Dragon Shield Polyurea Coating for Hull Strenghtening

[sdowney717]

I was following a thread on a life raft and started to think about this polyurea.

Polyurea coating tends to be super tough, durable, flexible.
What I think is if you coat the hull with a layer of Dragon shield, it will keep the hull from splitting, say if you hit something like a shipping container, another boat, rocks, came across terrorists with heavy weapons and the keel bolts even if broken, the keel wont fall off the bottom, or if the rudder is wrenched the hull will stay together.
So as an aide to staying afloat I think this would be useful.
You can also seal up interior spaces and make watertight compartments for floatation. If you watch you will see an impressively strong and resilient polyurea coatings. even BLAST and bullet proof.

Blast & Ballistic Mitigation - Dragonshield Polyurea - YouTube

The stuff is incredibly impressively strong. I found some other polyurea hull spray videos on wooden hulls on youtube.

of course wont help if your boat is swamped etc... but maybe you can make enough watertight compartments to keep it floating.

[webejammin]

I called the folks sence there in my state of Washington and they had a bad phone connection and said they would call back in a bit. I'll report back on my conversation.
This product would help to protect our hull from logs floating on the river and possiably the tsunami floatsome from Japan like shipping containers.

[webejammin]

I called the Co and the folks sayed it is very bondable to fiberglass and could be used as bottom paint but might need wiping off ocasionally but noth growth will stick. About 1/8 inch coating would protect against the fiberglass from cracking and leaking if your boat hit floatsome like logs or bigger object like shipping containers floating just at water level. They gave me the contact of a local painting bussiness that they sell to and they apply the stuff. I wonder how it compairs to the weight of bottom paint ? My wife and I both would feel better having a product on our hull that means even if we hit a big log in our Catamaran and even if the fiberglass cracks the boat would not leak untill we were able to repair the damage with epoxy and not be repairing a hole underwater. I'll find out cost tomorrow, they are calling back.

[delmarrey]

The question would be; how would one get through the stuff to do repairs if one needed to?

And as a bottom paint, I'd like to see some test results as to sea life adhesion. Sea life will stick to fenders and rubber hoses pretty good. What makes this stuff any better?

[webejammin]

Originally Posted by delmarrey

The question would be; how would one get through the stuff to do repairs if one needed to?

And as a bottom paint, I'd like to see some test results as to sea life adhesion. Sea life will stick to fenders and rubber hoses pretty good. What makes this stuff any better?

Good question I'll ask when they call me tomorrow. I would GUESS to do an on water repair you would patch from inside the boat with the product on the outside and when reaching drydock open it up and finish the repair.

[tropicalescape]

Cool stuff..wonder what amount of weight it would add to a 30ft boat?DVC

[webejammin]

I plan on asking the weight question tomorrow ?

[sdowney717]

polyurea coatings I have been hearing more about them.
They seem ideal for coating anything. On youtube there are a lot of videos showing how it is done.

http://www.youtube.com/watch?v=uyrogrbahyQ

Polyurea-Movie - YouTube

http://www.youtube.com/watch?v=Z3SV1...F424B1BD05B504

another brick wall test shows how fast it dries and how flexible it is. A lot of companies spray these coatings around the world.

http://www.youtube.com/watch?v=1aMqy...eature=related

http://www.yachtforums.com/forums/po...l-coating.html
I found mention on another forum about Scorpion coatings which the guy says you can do yourself and Dragonshield

[Katiusha]

Looks like coating companies that market polyurea to different industries (and not only lea$ure boating), list limited marine use. There are some deep sea applications mentioned, but I couldn't find any details about that...

Some companies mention that polyurea coatings are not completely UV resistant, so they will yellow (start degrading) over time...

This is what a concrete company, http://www.concretenetwork.com/polyaspartic-floor-coatings/uses.html, says about bridge application:

On the San Mateo-Hayward Bridge, a 7-mile crossing of San Francisco Bay, all concrete beams and piles received a thee-part coating developed by Hehr International Polymers. The coatings were an epoxy sealant, a polyurea primer, and a polyaspartic top coat that provided additional protection and prevented UV-degradation of the polyurea coating. Not only has this coating system prevented any chlorides from migrating into the concrete, it has remained crystal clear and has even prevented barnacle growth.

sdowney717, you mention on WB Forum that you applied this coating almost 5 years ago. Is your boat in salt water? How's the growth? Are you noticing any UV effects?

