then consider what it will cost if a blister repair job is in order, I think you'll find it an easy decision

What is the cost of a blister repair job? If blistering starts, is it just one or two, or do a bunch break out at once?

[sailingfool]

Originally Posted by jarcher

What is the cost of a blister repair job? If blistering starts, is it just one or two, or do a bunch break out at once?

The cost of a blister repair job will vary as widely as the blistering conditions that might occur on a boat - from a few inconsequential dimples safe to ignore to a fully cratered, water saturated bottom needing a peel and recore repair. Read through Hull Blisters on Boats and Yachts - by David Pascoe, Marine Surveyor if you want to understand some of the causes and impacts of blisters.

Again, if the boat has been used where and how you plan to use it, inspection of the boat will tell you it's suspectability to blistering.