Urethane coatings

[bagarre]

http://www.skinboats.org/#!urethane-application-/c1xub

 

Has anyone here tried to trowel on urethane like this?

It reminds me of spreading epoxy or other semi-viscus materials.

[bagarre]

I talked to the guy over at skinboats about their goop and decided to go that route.

They worked out a new application technique with foam rollers vs the squeegee which greatly simplifies the process.

He said his first time students are applying it with a foam roller better than he can with a squeegee. - We'll see.

 

With the dye mixed in, it provides the translucent look.

[Action Tiger]

Sorry, bud, no experience whatever.

I have always only used paint or varnish.

Peace,

Robert

[bagarre]

I'll be sure to post my findings.

[Kudzu]

Never tried it but it is a proven product on nylon. I see no reason it wouldn't stick to polyester. For a boat that could see some rough use, I think it might be worth while.  But I don't baby mine and oil based paint has proven itself over and over so I never saw a reason for the extra cost. Plus I have mixed feelings about the looks of it.

[bagarre]

The look was the one thing I wanted. My wife saw a photo of a red stained nylon boat and fell in love with it.

 

At first, I was going to buy the color and just tint a clear urethane but I worried about UV protection and cracking and decided to go with a proven system.

 

If you're not into the look of a stained boat, I agree that oil based paints are plenty durable.

[Abyssdncr]

I used spar varnish on the last one for the kiddos. Got that translucent look we were going for and it filed up the 6 oz economy fabric wonderfully. 4 coats on the bottom, 3 on the top - not a single leak one.

[bagarre]

Results are in and lesson learned. This stuff is plain miserable to work with and instructions are pretty useless. 

Using a foam roller may be easier than the squeegee method but it's a pain to push into the fabric and each subsequent coat has a constellation of air bubbles.

The product is thicker than epoxy and doesnt roll well - at all.

Pot life is about 15 minutes before it really gets gooey.

 

I ended up cutting it 10% with MEK and using my gun to put another dusting of MEK after application to keep the bubbles down but, they are still there.

3 days and I'm not done with the bottoms.

I'm tempted to call it a loss and just paint the decks but the final translucent color is what we were going for.

 

[Action Tiger]

Well, why do anything the easy way on these two, eh? You've put in a tremendous amount of effort, and it is truly paying off.

I love the little paw prints.

Peace,

Robert

P.S. I once did a cotton duck covered boat that I coated with a few coats of orange shellac, then sealed up with varnish. It looked a lot like real skin.

[bagarre]

Thanks. I'm really enjoying the build but the finish introduced a level of frustration I wasn't prepared for.

 

We're contemplating a regular urethane varnish on the decks vs risking it with the goop.

The two tone would look nice and the lighter decks would stay cooler in the sun.

 

The paw prints were my wife's idea. I plan to have more fun topside. 

I'm getting pretty good at drawing these little guys with a sharpie. The fabric bleed actually makes it look a bit more authentic too.

 

[Action Tiger]

So, after those coaming builds, you weren't prepared for frustration? I know what you mean, though. These things are done, and it's time to paddle! The finish on my baidarka is coming along better than I hoped, but also slower. Intricate paint schemes almost always do...

The sharpie idea is brilliant. I draw on everything with sharpie, but never thought of cloth on a boat.

Well, no I for sure have to build a castaway. Then I can draw a Chinese carp on the skin with all the scales and all. Oooh...

Your boats look great, and two tone would be super cool...

Peace,

Robert

[flynfysh]

looks great to me...I feel your frustration though...the paint I'm using either is too light and leaves holes or fills the holes and then drips, I can't seem to find a middle ground..I am helping to keep the sandpaper manufacturers employed, though

 

In the end we are always our own worst critics..my friends rave over my first boat....I see a hundred places it needs improvement

[davidd]

I just used the skinboats.com urethane on a boat that I am building using the new 8 oz polyester.   Over the years I have built about a dozen wood strip canoes and have lots of experience with polyester, vinylester, and epoxy resins.  The urethane was a true pain to put on. I used a combination of 4” foam roller and plastic squeege.  As the product cured a lot of small air bubbles appeared.   I suspect they were caused by air that got pushed into the fabric during the application process.   I am tempted to rip the fabric off and to start over but will paddle the boat first to see if I like it.

 

On a related topic there seems to be a lot of discussion about oil vs latex paints.  While nothing beats a very high quality oil paint for painting interior house trim, there is a whole new generation of paints that have been formulated in recent years that have low VOCs but the toughness and look of oil.   One I personally have experience with is Benjamin Moore Advance paint.   It is a water base paint that can be brushed or sprayed.   Much tougher than any latex paint.    Does anyone have any experience with it for a SOF kayak?

 

David

 

 

[Kudzu]

I hear basically the same stories about applying Cory's Goop over and over. Lots of stories about how hard it is to apply so I have never tried it because of the stories. Was a afraid I would be disappointed and and do exactly what you are talking about. Ript it off and redo.

 

My only experience with latex was a few years ago and it wasn't good. It didn't soak in the fabric well. It just sat on top of the fabric and eventually was scrubbed off in places and started to seep.  I never tried it again but I am sure they have gotten better but not sure if they work well on boats. If it is thinner than it was that would probably be a good thing. It would soak in the fabric.

 

Of course you can always go to Kirby Paints and get a good oil based in a lot of colors. That is what I will have to on new boats I build for anyone.

[FERNANDO]

i used this technique on my ravenswood with nylon cloth, good results not that difficult.

 

https://www.youtube.com/watch?v=Ogpa14Xo1yk

  

[Hirilonde]

On 5/28/2019 at 7:40 AM, Kudzu said:

Of course you can always go to Kirby Paints and get a good oil based in a lot of colors. That is what I will have to on new boats I build for anyone.

 

Kirby will make custom colors.  Just call them up.

[Scott Pettigrew]

This is an old thread, but I have a urethane question I didn't see addressed.  Can you apply a coat of urethane over a fully cured coat?  I know with epoxy this is a no no without sanding.  I'm think that even after 3 coats I may want to come back and do some touchup.  Will a new coat adhere if the underlying coat is fully cured?  I'm using the 2-part urethane from the Skin Boat Store.

 

 

[Scott Pettigrew]

I'm adding my experience with the two-part urethane as it might help someone in the future.  As Jeff mentions in his book, getting the mix right is critical.  I've applied gallons of two-part epoxy and never had any trouble, but the urethane is much more sensitive to having too little of part A, the hardener. 

 

After applying 3 coats to the hull and waiting 72 hrs, the urethane was still slightly tacky.  To remedy the situation, I mixed up one more batch but went slightly heavy on part A, roughly 4oz of Part B to 2.5 oz of Part A.  This did the trick, and the urethane fully cured in about 24 hrs.  

 

I think what happened initially is that a disproportionate amount of Part A was remaining inside the measuring cup because it's more viscous that Part B.  When I flipped the boat to do the deck, I measured a smidge higher on the Part A and also used a stir stick to scrape the inside of the cup and make sure I removed as much as reasonably possible. 

 

Lesson learned: Measure carefully.  Get all of the stuff out of the measuring cup.  And if you are going to err, err on the side of too much Part A.