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Hard bottom over antifouling

Dec 19, 2006
5,733
Hunter 36 Punta Gorda
I am hauling in another week and going to usehard bottom over my antifouling paint with a special primer so says the boat yard so has any body done this.
My diver is super cleaner and spends over hour some times 2 hours so my paint is wearing sooner and switching to Blue Water hard bottom paint.
Wish me luck.
Nick
 
Oct 22, 2014
16,130
CAL 35 Cruiser moored EVERETT WA
Good luck Nick
In our cool climate / waters I had yard put Pettit Trinidad over a soft ablative painted by a previous owner. Boat in water 365 nights. Diver says paint is holding up.

Prep included pressure water wash down, sanding of old paint to create solid surface, dry out, then 2 coats of PT.
 
Jul 7, 2004
8,018
Hunter 30T Cheney, KS
What John said. You need to get down to a firm surface or the hard paint may slough off with old ablative.
 
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Feb 26, 2011
1,256
Achilles SD-130 Alameda, CA
Yes, you can use a hard paint over an ablative. It's all in the preparation. It is a fallacy to claim otherwise.

BTW- It's all anti fouling paint, whether it's hard, ablative or otherwise.
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
I have found that some solvent based paints can’t be put over some water based paints. For example, you can’t apply micron 66 (solvent) over Hydrocoat. (Water based). We sanded the old Hydrcoat off before applying the Micron 66.

If you don’t know what kind of paint is on the boat, you can apply a test patch of the new paint over the old, following the manufacturers instructions that you can find online.
 
Feb 26, 2011
1,256
Achilles SD-130 Alameda, CA
I have found that some solvent based paints can’t be put over some water based paints. For example, you can’t apply micron 66 (solvent) over Hydrocoat. (Water based). We sanded the old Hydrcoat off before applying the Micron 66.
Yes, the paints must be chemically compatible with each other.
 
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Jan 11, 2014
7,849
Sabre 362 113 Fair Haven, NY
What does the paint manufacturer say? They should know their products.

A really good hard pressure wash will get rid of much of old ablative paint.
 
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Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
What does the paint manufacturer say? They should know their products.

A really good hard pressure wash will get rid of much of old ablative paint.
Unfortunately, using a power washer to remove anti-fouling paint pollutes because the waste water drains into the local water table or system (unless there is a filter in a catch basin system to remove it). We used a sander and a fine-particle-filter in a shop vacuum to collect the dust, which we disposed of responsibly.
 
Jan 11, 2014
7,849
Sabre 362 113 Fair Haven, NY
Unfortunately, using a power washer to remove anti-fouling paint pollutes because the waste water drains into the local water table or system (unless there is a filter in a catch basin system to remove it). We used a sander and a fine-particle-filter in a shop vacuum to collect the dust, which we disposed of responsibly.
Our marina has a catch basin.

Even better than a shop vac with filter is a Dust Deputy. Most of the dust is collected in the bucket with the remaining collected in a bag in the shop vac. And any fine particles are trapped in the HEPA filter.
http://www.sv-secondstar.net/stuff-we-like/14-dust-deputy
 
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Oct 22, 2014
16,130
CAL 35 Cruiser moored EVERETT WA
Everett is a "Clean Water Port" in Washington. All boats are power washed by the Marina upon hoist.
 
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Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
Everett is a "Clean Water Port" in Washington. All boats are power washed by the Marina upon hoist.
John,
What are you going to do when the ban in Washington on copper AF paint starts on Jan 1 2020?
 
Jan 11, 2014
7,849
Sabre 362 113 Fair Haven, NY
Granted, I sail in shark free unsalted water, however, I've been using a copper free paint for a couple of years with good results. I do get some green stuff that washes off easily when wet or brushes off after it is dry. But no zebra mussels. The paint is Blue Water Marine Shelter Island. It did get good reviews on PS a few years ago, which is why I changed over. Also less expensive than the usual Interlux/Petit brands. Not paying for the marketing.
 
Oct 22, 2014
16,130
CAL 35 Cruiser moored EVERETT WA
Besides, If you make a run up into BC you can empty your holding tank a long the way and the sea will wash it back into the Seattle slough that comes from the failing Seattle sewer system.

Got to love Washington. They get my boat money just because I choose to sail there.