Barrier coat life span?

[Wild Life Management]

I have a barrier coat on my hull that was done by the previous owner, so I can only guess as to when it was applied.

I have made some phone calls and received very different opinions, from "as long as it's still adhered well it should last forever" to "if it's 8 to 10 years old it's time to blast the bottom and apply a new barrier coat."

So . . . . . what do you think?

[clt_capt]

Assuming the barrier coat is something like Interprotect (epoxy) it should outlast your boat - If the hull was prepped and cleaned right and a couple of coats applied (as recommended)

Are you seeing flaking of the paint? Is the barrier coat popping off? Also how much buildup of old bottom paint do you have?

Are you at risk of breaking through the barrier coat while sanding the old bottom paint?

[frankypettolina]

between 8 and 12 years has been what I have seen.

[Wild Life Management]

Are you seeing flaking of the paint? Is the barrier coat popping off? Also how much buildup of old bottom paint do you have?

Are you at risk of breaking through the barrier coat while sanding the old bottom paint?

I think it was interprotect, and there is no flaking at all. Every spring, and sometimes in the middle of the season, we haul the boat and clean the bottom with a power washer. There are only two, maybe three, layers of bottom paint on the hull at any given time, so there isn't much build up at all. I've seen the power washer directly hit the few spots where the barrier coat was exposed and it is still adhered very well.

[frankypettolina]

I failed to elaborate on this, so i will be clear here. The recurrence of blisters that I have seen usually shows up in the 8 to 12 year timeframe. have i seen it last longer, yes- have i seen it last less time- yes. It all depends. Another well respected member of this forum sent me a pm about this, and I will give you the same answer i gave him. I have seen at least 20 to 30 boats have a recurrence of blisters in the time frame I mentioned. I know many other surveyors who have seen the same thing. There are alot of variables here. how long is the boat in the water- year round? hauled seasonally? These things come into play. As far as how we can be sure as to how long the coatings last... Remember these coatings have only been used in abundance since the late 1980's. We are just starting to learn what happens when they get to be 20 years old.

In your specific case- if it ain't broke don't fix it. If you don't see any problems go on business as usual.

[jawz12]

osmotic blisters and barrier coating...


epoxy barrier coating should last indefinatley,if applied properly,solvent washed surface,free of any and all antifoulant residue,dewaxed,etc,these steps have to be taken.personally,i've never seen a failure of barrier coat.i've seen some bad bottom jobs.the barrier coat is an epoxy,it's water proof,it's only as good as the surface it's atached to.i've seen and know guys in the buisness who put one coat of barrier coating on and call it a day-the coating needs to be 10mils thick to be effective-i go by the "matchbook cover" test.trust me,this stuff is water proof,hence the name "barrier coat".if this was the case,barrier coat lasting 8-12yrs,i would have alot of boats back at my shop with the barrier coat popping off-that's just not the case...
in the case of osmotic blisters,and them reoccuring,that's a different story.if the blisters have "reappeared",was the hull properly dried out prior to the application of barrier coat ?? personally,again,i've never seen "reoccuring" blisters.osmotic blisters are water trapped between the gel coat and the substrate,if the gel coat was blasted off,and any delamination areas properly repaired,along with theull being allowed sufficient time to properly dry out-and that "dry out" is verified by a moisture reading,the odds of osmotic blister reoccuring is about slim to none...i have a maxum at the shop right now,osmotic blister problem,the entire hull's bottom is covered,late model boat too...the bottom will be blasted to remove the gel coat,that boat will be sitting on the hard 'till the mositure meter reads an acceptable number,then the barrier coat will be applied...

using all these products and doing a bottom job,certainly isn't brain surgery,trust me,it's not analytical geometry,and it's not launching a space shuttle either,it's a pretty straight forward job.following the directions is another story,using common sense and trying to get a job done is a whole 'nother story too...

more on bottoms...

antifouling paints...

if you went throught he trouble of having the bottom of the boat blasted,then barrier coated-to remove a paint build up,then,why would you use the same single season paint again ???
i see guys doing this all the time...

[frankypettolina]

Jawz- could not agree with you more about the bottom paints.

And to add something else to what I wrote above- the big question is always "if" it was applied right. And the other key word is "should" last forever. If and should are really important here. And the reality of it is that know one knows 100% on either of these.

I may not be using my words properly, but the bottom line is that I have seen blisters on boats that were barrier coated. The average time frame that i have seen the blisters on boats that were barrier coated falls into the 8 to 12 year period after the coating was applied.

As a surveyor i do not "fix" boats. I observe and report. Thats all. Jimmy fixes boats and can speak more about what he has done and what he has seen on the work he has done. While I don't know him personally, he has an excellent rep in the business, and if he says that he has never seen a problem with the work he has done, I believe him.

And again, to Wildlife managament- IF it appears that your bottom is fine, I wouldn't mess with it. you SHOULD not have any problems.

[Wild Life Management]

IF it appears that your bottom is fine, I wouldn't mess with it. you SHOULD not have any problems.

I'm just gonna go with that for right now. I'll make a note to think about it next spring.

Franky and Jimmy, thanks for the info guys. I'm going to try and contact the old owner to see if he can tell me the who/what/where/when about the barrier coat. If I knew it was done 6 years ago by a reputable place I'd feel a lot better. If he tells me his brother Bo Dan put it on in '95 utilizing a foam brush and a six pack, I'm blasting it.