Polyurea on boat bottoms, long term

I've seen the videos of using polyurea for explosion blast protection and mitigation. As boat bottom protection on the jet boats blasting over rocks and hard obstacles. Reading about testing in the LA Harbor where no barnacles, clams mussels or animal growth attached to it, but finding a long term report is what I'm after.

I did read a forum thread where a boater rebuilt a lapstrake boat and coated it with polyurea and he reported for three years all was good. Then that was three years ago and I tried to contact him but couldn't.

I thought a six year report should tell the story.

Since the EPA is probably going to ban boating through eliminating bottom paint I was looking at the possibility of polyurea as a real alternative.

Any knowledge in this area? I'm sure there are specific brands more suited than the DIY stuff at Autozone, O'Reilly's or NAPA.

I don't have specific knowledge of polyurethane paint, but I know the EPA is seeking to ban copper, not bottom paint itself. Since copper is what makes bottom paint effective, the main ingredient is the concern. It's kind of like taking milk out of ice cream -- substitutes don't really cut it.

But there is a silver lining on the cloud. The copper in bottom paint is added in the form of cupric oxide or curprous oxide. This is a very common ingredient ceramic and glass artists use to give their work a patina appearance. The powdered form (just like the type added to paint) is available at most art supply stores that cater to ceramic artists. It's also available for $12/pound on Amazon. You can buy the new and improved ineffective bottom paint, buy cupric oxide, and add it to the paint before application.

Disclaimer: Check the laws that apply to your area before doing this.

I think WA is leading the charge on banning copper based bottom paints.....thank you all you tree huggers!

Fortunately for those of us who boat on the Columbia, Oregon has not moved in that direction.

Ed, I appreciate your information about buying cupric oxide online or at a hobby shop. Any idea on how much one should mix of that powder in a gallon of paint?

GFC said:

I think WA is leading the charge on banning copper based bottom paints.....thank you all you tree huggers!

Fortunately for those of us who boat on the Columbia, Oregon has not moved in that direction.

Ed, I appreciate your information about buying cupric oxide online or at a hobby shop. Any idea on how much one should mix of that powder in a gallon of paint?

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Take a look at the can of paint and you will see a percentage of copper noted in the specs. The effective paints have approximately 30 percent copper. I bought the cheap Petit ($90/gallon) paint and weighed the paint. I added enough copper to take it from the 18 percent specified on the can up to 35 percent. I'm assuming the percent copper indications are based on weight and not volume.

I used a paint mixing attachment on my drill to mix the copper into the paint.

I applied the paint in October of 2012. My bottom has no noticeable growth on it as of the last time I checked, which was a few weeks ago. My drive, propeller, and tabs are riddled with growth, but my boat's bottom is clean.

Hope this helps.

Capthead said:

Since the EPA is probably going to ban boating through eliminating bottom paint...

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Oh brother.

Capthead said:

I was looking at the possibility of polyurea as a real alternative.

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I guess you don't need any anti fouling properties in whatever you use on your boat bottom?

Astral Blue said:

I know the EPA is seeking to ban copper, not bottom paint itself.

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Ummm... no they aren't.

Astral Blue said:

The effective paints have approximately 30 percent copper.

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Dependant upon fouling conditions of course. In most saltwater environments in California (like where the OP keeps his boat, 60% copper is considered effective. A 30% product is worthless here.

Astral Blue said:

You can buy the new and improved ineffective bottom paint, buy cupric oxide, and add it to the paint before application.

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Simply adding copper to an existing anti fouling paint is guaranteed to be ineffective.

Bear in mind that Astral Blue keeps his boat in freshwater so take his anti fouling advice with a grain of salt.

"Simply adding copper to an existing anti fouling paint is guaranteed to be ineffective."

Why is that?

Ron

windmist said:

"Simply adding copper to an existing anti fouling paint is guaranteed to be ineffective."

Why is that?

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Because anti fouling paint is a complex matrix of binders, solvents, pigments and biocides, all designed to allow copper to move through the paint and into the water surrounding the hull. The copper has to be added to the binder during the manufacturing process, not simply mixed in to the finished product 10 minutes before you slap the first coat on the boat.

If simply adding copper powder to a cheap paint made that paint an effective anti foulant, chandlery shelves would be crowded with cans of copper powder. But they aren't.

fstbttms said:

Because anti fouling paint is a complex matrix of binders, solvents, pigments and biocides, all designed to allow copper to move through the paint and into the water surrounding the hull. The copper has to be added to the binder during the manufacturing process, not simply mixed in to the finished product 10 minutes before you slap the first coat on the boat.

