S3 WR LPU??

Can this be used instead of varnish over conventional glassed epoxied deck.

https://www.systemthree.com/products/water-reducible-linear-polyurethane-topcoat


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RE: S3 WR LPU??

Seeing who it's marketed by, I can't fathom why it couldn't be... but with the prices they're asking I'd certainly put your question to them before I bought any.  

RE: S3 WR LPU??

It absolutely can. I used the stuff on my Brand X sailing dinghy and it turned out great. It's held up for a bit over 11 years so far.

The only thing to watch out for is that I've read some reports from builders who've used the unpigmented clear coat version who said that the finish wasn't as clear as a good marine varnish. I haven't used the clear coat myself, so I can't give you a first hand report on that, but the pigmented products are great. I wish CLC would carry them.

S3 sells small sample jars, you might want to get one and see how it looks clear.

But it is totally compatible, good-looking, tough and lasts a long time.

Laszlo

 

 

RE: S3 WR LPU??

   Thanks for your replies.

One thing though UV protection I don't see any mention on that.

I'd be going over STAINED  glassed epoxy deck??

RE: S3 WR LPU??

From the page your link above led me to:

"WR-LPU contains UV absorbers and will not yellow or lose gloss for years, depending on exposure."

So it gets mentioned yet lacks details. That caveat about 'depending on exposure' makes me think full-sun's probably going to shorten its lifespan, but compared to traditional varnish? No idea.

Over stained substrate you're limited to the unpigmented product so that's another factor to consider: whatever UV protection it provides will be on the shorter side of the curve.

RE: S3 WR LPU??

Another thing I'd ask about would be repairability. If you use the cross-linked formulation for your initial coverage, can you use the stuff w/o cross-linker added for repairs? Adding cross-linker likely shortens the shelf life of the product that's left over.

If you opt to leave the cross-link additive out the resulting finish isn't as durable, but does that also reduce whatever UV protection you'd otherwise be getting?

How does the cross-linked formulation compare to the non cross-linked when it comes time to effect a large scale repair where the stuff needs to be removed? Or either formulation to traditional varnish?

May want to ask these or other questions of the S3 folks to get a better understanding of how their product behaves in use.

RE: S3 WR LPU??

The clear coat has UV protection. As spclark says, for specifics you need to talk to S3.

The cross-linker is a tiny bottle of stuff that comes with the topcoat. You literally add a few drops to what you poured into your container, stir it in and apply the topcoat.

The cross-linker does not affect the UV protection, it simply makes the topcoat much harder by causing the LPU molecules to cross-link to each other. Without the cross-linker the topcoat cures to a nice, durable finish. With it it's very tough and scratch-resistant, and more difficult to sand. You'll be less likely to need to fix a scratch, but when you do it'll be more work. Standard practice is to do the first few coats without cross-linker so you can wet-sand out brush marks and drips, then to add the cross-linker to the last coat. Since I didn't spray, I didn't pay much attention to the instructions for that. They're available on the S3 website.

Since the LPU is epoxy-compatible, as long as you've covered the stained wood with epoxy there should be no stain compatibility issues.

Laszlo

 

RE: S3 WR LPU??

SWMBO wants a color, burgundy, that only seems to be available in Pettit EZPoxy. Any idea how Pettit EZPoxy polyurethane with its cross-linker ("EZ Poxy Performance Enhancer 3021") compares to the System 3 poly and cross-linker? 

RE: S3 WR LPU??

Never used Pettit, but I'd be really surprised if they weren't equivalent.

Laszlo

 

RE: S3 WR LPU??

   @ Laszlo 

What color is that, Vashon gray semi gloss??
It looks like a silver but I don't see that in the color chart?
Thanks PP

RE: S3 WR LPU??

 I used the S3 WRLPU clearcoat 7 years ago, and I think it is more clear than varnish. (I think  Interlux makes a 2 part PU "varnish" but I was familiar with the fumes and wanted to stay away.)

I'm not an expert with either, although I have used varnish many times, and only this one time with the WRLPU. I didn't end up with as smooth a finish with the WRLPU as I have with varnish, but that was probably lack of both humidity and especially experience. Learning curve and all.

I used the cross linker and heard that the end result is more durable than varnish. Don't know about repairability issues ; now that I think about it, I did recoat the sole where my feet and the fuel tank had scraped the finish. Seemed to do fine. I want my boat to look good, but it's not a piece of furniture-- I use it!

 

 

RE: S3 WR LPU??

It's not in the color chart because it's my own custom mix.

I started with white, added blue and then darkened it up with just a touch of black. Somewhere I used to have a notebook with the exact proportions but at this point I'm not sure where (it's been almost 12 years).

I picked that color for the interior to keep it from heating up in the summer and to reduce the glare that a white interior would have.

Laszlo

 

RE: S3 WR LPU??

   Laszlo, thanks for the reply but shucks I was hoping it was something right out of the can.

I'm considering abandoning my oxblood red stained deck for a paint color due to too much  weave visibility along the edges and seams. It's a MC 13. The amas on my sailrig are deck oxblood with white hulls. They came out great.

The yak will be white hull also so I thought a silver/gray deck with black striping would be nice. Keeping just the hatches oxblood red. 
So back to the drawing board!

PP

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