Barrier Coat - Bottom Clean Enough?

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AvalonGB

Veteran Member
Joined
Nov 11, 2014
Messages
59
Location
USA
Vessel Name
Avalon
Vessel Make
Grand Banks 46 Classic
Having bottom blasted followed by barrier coat and then paint; 3 coats of each. Yard says bottom is clean enough to barrier coat but to me looks like they have not removed all the paint. My understanding is all paint must be removed prior to applying barrier coat.

Am I correct? What is your opinion on applying barrier coat over bottom as shown in pictures?

Also having chuck out of keel inspected and repaired. Looks like an old injury but probably should address anyway.

Thanks for the feedback
Tim
 

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No way...clean, white gel.

I wouldn't trust the yard to do ANYTHING else.....barely to put me back in.


AND dry laminates under..otherwise you are sealing in the problem.
 
Last edited:
I agreee with Psneeld. I had mine soda blaster down to the gel before the barrier coat--there was no paint remaining.
 
My expectation was all paint would be removed. Looks like they have some more work to do.
 
Greetings,
Mr. A. Fully agree with the above. That bottom is nowhere close to being ready for barrier coat and as Mr. ps stated, make doubly sure the repair is done on a DRY substrate. In future, I'd look for a more reputable yard...
 
Greetings,
Mr. A. Fully agree with the above. That bottom is nowhere close to being ready for barrier coat and as Mr. ps stated, make doubly sure the repair is done on a DRY substrate. In future, I'd look for a more reputable yard...

RT - by substrate are you referring to the floor? She's inside a building on a concrete floor.
 
Greetings,
Mr. A. Sorry for the misunderstanding. By substrate I mean the keel/damaged area or as Mr. ps noted "...dry laminates under...". I suspect the damaged area will have to be ground back to solid material, allowed to dry thoroughly then repaired.
 
RT - by substrate are you referring to the floor? She's inside a building on a concrete floor.



No, the substrate is the fiberglass hull itself down to the gelcoat .
Nothing to do with the building.

RT also emphasized DRY. FRP absorbs water which is why you want that barrier coat. Unless the hull [substrate] is given enough time to dry out then that moisture, trapped by the barrier coat, will cause barrier coat failure later.
 
We summer in Noank. Not there now.
 
No way is this ready in my opinion. What brand of paint are you using? Call the manufacture and ask them.

Several years ago, I sanded the bottom on my Sea Ray down to the gel-coat. Then I fixed places that need attention.

I used InterLux. I applied 5 coats of barrier coats, alternating colors grey and white. The last coat was white. (you can see when you needed a new paint job).

This is important. On the last coat of barrier, apply it and then do the "Thumb Test." Place your thumb on the paint and then pull back. If you leave a thumb print on the paint then you need to apply the 1st coat of bottom paint immediately. Don't let it dry completely. You may need friends to help. This creates a chemical bond. Then add the recommended number of coats recommended by the manufacture.

The above procedure is what InterLux gave me for their paint.
 
It is clean enough only if you want the barrier coat to come off with the bottom paint that is still on the hull. Bare gel coat only for the barrier coat.
 

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