If simply adding copper powder to a cheap paint made that paint an effective anti foulant, chandlery shelves would be crowded with cans of copper powder. But they aren't.

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A chandlery encouraging the mixing of chemicals that would not only void a warranty but perhaps subject the customer to civil and/or criminal sanctions is not exactly something in their interest. This is something the customer does at their own risk and they are responsible for complying with any statutes applicable to them.

Chandleries encourage compliance with manufacturer's directives and statues. This is a no-brainer.

Astral Blue said:

...but perhaps subject the customer to civil and/or criminal sanctions...

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If by this you mean that a private citizen would be subject to penalties for adding copper to the paint he bought, you really need to bone up on environmental law.

fstbttms said:

Because anti fouling paint is a complex matrix of binders, solvents, pigments and biocides, all designed to allow copper to move through the paint and into the water surrounding the hull. The copper has to be added to the binder during the manufacturing process, not simply mixed in to the finished product 10 minutes before you slap the first coat on the boat.

If simply adding copper powder to a cheap paint made that paint an effective anti foulant, chandlery shelves would be crowded with cans of copper powder. But they aren't.

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Thanks for the reply. I can understand that ablative paints may act that way but I would think that hard paints would benefit from adding copper. But what do I know?

I've also heard that adding cyan (sp?) pepper helps.

Ron

windmist said:

Thanks for the reply. I can understand that ablative paints may act that way but I would think that hard paints would benefit from adding copper. But what do I know?

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Both hard and ablative paints are designed to leach a certain amount of biocide passively.

windmist said:

I've also heard that adding cyan (sp?) pepper helps.

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Simply another wive's tale.

fstbttms said:

If by this you mean that a private citizen would be subject to penalties for adding copper to the paint he bought, you really need to bone up on environmental law.

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"Perhaps" qualifies it to be a speculative statement, in case you missed it. Feel free to borrow these, but please return them when you're finished.

I was working on my boat and just came back to this thread.

Polyurea is a spray on, roll on and brush on coating much like the truck bed liners. It can be used on the bottom of boats and is used on ships and other vessels. When you spray it on a HumVee it keeps it from blowing into pieces if it hits a roadside bomb. The marines call it Dragon Shield.

Like I said above, they tested it in the LA harbor and no growth except slime and some grass. They use it on jet boat bottoms to protect the hull.

I wasn't asking about bottom paint but if you buy a good bottom paint like Trinidad and add 4 to 6 oz roundup concentrate to it you won't get any growth of anything for a very long time.

Capthead said:

Like I said above, they tested it in the LA harbor and no growth except slime and some grass.

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Got a link to back that up?

Capthead said:

...if you buy a good bottom paint like Trinidad and add 4 to 6 oz roundup concentrate to it you won't get any growth of anything for a very long time.

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Also a wive's tale.

Capthead said:

I've seen the videos of using polyurea for explosion blast protection and mitigation. As boat bottom protection on the jet boats blasting over rocks and hard obstacles. Reading about testing in the LA Harbor where no barnacles, clams mussels or animal growth attached to it, but finding a long term report is what I'm after.

I did read a forum thread where a boater rebuilt a lapstrake boat and coated it with polyurea and he reported for three years all was good. Then that was three years ago and I tried to contact him but couldn't.

I thought a six year report should tell the story.

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I brought up a subject thread on Polyurea over here, but it didn't get much play:
http://www.trawlerforum.com/forums/s3/polyurea-coatings-boats-blast-ballistic-mitigation-11619.html

There is a Polyurea applicator that talks about the product(s) over here:
Polyurea Coatings - Boat Design Forums

That other forum also documents a few fellows that have experimented with it as an anti-foulant. I can't remember where those links are at the moment, but a 'search' of that forum should bring them up,....or a google search.

Antifouling Discussions

brian eiland said:

That other forum also documents a few fellows that have experimented with it as an anti-foulant. I can't remember where those links are at the moment, but a 'search' of that forum should bring them up,....or a google search.

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Here are two lengthy discussions of anti-fouling solutions that somewhere in them also contain references to polyurea:

Barnacle Prevention - Boat Design Forums

New antifoul discovery - 100% effective AND green - Boat Design Forums