Just laminated the bottom.... epoxy is yellow.... normal? *PICS added*

i just laminated the bottom of my board with epoxy i got from a distributor in california. its from Aeromarine, nonblush epoxy and it seems to work fine, but the only concern i have is that its got a yellowish tint to it. much like the west system epoxy does. so do all epoxy’s come out in a yellowish color? or am i just SOL and better off using another type of resin? is it possible that it will cure clear?

actually, come to think of it, my friend glassed his board with an epoxy called MAS epoxy, and his was clear…

can i paint over it later after sanding to give it a white finish? although its not really that big of a deal. its my first board, making mistakes left and right…

any suggestions?

generally slower hardeners are clearer

basically the average epoxy hardener has a limited shelf life

and goes pretty yellow after a period of time

manufactures have different barrels of different ages and thus different degrees of yellow

for an outer lam you really need a surfboard specific epoxy that is less inclined to yellow

or do what i do and use a post cure type as they tend to be very clear

but are a bit of a hassle cuz you need to bake the lam

How yellow? Got any pics

I use West System 105 resin with 206 hardener (slow) and it cures clear.

Does tend to yellow over time quicker than Polyester resin though.

-Cam

Howzit silly, Ever notice how the hardener turns brown after being exposed to air for a while,especially around the lid. That is just another reason I don’t like using it since the brown changes the color of the epoxy.Aloha,Kokua

I’ve only used RR epoxy, but both the epoxy and hardener are clear at all stages. Ben uses a epoxy from tap plastics that is sort of yellow, but it looks really good over the balsa.

yes kokua i have the same deal

what i do is buy the epoxy by the 20 litre

and hardener by the 1 litre

that way i have new hardener every few boards

it still sometimes has a yellow tint and looks crap on a white board

im trying an slow cure hardener at the moment

it is crystal clear and the hardener doesnt yellow

but i have to bake the lam for 6 hours at 50 to 60 degrees celsious

(Black bag in the sun)

it is however and incredibly tough and thermaly stable result

makes it worth it

Silly, do you know if slower hardeners in general are stronger/more thermally stable?

JSS

here are some pics of what im talking about. i actually dont really mind the color too much… oh yeah im also color blind… so maybe its not really yellowish green… haha:

thermally stable…not what’s causing the issue.

issue is oxidation; n-oxides form upon exposure to air.

and it happens to everybody’s hardener; even resin research, just that some are faster than others.

also, some hardeners are yellow without any oxidation; usually these contain anilines or guanidines as the crosslinking agents rather than just amines.

earlier expoxies that yellowed on prolonger exposure to sunlight etc.; usually oxidation issues. modern day? with a well formulated system? shouldn’t be an issue any more.

So i have some  old RR epoxy and was getting ready to glass some boards tonight. But last night i noticed the hardener is a solid yellow color. I put in the fin boxes and stuff kicked fine but i am guessing that when i lam i will get a yellowish board. Does that about sum it uP?

I had a 3 gallon kit that the hardener was yellow from Aeromarine I sent a pic of it to John Greer the owner and he sent me a new gallon of hardener that was crystal clear, it was the only time I had that happen. I've been using Aeromarine epoxy for years and that was the only time that happened. Look at your containers of epoxy and hardener, I bet the hardener is yellow. You got the 300/21 system I believe. Call him and he will send you new stuff. I just got another batch from him yesterday and it's crystal clear.

Tom

So the resin is drying clear and staying clear?  was interested in the stuff a while back but it mentioned somewhere on the site about yellowing.  maybe they improved it

If you’re building epoxy boards using resin that may be “less than clear” …  Try  mixing the epoxy with yellow, green, red, orange tints…Any color that compliments yellow… The color of the resin has nothing to do with it’s strength…

Any further “yellowing” can only improve the base color…

 Keep the board in a bag…

Ive used aeromarine on multiple boards and they all came out clear.... Guessing with a lot of sun exposure over time they will yellow but from what Ive read thats pretty normal.