Least Yellowing Epoxy

I think someone did a test on this a while back but I can’t find it. Can anyone assist?

Hey Deanbo,

Out of the few epoxies I've used ATL Kinetix stays the clearest the longest. It still goes yellow but nothing like the FGI R180 or the wests system that I"ve used. Haven't used RR yet.(The guy who imports it is very difficult to get hold of).

Repaired a crease on an epoxy PU board I built, with UV hi-lite poly and after a few weeks in the sun and surf etc. the difference is very notable. the repair is still a nice bright white colour while the rest of the board is yellowing.

Apparently FGI have a new resin that is supposed to be very bright and stay that way, and Lenny from shapers is talking about some new stuff they have in the pipelines with some resin manufacturer. Remains to be seen as to the claims of the epoxy manufacturers.


Hi Daren,

I’ve tried both RR and Kinetix, they both seemed very similar in all ways to me. So I think you’ll like it when you get a hold of it.

I have had experience with:

1. Resin Research (normal) - yellows on whole board very quickly. used on clark foam polyurethane blanks caused major shrinking after 6 months. on eps works great but yellows quite drastically the most quickly. having a layer of polyester (PE) resin over it seems to help some. a 'speed spray' doesnt help at all.

2. Surf Source - yellows around areas with a lot of resin - fin boxes, laps, etc but not nearly as drastic or as quickly as the normal Resin Research.

3. Resin Research CE - I have only used this on one of the molded eps blanks (US superfused) and it came out BRIGHT white and after 6 months still looks brand new. Very impressive combination of materials. I am interested to try it on some billet foam to see if it stays super clear as it has done with the molded eps blank.  Still am weary to try it on a urethane blank as RR originally claimed that Epoxy over urethane is superior to PE over urethane and there was no reason to use PE anymore.  Seemed good glassed a lot of boards with it  but 6 months to a year later ALL boards turned to crap - now I take the claims of the latest and greatest with a grain of salt. 

4. Greenroom - this resin seems to come out cloudy on a brand new board but after 6 months has not seemed to yellow a measureable amount. 

5. Resin Research Quick Quick - I have only used it for some hotcoats a couple weeks ago so I have no idea how the yellowing will be.

6. Fiberglass Hawaii - seemed same as Surf Source.

As well as learning about the yellowing of the different resins, I would love to hear the results of the different epoxy resins over a urethane core after 6 months to a year.  As I said before, normal Resin Research on Clark seemed good at first but turned really ugly after some time.  Does CE really solve the problem? Anyone out there with a CE covered urethane core with some time in the sun on it? What about other brand epoxies or foams  - similar instances or is the problem limited to normal Resin Research or the combination of Clark/RR? (I quit using epoxy over urethane after that first experience - but would be very open to trying it again if 3rd party users are having sucess over time)

Resin Research or Kinetix on Bennetts has been no problem for me. PU blanks glassed with epoxy last longer and flex better too I feel. It’s been so long since I glassed a PU blank in polyester though I can’t really remember how quick it yellowed, but I could swear it was quicker than RR or Kinetix. Next time I glass a PU board with RR I will look at spraying the blank white first just to see if I notice any difference in yellowing.

Interesting - sounds like my problem may have been isolated to the specific foam brand/epoxy formulation.  Would love to hear from more out there!

I had the same problem with another blank manufacturer. Used RR
again not so long ago on a blank from the same manufacturer and now no
problems. Same resin, same foam, same manufacturer but the problem is now

RR 2000 was never for urethane so it doesn’t have any UV block.  The foam yellows very quickly.  CE and KK both have UV absorber so they can be used on either urethane or EPS no problem.  We’ve done tests against every brand and in our tests CE and KK were the winners.  3000 hours in AZ sun with just some yellowing. That’s equivalent to 3 hours of surfing a day for three years.   All in all our resins have gotten better in the last couple years.  CE and KK have definitely been steps forward.

Hi Greg,

will you be phasing out your RR 2000 in favour of CE and Kwik Kick now? Or should I say is there much point in using 2000 over CE or Kwik Kick?


Hi Greg,

will you be phasing out your RR 2000 in favour of CE and Kwik Kick now? Or should I say is there much point in using 2000 over CE or Kwik Kick?


I make the phone call to my resin guy...."Dude ,I need some resin!" .....

It's all the same price.

... Hmmmmmmmm ...Give me the CE and the KK.

Soooo.... if you want to dump some of that "old" stuff" maybe we can work a deal......I like discounts......Ha Ha......

RR 2000 was never for urethane ...

