epoxy waterproof

x8rider · Post by **x8rider** » Mon Apr 14, 2008 2:49 pm

I'm new to building and am going to start this summer. I was wondering if the epoxy that you use for a snowboard is waterproof. I know that companies have started introducing cloth topsheets to reduce weigh. Thanks for the help!

doughboyshredder · Post by **doughboyshredder** » Mon Apr 14, 2008 3:31 pm

Epoxy is not waterproof. After the snowboard is built you have to waterproof it with urethane. All of the major manufacturers do this. That's why it's so important that you don't let anyone in the lift line scratch your snowboard.

x8rider · Post by **x8rider** » Mon Apr 14, 2008 6:43 pm

so they literally cover it with a urathane? Thats interesting because i was wondering how people stopped it from getting warped and water logged, so even a regular topsheet isn't waterproof?

G-man · Post by **G-man** » Mon Apr 14, 2008 7:38 pm

I'm not sure what's gotten into doughboy lately (other than a bit of sarcasm... see http://www.skibuilders.com/phpBB2/viewtopic.php?t=1313), but, for clarifications sake and so as to not unnecessarily mislead other new builders, epoxy resin is, in fact, very waterproof and does not need to be top coated with polyurethane. Epoxy is, however, not UV resistant, so any ski that does not use a top sheet does run the risk of UV degradation of the exposed epoxy. So, in this case, a top coat of PU is a good idea because PU does contain a chemical UV blocker and will protect the underlying epoxy.

If you choose to build using exposed wood sidewalls, it's also a good idea to coat the exposed wood with PU to prevent water absorption. The UHMW topsheet material is completely waterproof.

G-man

Greg · Post by **Greg** » Tue Apr 15, 2008 8:15 am

For further confirmation of the fact that epoxy is waterproof, just ask yourself... would you build a boat out of epoxy and fiberglass if the end product wasn't waterproof?

endre · Post by **endre** » Tue Apr 15, 2008 8:23 am

Greg wrote:For further confirmation of the fact that epoxy is waterproof, just ask yourself... would you build a boat out of epoxy and fiberglass if the end product wasn't waterproof?

..or a ski?

x8rider · Post by **x8rider** » Tue Apr 15, 2008 8:33 am

true haha, i just wanted to make sure before i started experimenting with something that was failed. also, i figured i'd ask, but does the topsheet add any rigidity (stiffness) to the board?

Greg · Post by **Greg** » Tue Apr 15, 2008 8:39 am

It probably adds a little bit of rigidity, depending on what it is made of. It also could add a fair bit of damping. Mostly my experience has been that topsheets just add weight though.

x8rider · Post by **x8rider** » Tue Apr 15, 2008 10:22 am

that's why i want to try the cloth topsheet that ride came out with this year. that's why i wanted to know if epoxy is waterproof because if you could make your topsheet out of cloth, it would be much lighter and probably keep teh board super flexible (i'm a park rider so the more flex/pop the better). I was thinking about giving it a shot and if it works great if not, then i guess it's just another idea down the toilet lol. any imput from anyone about my idea?

G-man · Post by **G-man** » Tue Apr 15, 2008 11:35 am

Regardless of whether you use a plastic top sheet, a cloth top sheet, or no top sheet, you'll not be able to tell the difference in the way the skis ride. The ride characteristics come from other things. If, however, you want to go with a cloth top sheet rather than plastic, you'll need to use a non-bondable smoothing layer on top of your lay-up so that the top surface of your skis come out smooth. Then, it would be a good idea to top coat the skis with a brushed or sprayed on coat of polyurethane so that the epoxy is protected from UV degradation. I think hydrant71 submitted a great picture of a snowboard that he did a year, or so, ago, in which he used this technique... turned out very shiny and smooth.

G-man

jono · Post by **jono** » Tue Apr 15, 2008 4:44 pm

Veneer top sheets look great and add very little weight.

x8rider · Post by **x8rider** » Tue Apr 15, 2008 6:11 pm

that's what i thought, i'm just going for weight saving here. I mean, why use a bulky topsheet when you could use cloth. I figured i'd have to polyurethane it in order to keep it from degrading. I figure it would add a custom touch to the board because i'd have a board that no one else would have. Thanks for the imput, now I just have to figure out what to use to press the board so that it doesn't end up sticking to the mold, if anyone has done this, sugestions would be greatly appreciated.

x8rider · Post by **x8rider** » Thu Apr 17, 2008 4:57 pm

ok, now my last question is, if i'm using a cloth topsheet, how will i get the top edges of my board to stay waterproof. I can't seem to figure it out, but where your sidewall stops you would have exposed wood, and since it will be my first build I don't want to get into tip and tail spacers yet, i'd rather just do a full wood core. If i'm using rubber dampening, if i put a strip of it across the top and the bottom (i saw this done in the folsom customs video on youtube, which the link is on this site) will that work to seal it off so that i don't have exposed wood on the tip and tail?

jono · Post by **jono** » Fri Apr 18, 2008 6:06 am

After you have routed/sanded your skis to their final shape you should hit any exposed wood and epoxy (this includes your epoxy soaked cloth top sheet) with a couple coats of spar varnish. This provides good UV resistance and waterproofs everything nicely.
I've noticed that varnish doesn't always dry quickly when it is applied to uncured/curing epoxy. Let the epoxy cure for a few days/a week at a good temperature (70F +) before applying the varnish.
Good luck on your first pair!

endre · Post by **endre** » Sun Apr 20, 2008 1:21 am

Hey Relax dude! There is no way your skis will ever soak up and rot, delam or even look bad because of water. From 100 000 years ago up to 30 years ago, skis were made of wood only. I have got skis with poplar (softwood) sidewalls, they have been used for summer skiing in slush and rain, there is no trace of water damage to the wooden sidewalls. Even boats are made of wood.

The problem with soft wood and water is where the wood don't get the chance to get dry (a wooden wall can rot faster
if you paint it). This is why a wooden core can rot in the screw holes under a binding. But if you don't treat your skis like shit you will never have a problem even with fully exposed sidewalls.

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epoxy waterproof

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