I’ve searched to see if there is anything on here, but when i put the words polyurethane and epoxy together all i find are the same polyester/polyurethane vs. epoxy/eps arguments…i know that it can be done, but what is the end result??
I’ve built several…
You get a board that takes longer to build, but is less toxic to the builder and environment, but not significantly lighter or stronger than a pu/pe. Keep it clear, with no tints or pigments or paint, use good quality epoxy (RR), and the average Joe won’t be able to tell the difference.
G’day Jimmy,
check this thread http://www.swaylocks.com/forum/gforum.cgi?post=343714;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread
Regards
Daren
excerpt from:
http://www.swaylocks.com/resources/detail_page.cgi?ID=1029
the epoxy is safe as peanut butter legend in the making
Quote:
Greg Loehr – Monday, 10 November 2003, at 9:05 a.m.
Here are some of the advantages.
Epoxy is stronger so the board comes out stronger with better resin
Since epoxy is stronger it takes less resin in the laminate to do the same job as polyester.
And epoxy has a slightly light specific weight.
This makes a lighter board even with the same blank used for the poly.
In fact with epoxy on Clark foam you can use a green blank and it will come out the same weight as the same glassed poly lamination using a blue.
And MUCH stronger.
You can laminate ANY foam with epoxy. Not just urethane.
This gives you the option of making your own blanks.
Our new epoxy system as fast as MEK initiated poly so production times are quicker than in the past.
Cosmetically epoxy is clearer making a whiter board. Yellowing is also slower than with poly.
Epoxy can be cleaned up with soap (GoJo type) and water. There is no need for clean up solvents.
Our Epoxy has very little vapor (odor) so work can be done almost anywhere. No masks are necessary with just moderate ventilation.
You use approximately 1/3 the amount of epoxy resin to build a board as you would polyester.
These last three, immediately above, give you an indication of the reasons epoxies are better for the environment and for labor.
Epoxy gives the laminator more work time and there is no real “gel” time to catch you.
The resin just gradually thickens as it begins to harden. This allows a higher quality laminate.
All the newer fabrics (Kevlar, carbon, s glass, etc.) were designed for use with epoxy.
Not surprisingly, they all perform best in an epoxy matrix.
On the health issues, with our epoxy (Resin Research), I have never seen any sensitization that doesn’t involve a co-toxin. The one in particular in our business is acetone. It serves as a vehicle for toxins through the skin. We eliminated acetone from our shop long ago and have never had any problems. We now use soap and water, which work better anyway. Our resins also do not contain phenol or formaldahyde, which many other systems do. These are some other co-toxins I mentioned above. Also our hardeners are based solely on cycloaliphatic diamine technology as opposed to straight chain amines. This also reduces toxicity. We also have safeguards built into our formulations to reduce toxicity. This makes our hardeners much safer to use than most other epoxies.
Epoxy Safety Issues
Toxicity. Vapor from most epoxies is much lower than it’s polyester counterparts. The resins we produce (Resin Research Epoxies) are all high solids and have 1/50th the vapor of polyester surfboard resins. In our shop (which is well ventilated) we don’t even wear masks.
Epoxy is also NOT a carcinogen.
That has been well proven by OSHA and many others in industry.
What epoxy is, is a skin sensitizer.
This varies greatly between different epoxy systems depending on different company’s formulations. Most older epoxy hardeners are formulated with a chemical known as TETA or another called DETA. These base hardeners are in the aliphatic amine family, are very reactive, somewhat unstable, quite toxic and easily can cause sensitization of the skin (or dermatitis). Most of these hardeners are also modified with phenol and formaldehyde. Phenol is what dermatologist use for chemical skin peels and increases TETA and DETA’s toxicity to the skin dramatically. Many of these older hardeners are up to 50% phenol. Formaldehyde is also no picnic as it also increases risk because of it’s ability to act as a vehicle for the phenol and amines through the skin and into the blood system. By the way, the reason these epoxy hardeners are still used today is because they’re CHEAP. DETA and TETA cost 1/5 what a modern diamine based hardener costs to produce. Anyone who has worked with many of the West System epoxies are familiar with these low cost systems.
Modern epoxy hardeners are nothing like their 60’s counterparts. As I mentioned above, they are formulated with modern diamines and have vastly reduced incidences of sensitization. They also have lower vapor, better color, better finish, and lower exotherm. They contain NO phenol and NO formaldehyde. Our company was one of the first in the US to formulate and market diamine based epoxy hardeners 20 years ago, which gives us an edge in experience with these chemicals.
As superior as they are they still must be respected as skin sensitizers.
The simple way to eliminate problems related to dermatitis in the workplace is to reduce or preferably eliminate contact with the skin.
This means gloves.
That’s it. We wear disposable vinyl gloves.
Vinyl is preferable to rubber because rubber gloves are also skin sensitizers.
The other, even more harmful, ingredient is contaminated acetone. Like formaldehyde above it is a vehicle for toxins into the bloodstream.
Fortunately epoxy can be cleaned up with soap and water. Not standard bar soap but with products like Go-Jo and Fast Orange. These products are water based and don’t act as a vehicle the way VOC solvents do. In 20 years of producing epoxy surfboards we have NEVER had one incidence of dermatitis in our shop. I have also NEVER seen a case of dermatitis that didn’t have something to do with the co-toxin acetone. Given the aforementioned resin parameters and if shop practice adheres to the above suggestions, epoxy resins are MUCH safer to use for producing surfboards than their polyester counterparts.
I do it all the time. I have 7.5 gallons of 2 to 1 epoxy from Fiberglass Hawaii that I have use up. UV resin is so much more easier and faster on PU blanks.
End results: about the same but it takes longer to do compared to PU/PE. Perhaps a bit stronger. The polishing takes longer to get it super shinny.
