Barrier Coat

[triple duece]

Ahoy Everybody;
Having the bottom Soda blasted next week and want to put a coating on her before the bottom paint.
On my other boat (Old Town DV1780, 1970 vintage) I had a problem with Epoxy adhering properly to the Polyester resin the old girl was set up with. Anyone know what resin Aquasport used in 1987.  :study:

[Capt. Bob]

Ahoy Everybody;
Having the bottom Soda blasted next week and want to put a coating on her before the bottom paint.
On my other boat (Old Town DV1780, 1970 vintage) I had a problem with Epoxy adhering properly to the Polyester resin the old girl was set up with. Anyone know what resin Aquasport used in 1987.  :study:

For your selective reading.

viewtopic.php?p=28230#p28230

Good luck.

[gran398]

Trip,

Captain Bob has posted a good reference. After review the old thread is inconclusive.

The boys made good points re adhesion....sort of like painting an old kitchen, enamel/latex/ enamel etc.

Scheduled to soda-blast our rebuild hull next week. Will remove bottom paint, then hull gelcoat, blasting down to good gel or even no gel in places. They say no more than 2 hours, $200.00 max, they come to you.

Rebuilder's plan is to hang her straight-up from the bow eye from a big fork lift...soda blast the whole mess. Then spray gelcoat two coats minimum entire hull. The soda they say is a huge labor savings in terms of sanding/filling/sanding.

Bottom line the rebuilder says to keep it all the same...that is, poly on poly. (Gel over gel).

Hope this helps. Good luck sir.

[John Jones]

I have used this on two different hulls with great results.
http://www.jamestowndistributors.com/1/ ... rimer.html



ONLY CERTAIN PAINTS ARE COMPATIBLE.

Both hulls were repaired with both West Systems Epoxy as well as Boatyard polyester Resin.  It just depended on what I had on hand or how slow or fast of a cure I was looking for at the moment.  I had zero issues with adhesion and the repairs were no problem to paint over.  Last week I talked to the guy who bought my '79 CCP.  He has had no issues with the hull paint.  That is probably about 5 years now since I painted the bottom.  

It's all about three things.
1 - prep
2 - read and follow the freaking instructions and compatibility charts on the epoxy, the primer, and the paint before you buy anything.  
3 - prep

Curing epoxy gives off "amines" that do not sand off.  You need warm soapy water and a Scotchbrite pad.  However, improperly mixed epoxy (i.e. too much hardener) can give off amines for months after it appears to be cured.  Amines cause all sorts of problems with paint.  It can stay tacky or create what they call a "blush" over the repair.  Some paints just will not stick to epoxy no matter what you do.  The simplest thing to do is not use epoxy resin for repairs unless you have the determination to jump through all the hoops necessary for a good job.

There are links to some good info on the page I linked above.

[John Jones]

Oh yeah, don't forget that Marine Tex is an epoxy.  Fill a screw hole now because it's easy and 3 years later you try to paint over it without the proper prep and you will have issues.

I am no pro on this stuff, I just learned the hard way.  ;)

[triple duece]

Thanks to all, whose advice I appreciate but since it is Good Friday, I won't act like a fisherman but instead will tell the truth. I took the Lazy Old Man's way out of the dilema and hired a professional blasting co. to do the work. It was a bit pricey but to me worth every penny.  Soda Blasted, two barrier coats and two coats of ablative bottom paint. They patched the areas that were in question after the blasting then proceeded with the barrier coating, painting and clean up. It'a also guaranteed for 3 years so I think it was money well spent.
Again, thanks to everyone for their input.
Triple Duece