Barrier coating

[Saltydoc58]

So…. long story short…. After having boat yard scrape all the bottom paint off in March… foreman and workers quit before finishing the job.
So this 63yo surgeon with bad shoulders has been on his back sanding and plans to barrier and bottom paint myself next weekend to salvage June.
Hull( 1998) in excellent shape -not a single blister or bleb…. Superb Maine craftsmanship. Gel coat is blue tinted. Sanding and prep almost complete.

Which barrier coat product to use - Petit, Total Boat,Seahawk, etc

 

[Genius]

I usually stick with the same brand of paint I am using for the bottom paint. The silver epoxy from Interlux. HS?

 

[goin4broke]

Second on Interlux HS. Less coats and time intervals. Be sure your down to gelcoat and wash a couple times with soap/water then the Interlux 202 wash.

 

[Saltydoc58]

Probably will lean toward compressed air blowing and solvent wipe downs to avoid wetting hull now that it has dried out for 5 months.

Interlux recommends MONTHS of dry time after their wash or “ forced drying”

“

 

[Genius]

Probably will lean toward compressed air blowing and solvent wipe downs to avoid wetting hull now that it has dried out for 5 months.

Interlux recommends MONTHS of dry time after their wash or “ forced drying”

“

I don’t believe that.

You just need to sand, vacuum, mechanically wipe with solvent and or broom.

 

[goin4broke]

Probably will lean toward compressed air blowing and solvent wipe downs to avoid wetting hull now that it has dried out for 5 months.

Interlux recommends MONTHS of dry time after their wash or “ forced drying”

“

Spraying the surface is much different than the osmosis issue from months of immersion. Especially if the gelcoat is in tact and no blister issues as you have indicated. However, as long as your solvent rag is coming off the hull clean you should be good to go.

The wash just helps get more residue off prior to using expensive chemicals. I’m not keen on a compressed air “blow job” and your marina may have a say in that.
A vacuum with a brush head would be better.

 

[Saltydoc58]

Understood- thanks for input. Plan to finish up prep this week after work, buy paints and supplies- and hit it this weekend.

 

[ThePartsGuy]

We use the Seahawk's Tuff Stuff for barrier coat in our yard exclusively. Perfect hot coat times and high build for mil thickness in as few as 2 coats. Whichever brand you choose following the Standard Operating Procedures the manufacture has laid out will be the key. They 100% do NOT want you to fail for their brand protection if nothing else.

Good luck!

 

[BillD]

We use the Seahawk's Tuff Stuff for barrier coat in our yard exclusively. Perfect hot coat times and high build for mil thickness in as few as 2 coats. Whichever brand you choose following the Standard Operating Procedures the manufacture has laid out will be the key. They 100% do NOT want you to fail for their brand protection if nothing else.

Good luck!

Agreeing with Bill The Parts Guy.........
I've used SeaHawk barrier coat (it's a gray color) on two hulls now. Two part easy mix, high build, two coats same day...followed up by three coats of Seahawk AF33. Excellent working times.

 

[osprey47]

Good experience with the Pettit barrier coat. Did a 47' sailboat: three coats alternating grey and white. That said, I do like the results of Interlux products.

Sanding your bottom paint. This is a young person's task. I have had two boats powder blasted with excellent results. One the 47 footer, the second, my BHM-36 and the barrier coat put down many years ago was in excellent condition.

 

[Ronin120]

Well, I can suggest what NOT to do. A cautionary tale.

For reasons that I have conveniently forgotten I ended up with a full 3 gallon kit of Interlux Interprotec 2000E and 4 gallons of Sea Hawk Monterey water-based antifouling sitting in my shed.

The bottom, original from 1998 and falling off in chunks, had been "sand-blasted" in February and left to dry out. They did not do a good job. Like the OP, I had to spend time sanding those areas before applying materials. And I'm 70. Damn near killed me...

Anyway, after RTFM, I realized that putting a water-based antifouling over the Interprotec was not optimum. I consulted with the yard owner. We figured that putting a black "guide" coat of Interlux Fiberglass Bottomkote NT per Interlux's direction, I should be somewhat safe with the following three coats of Red Sea Hawk Monterey.

Time will tell. I dive on my boat (former sailboat racer...) so I'll be able to see how it fairs this season. I'll report back.

 

[Fishnjess]

I used interprotect 2000e in ‘18 with 3 coats alternating gray white gray. Followed by 2 coats of Interlux Fiberglass Bottomkote NT, blue then black. She held up nice when coming out in the summer of 20.
But, I looked at a bottom done with sea hawk barrier coating and was impressed with the results.

 

[Genius]

...as always read the instructions with whatever you choose. It's been my experience that the tie coat between barrier coat (epoxy) and the first coating of bottom paint needs to be timed correctly to get the chemical bond. It isn't just a mechanical bond that gets the good adhesion. If not done correctly, I've seen it fail. That is kinda why I like to stay within a paint companies "system". see below for Intlerlux HS notation:

"Note: If maximum overcoating time with antifouling is exceeded, sand with 80220 grade (grit) paper (coarser grade is unsuitable for above water areas), or apply an additional coat of InterProtect HS"

 

[mmac1913]

So…. long story short…. After having boat yard scrape all the bottom paint off in March… foreman and workers quit before finishing the job.
So this 63yo surgeon with bad shoulders has been on his back sanding and plans to barrier and bottom paint myself next weekend to salvage June.
Hull( 1998) in excellent shape -not a single blister or bleb…. Superb Maine craftsmanship. Gel coat is blue tinted. Sanding and prep almost complete.

Which barrier coat product to use - Petit, Total Boat,Seahawk, etc


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For what it's worth, I used Interlux 2000E, 4 Coates after blasting the old stuff off, I hired a great guy did and exultant job of blasting. Followed the barrier up with 3 Coates of Seahawk AF-33, we will see how it all plays out this fall when we haul.

 

[Eye doc]

Recently purchasing a 38 yo 31’ JC, I had the task of redoing the bottom. When I hauled out, I saw that I had an ‘osmosis’ isuue. With the guidance of Shor 2832, I set out to rectify the problem. Getting a good grinder/extractor was key. Soda blast/ grind/ sand /wipe. One coat of Interprotect 2000, filling in holes with Interprotect Watertite, 4 more coats of Interprotect, 2 coats Micron CF