Yes. Stronger and much easier to work with, but you can’t UV cure it.
yep ,
my 9’ mal
unfortunately it snapped in half 6 months later
it is now fixed and back in action though
cheers
ben
I have made a few boards with poly blanks and RR epoxy with good and not-so-good results. One was a Walker blank with 6 oz cloth and a yellow resin tint, came out very strong with no denting. Another one I made used a Clark blank with Volan glass and I have experienced significant denting on the deck. Only real diff between the two boards is that one was constructed during hot 80+ summer weather and the other was put together in a cold 55-65 degree garage in the winter.
Will make others but will pay attention to the temps.
I think the biggest difference you have there is Walker and Clark. Clark blanks get very soft very quickly if you plane anything more than a little off them in my experience.
yup…done a few with good results…including some with pigment…seem stronger than pe, and definitely easier on the braincells/environment…gotta love the gojo cleanup…
I made a bunch of boards this way when I was living in Florida and had a shop in my garage, which was connected to the house. I could glass in there with epoxy, but if I would use polyester - it would infiltrate the whole house! In the Florida summer, It did not take much longer to build a board with epoxy. In the winter, I would just heat up the garage with a space heater when I was glassing. I did all kinds of tints - you have to be careful with color because it can get cloudy but a lot of the colored resin jobs came out great. Airbrushing doesnt look so hot with an epoxy glass job.
The boards turn out great - at first. For the same strength, I could make them a little lighter and they would be much more ding resistant. BUT after about a year, the foam starts shrinking and the stringer, logos, finboxes, and pour lines in the blank raise up. This happened withevery board I built this way (probably about 50). All these were with Resin Research and Clark blanks. Greg Loehr (who makes Resin Research) posts here and says that epoxy on polyurethane is a good way to go, but I have never read him address this problem…
Just one thought. As a very novice glasser, I used the slow 50 minute cure RR thinking i would like the extra time. I found that way too long to set up properly and hated coming back to the board and hour later - hell two hours later - and realizing the stuff was still gooey. Hot coating with that stuff was a joke. You could kick the stuff, go watch a seinfeld rerun before coming back and hotcoating and it still took way too long to gel.
I only use the 25 minute stuff now.
i’ve done several…most all with tints…works out just fine.
Quote:
I made a bunch of boards this way when I was living in Florida and had a shop in my garage, which was connected to the house. I could glass in there with epoxy, but if I would use polyester - it would infiltrate the whole house! In the Florida summer, It did not take much longer to build a board with epoxy. In the winter, I would just heat up the garage with a space heater when I was glassing. I did all kinds of tints - you have to be careful with color because it can get cloudy but a lot of the colored resin jobs came out great. Airbrushing doesnt look so hot with an epoxy glass job.
The boards turn out great - at first. For the same strength, I could make them a little lighter and they would be much more ding resistant. BUT after about a year, the foam starts shrinking and the stringer, logos, finboxes, and pour lines in the blank raise up. This happened withevery board I built this way (probably about 50). All these were with Resin Research and Clark blanks. Greg Loehr (who makes Resin Research) posts here and says that epoxy on polyurethane is a good way to go, but I have never read him address this problem…
I built a (knee) board in 1973 using Clark foam and epoxy resin. On occasion, I still ride it. The foam hasn’t given any indication of shrinking nor has the stringer raised up. Perhaps the difference between our two experiences relates to differences in foam density.
mtb
This board was built late last year. The picture was taken during the Oxbow Pro late spring this year. The board has held up fine. Just Foam glassed with Epoxy.
Sure…I’ve done epoxy with tints, pigments, paint… even resin drizzles and swirls. And I agree… they come out just fine.
But you can tell the difference between epoxy and poly in all of them. It’s just a different look, for sure. I happen to like it just fine. With no color, however, two new, fully cured boards next to each other, it’s difficult to tell what’s which.
As for strength… The only PU I’ve ever done with epoxy is Clark and Excell, and I would still argue the difference in strength and weight, all other things being equal except the resin, is insignificant.
Quote:
……
As for strength… The only PU I’ve ever done with epoxy is Clark and Excell, and I would still argue the difference in strength and weight, all other things being equal except the resin, is insignificant.
What I meant by differences in foam density is that Clark blanks back in the early 70’s were generally of a greater density foam than typically used in later blanks. Also the Clark foam at that time was more uniform in density throughout the blank, rather than “skinned” with a higher density near the surface.
By Jan 1 RR will have a urethane specific epoxy on the market called RR CE. There have been some problems in using epoxy over urethane in the past which we have now worked out. This includes some modulus issues, some UV issues and some resin ratio stuff. In short, the new resin will allow you to laminate a 6 double 6 on urethane for the same weight as a 4 double 4 of polyester resin. We changed a couple things which allow for a much higher fabric content in the laminate with (of course) means a lower resin content resulting in an aproximate strength advantage of 200% at a given weight. Resin use will be less than 1/3rd of polyester making this resin more economical to use than polyester. It will reduce waste by about 90%, reduce VOC emmissions by 98%+, and reduce resin use by 70%. No clean up solvents are nessasary. The environmental aspects of this chemistry is unprecideneted. It will contain an optical brightner and a UV absorber which will protect the urethane from breaking down which is one of the things we’ve seen before this chemistry. Stronger, lighter, cheaper, better cosmetics, better environmentally, no EPA or SCAQMD issues.
According to what I’m hearing the hammer is about to come down on polyester chemistry again in SoCal. This answers also all those potential problems without everyone having to use EPS exclusively.
and when/if / will it be available in australia? has any thing been done about distribution of RR here
We have been selling to Seabase Australia for almost a year. They are in brisbane and the contact info is on our website at resinresearch.net