[sdowney717]

I put on something similar made by sanitred called permaflex, not a polyurea but a polyurethane. the hull has been perfect, solid, strong, no leaks in everyway has worked except for the marine growth. Permaflex is a roll on paint on coating.

Dragon shield will be a superior coating I am sure of that in regards to everything except maybe price, and the permaflex is was fine for my use.
No way permaflex could stop bullets although I think it could stop logs from getting through.

When it first went in after a couple weeks grew a slime layer, then small amount of algae and everything easily brushed off by hand including small barnacles. I have a swim platform and could feel the bottom.

However after a year and a half the barnacles grew to full size and are not easily brushed off. You can take a wooded oak wedge and scrape them off but the permaflex does not prevent them from sticking or growing. Perhaps they stick less than without as some that I scrape come off whole and intact.

I was after really only sealing the hull, making it strong and keeping out wood worms.
The spray on polyurea looks fast and easy to do. Working with permaflex upside down is hard work.

yes boat is in salt water near LAFB in Hampton VA.
I used the aromatic not the aliphatic UV coating.
The aromatic coating will surface degrade turn chalky in direct sunlight. I cant say about the UV aliphatic version. But since this is underwater why use that?

here it is with one coat before I sealed up the seams on the keel.


here is an interior shot. The inside and outside is sealed on the boat and it is dry inside except for the rain.

[Katiusha]

Thanks for the reply. If I remember correctly, waters around you are full of living things that just love boat bottoms (and lots of war ships around). I guess no matter what type of antifouling, we still need to brush off the growth fairly frequently...

For us the worst growth was in Simpson Lagoon on St Martin - a solid layer of worms and things after 2 weeks at anchor. Took 1 day with scuba to clean the hull and another 1 day to clean the BCD velcro from all the stuff that ended up in the water...

[sdowney717]

If you used permaflex and went in to clean the hull perhaps monthly you would be able to keep up with it and not use bottom paint. The coating is glossy hard rubbery smooth slick feeling. My test though was mostly to see how the permaflex kept the hull intact and dry and secondarily how it does with growth.

Those barnacles the bigger they get the tighter they stick.

[Dkdoyle]

Ok now I am curious. If you coat the inside and outside of a wood boat how does that work? Wood boats dry out or swell up as a normal process. Normally a wood boat that has been left to really dry out is considered no longer restorable.
Would seem you could stop dry rot in it's tracks. Very interesting

[sdowney717]

Normally a wood boat that has been left to really dry out is considered no longer restorable.

Some people will actually sink the boat and let it take up.

Wood does not have to moisture cycle to work in a boat.
On my boat I removed most of the bottom planks and repaired the framing.
Coated the framing with permaflex.
Coated the inner plank side, which I think was ok, but it causes the wood to cup slightly do to swelling when the permaflex soaks in. Dont coat the plank edges, just caulk with the PL and you can mix PL with sawdust to cure in thick layers. I used a floor jack and various lengths of wood to force the planks back against the frames and also clamps.

Screwed them back on, caulked with PL Premium polyurethane construction adhesive which fills gaps and coated with permaflex. I did most of this in dry heat of summer when the planks were well shrunk.

the permaflex actually soaks into dry wood, end grain especially and the wood slightly swells but not like with water.

Hull has shown zero signs of problems and is watertight. I even have standing water in the bilge from the rain. I do occasionally vacuum out the bilge and clean with a little bleach and or flush some seawater thru. One summer I found mosquitoes nesting in there.

[Dkdoyle]

Originally Posted by sdowney717

Some people will actually sink the boat and let it take up.

Wood does not have to moisture cycle to work in a boat.
On my boat I removed most of the bottom planks and repaired the framing.
Coated the framing with permaflex.
Coated the inner plank side, which I think was ok, but it causes the wood to cup slightly do to swelling when the permaflex soaks in. Dont coat the plank edges, just caulk with the PL and you can mix PL with sawdust to cure in thick layers. I used a floor jack and various lengths of wood to force the planks back against the frames and also clamps.

Screwed them back on, caulked with PL Premium polyurethane construction adhesive which fills gaps and coated with permaflex. I did most of this in dry heat of summer when the planks were well shrunk.

the permaflex actually soaks into dry wood, end grain especially and the wood slightly swells but not like with water.

Hull has shown zero signs of problems and is watertight. I even have standing water in the bilge from the rain. I do occasionally vacuum out the bilge and clean with a little bleach and or flush some seawater thru. One summer I found mosquitoes nesting in there.

I actually think this is great. This may convince others that an old wood boat can be saved without the nasty fiberglassing the hull.