Epoxy & UV Protection
Epoxy & UV Protection
Does anyone make an epoxy that has it's own UV protection? If not, why not? It would save so much time and effort with varnish.
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Patricks Dad
- Posts: 1476
- Joined: Wed Oct 13, 2004 1:11 pm
- Location: Warrenville, Illinois
West System 207 is claimed to include UV protection but I've never seen anyone suggeest that it is sufficient by itself....
From West System's website:
An ultraviolet inhibiting additive improves the resistance of a WEST SYSTEM 105/207 mixture to sunlight, but the cured epoxy surface will still require the additional protection of a quality UV-filtering varnish.
Not sure why some chemist can't put the whole solution into one cocktail...
From West System's website:
An ultraviolet inhibiting additive improves the resistance of a WEST SYSTEM 105/207 mixture to sunlight, but the cured epoxy surface will still require the additional protection of a quality UV-filtering varnish.
Not sure why some chemist can't put the whole solution into one cocktail...
If they ever do, we can be sure it will be more expensive than buying epoxy and varnish. -
Glen Smith
- Posts: 3719
- Joined: Sat May 08, 2004 9:08 am
- Location: Baie-St-Paul, Quebec, Canada
Randy is right about the West 207 claim.
This info is from MAS: "MAS Slow Hardener is a phenol-free, modified amine, epoxy resin hardener. When used in conjunction with MAS Epoxy Resin it provides high reactivity and an extended gel time which allows for controlled application periods. Special features exhibited by this product include blush free surfaces, good ultraviolet stability, smooth finishes in cured films, excellent osmotic resistance, and the ability to cure under high humidity. MAS Slow Hardener is intended for use with MAS Epoxy Resin and can be applied in a diverse range of conditions where increased working time is required. We highly recommend formulations of MAS Slow Hardener when large surfaces are to be coated or laminated. Slow formulation cure blush free and eliminate the need for time consuming wash downs during on-going laminations or repetitive build coats. The low viscosity of MAS Slow Hardener (200-250 poise) when mixed with MAS resin is ideal for fast wet-out of reinforcing fabrics."
I haven't seen this UV protection claimed by others. But you still have to lay on the varnish for good UV protection. This said, may last kayak spent 5.5 months last year out in the elements and it still hasn't been varnished. The epoxy on this boat is mainly Citadel epoxy but the final coat is West 105/207. I guess I should varnish it before this year's launching.
This info is from MAS: "MAS Slow Hardener is a phenol-free, modified amine, epoxy resin hardener. When used in conjunction with MAS Epoxy Resin it provides high reactivity and an extended gel time which allows for controlled application periods. Special features exhibited by this product include blush free surfaces, good ultraviolet stability, smooth finishes in cured films, excellent osmotic resistance, and the ability to cure under high humidity. MAS Slow Hardener is intended for use with MAS Epoxy Resin and can be applied in a diverse range of conditions where increased working time is required. We highly recommend formulations of MAS Slow Hardener when large surfaces are to be coated or laminated. Slow formulation cure blush free and eliminate the need for time consuming wash downs during on-going laminations or repetitive build coats. The low viscosity of MAS Slow Hardener (200-250 poise) when mixed with MAS resin is ideal for fast wet-out of reinforcing fabrics."
I haven't seen this UV protection claimed by others. But you still have to lay on the varnish for good UV protection. This said, may last kayak spent 5.5 months last year out in the elements and it still hasn't been varnished. The epoxy on this boat is mainly Citadel epoxy but the final coat is West 105/207. I guess I should varnish it before this year's launching.
Thanks guys,
That's some interesting information.
Randy, I agree with you on the chemist. They should be able to figure out a way to put everything in one cocktail.
Doug, That was great info you pointed me to. Tha's quite a study. They must have taken some of Glens advice with the test panel. (Just kidding you Glen)
fz7m0d, You are probably correct about the cost, but I would gladly pay it if it worked. I think many others would also.
Glen, I am using MAS epoxies, but had never read this information. Thanks, it is a little encouraging to read such a claim. I do worry about UV protection and after reading the study at oneoceankayaks, I became even more concerned. I agree, after todays reading, you should varnish the yak real soon.
That's some interesting information.
Randy, I agree with you on the chemist. They should be able to figure out a way to put everything in one cocktail.
Doug, That was great info you pointed me to. Tha's quite a study. They must have taken some of Glens advice with the test panel. (Just kidding you Glen)
fz7m0d, You are probably correct about the cost, but I would gladly pay it if it worked. I think many others would also.
Glen, I am using MAS epoxies, but had never read this information. Thanks, it is a little encouraging to read such a claim. I do worry about UV protection and after reading the study at oneoceankayaks, I became even more concerned. I agree, after todays reading, you should varnish the yak real soon.
The reason that UV inhibitors are not added to epoxy in sufficient quantities to negate the use of additional coatings which contain larger amounts of UV inhibitors, such as spar varnish, is that UV inhibitors are sacrificial in nature. As they do their job of absorbing UV rays, they are broken down and wear out. So at some interval, even the UV coating has to be replenished by adding more coats. You often see this breakdown of the coating as a chalk film on paint, varnish, etc. that occurs over time, such as on your car. If a car gets old enough and the paint is exposed enough to sumlight, it will have to be repainted. However, a canoe or kayak is different in that the epoxy is a structural element and is much more difficult to replace. The easier way to deal with this is simply to protect the epoxy to begin with and continue to protect through regular recoating of the UV inhibitor. I suppose if a person didn't care whether the canoe lasted more than 10 years or so, depending on the amount of exposure to UV, one could simply just leave it unprotected and replace the canoe when the epoxy failed.
System 3 also makes an epoxy with some UV protection , their SB-112. It's still a good idea to use a UV absorbing varnish.
Another reason not to put UV absorbers in the epoxy itself is that you need to protect all the epoxy. That means you need to filter out the UV before it penetrates, so only the part of the UV absorbers that are right at the surface are useful. Since they are expensive, and might affect the epoxy strength, why waste them?
Another reason not to put UV absorbers in the epoxy itself is that you need to protect all the epoxy. That means you need to filter out the UV before it penetrates, so only the part of the UV absorbers that are right at the surface are useful. Since they are expensive, and might affect the epoxy strength, why waste them?
Alan
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Jerry in Wisconsin
- Posts: 5
- Joined: Mon May 10, 2004 2:25 am
- Location: Delafield, Wisconsin
For the past couple of years I have been using 303 Protectant on my canoe.
http://www.303products.com/main.php?infopage=protectant
It has worked well on my plastic kayak and my truck cap. I have had no problems with the striper canoe. I put it over the varnish.
The upside is that it takes about 15 minutes to put 303 on your boat. The downside is that the instructions say to add it about every 30 days. I have been putting it on about 4 – 5 times each summer. You don’t use very much. A quart lasts me about one summer for 2 boats and my truck cap.
The 303 makes the surface very slick, so if the inside of your canoe is sanded smooth, you might not want to use it on the interior of the boat.
http://www.303products.com/main.php?infopage=protectant
It has worked well on my plastic kayak and my truck cap. I have had no problems with the striper canoe. I put it over the varnish.
The upside is that it takes about 15 minutes to put 303 on your boat. The downside is that the instructions say to add it about every 30 days. I have been putting it on about 4 – 5 times each summer. You don’t use very much. A quart lasts me about one summer for 2 boats and my truck cap.
The 303 makes the surface very slick, so if the inside of your canoe is sanded smooth, you might not want to use it on the interior of the boat.