Well if you look in the archives here on Swaylocks around 2004-2005, there was a guy asking everyone to try his epoxy over clark foam (urethane) - claiming it would net a better product - why would he do that if he knew his resin wasnt formulated for urethane? 

We sell lots of 2000 and it’s been improved dramatically. It also is much broader in application … beyond just boards. I personally like KK but that’s personal preference.  I like that we have three nice choices.

We had never seen that shrinking problem in Clark blanks when I suggested that.  Wasn’t until very lightweight foam became more popular … superlight and ultralight.  Never saw a blue do it … ever.  And we did hundreds. We then began to assess why.  We made some progress and then … poof … Clark is gone and replacing them is a myriad of terrible urethane that was generally bad no matter what resin was on them.  We then introduced CE in late 07 and the KK in 09, both making PU/epoxy a good option.  We’re also down to the companies who make good PU foam now and we’re seeing great results because of that. Being in the surfboard biz is constant change … a moving target.  We all do our best to keep up.

greg this got me wondering and im not at my shop to check but im buying my RR epoxy from seabase in the uk and using it on pu usblanks red, could you tell me if its the 2000, ce or kk im getting off them? as they dont advertise a choice im guessing im getting the 2000 of them, if so how do i go about getting the other versions?

im starting to step up production now and move away from doing mates only boards and i really need to speed things up a bit, i like getting a chemical bond with epoxy as its saves a shedload of sanding but weekend before last i glassed 4 boards lams and hotcoats both sides but it was a 15hr day!! and i cant realistically keep that up. i had started to think about having to go down the route of poly again ( price being a factor too) but i really dont want to, a for my health and b because it seems to yeild a much better board for my customer. being new to this shaping thing (board number 19 starts tmw) and competing against known brands/cheap chinese boards (and also economy at present) means i need to start reeling in the time im spending on each board.

id really like to be able to get this kk stuff here in the uk and ill hassle seabase about it but is there anyway you can force the issue from your end too?


oh uand going back to the thread, ive tried rr and surfsource and rr wins hands down. last 2 batches of surfsource i had had to be sent back as the hardener gelled up big time in its own container and nothing would bring it back to life, further reading suggested they do 2 versions, one of which wont solidify if it gets too cold but after being left with a few litres of f*%ked epoxy im never going back there. also its not as nice to sand as rr and just doesnt 'feel' as nice. oh and i had issues with using polyester pigments with surfsource whereas 'touch wood' rr isnt giving me the same issues.





Least yellowing epoxy?

That's easy - Coil.

How 'bout least least yellowing real surfboard, period.

Done with RR.

well now you have seen a clark blue glassed with RR with significant shrinkage. i have seen about 50 of them (greens also!) These boards seemed great at first but showed their true colors after some time (6 months to a year - this board is obviously much older at this point). You can see the fin boxes and stringer protruding up as well as the lap lines and foam pour lines. The logos are all sucken in.  This is not an acceptable combination of materials in my opinion.  I hope the new foam and the blue resin does in fact work better - will be interesting to see after some time has passed.....

on a side note - i still use RR on eps and think it is a great product. I was skeptical of the CE but so far on the eps it does seem to be a superior resin.  Cant wait to see some result with it on urethane after some serious surf time.  Also - I am so stoked on all the insight Loehr imparts on this website. Thank you. 

I am just showing some real results to compare against the claims. And would love others feedback on epoxy over urethane with different brand foam and resin.


My problem was exactly the same. Latest blank from the same manufacturer is fine however. Did you also say you used poly with the same batch of blanks and no problems?

I imagine that the color brightness has do to with the type of fibers you use in the coil construction? They appear to have some sort of color white fabric in them? Also have heard claims that they are glassed over with suncure PE - dont know if this is true or not but that could help also as PE resin seems to be much better with UV protection.  Coming close or way off?  C'mon Mike lets talk tech - you like to pimp the superiority of the coil (I am not disputing) but are notoriously shy when it comes to talking about why.  So why are the coils the 'least yellowing real surfboards, period'?  I know it is not the RR - it yellows quickly and everyone who has used it knows that.

Excuse the crapiness of the last two images. Shrinkage occurred in very similar places to yours? Either way, board is still holding together. Although it has yellowed going from memory it certainly hasn’t yellowed as much as poly would for me over the same period of time.

yeah same blanks glassed with PE had no problems.

If you get that kind of shrinkage, that is not an acceptable mix of materials.  How long have you had the new batch of blanks in the water?  Enough time for the same problem to manifest itself?  What is the foam brand?