Epoxy not curing

G’day All,

I have a done a thorough search but have been unable to find a distinct answer to my question. I have just laminated the bottom of a home depot EPS balnk with two sheets of 6 ounce cloth and MIAPOXY resin and hardener. The mix is supposed to be 4 to 1. My problem is that I was a bit eager and the temperature was not warm enough when glassing. It has been about two weeks now and the resin has still not cured. I have moved the boar to a warmer place and am hoping that it may somehow miraculously cure… Am I dreaming or is there some hope? Are there any other suggestions out there that may rectify my juvenile mistake. It was my first go at it, and well we learn from our mistakes!

Any advice would be greatly appreciated.

Cheers

Hey Browntown

Sorry to hear about your problems. I have just finished my first board and had a similar issue. Fortunately for me it was just a resin coat that did not cure properly and I was able to scrape the gummy resin off. I have loads of experience with epoxies (not surfing related!) and should have known better, however i’m impatient and went for it hoping it’d be ok…

In answer to your question, there is no quick fix, epoxies need to be cured at or above the recomended minimum working temperature. (usually somewhere around the 20 C mark) if after 2 weeks its not cured, you are knackered! People will no doubt recomend heat as a possible solution, it may help, but it will not work fully.

How bad is it? Is the laminate rubbery or still sticky?

For next time here are some good pointers

1.If it is cold when you are laminating, warm the resin before and during mixing, you want to get it well above the working temp, this will kick off the cure but will shorten your working time and lower the viscosity of the resin.

  1. Make a curing oven! I used the cardboard box my blank came in, open it up and stick some ends on it, then after laminating put the box/oven over your board and blow hot air in with a fan heater. If you have warmed the resin before hand, an hour or two will be enough to get the bulk of the cure done. Make sure you have the board sitting on a small box to raise it to the top of the oven, dont blow the hot air directly on the board. I believe heating the blank during curing is frowned upon as the blank can ‘blow’ as the gasses expand, i’ve been woring with foams and composite laminates for years and never had an issue…

  2. One little thing to remember is that epoxies will sometimes feel sticky after curing, this is the amine blush, a waxy film that is a by-product of curing, it can be washed off with warm water, you need to do this before sanding/recoating.

Hope this helps for next time!

A

I feel your pain. Just recently I had to peel off some beautiful veneer when some epoxy did not cure. At least you didn’t spend $100 for the blank! I was able to save my blank…because I had spackled and the resin didn’t penetrate very far. But I lost a real nice piece of veneer and some glass and epoxy. try to do what you can but sometimes we just f…k up. Oh well…

If it’s any consolation I think I just f…ked up my board a second time! doing a poly gloss over an epoxy board. My error was thinking epoxy when using poly. I poured out the poly gloss and it looked like too much. I’d been using less for my hotcoats with epoxy with left over. So I poured some back in the can. Stupid! I poured the resin out on the board and started spreading it out and realised I didn’t have enough. If it was epoxy I could have calmly mixed some more. Not so with poly right? I tried to brush it over dry areas to no avail. All I did was make the gloss coat bumpy. I’m thinking I’m going to have to sand off the gloss…which if I recall is not the most sandable resin. Another day of labor! I’m so over poly. Never again. Live and learn.

I havent used that epoxy but as reassurance i often put left over resin in the freezer to pull out and reuse later. If I forget and leave them i have found that they eventually go hard anyway. So don’t panic yet. If you heat it make sure it is with the board well suported as I suspect that it may twist or flop or generally change shape a little.

Mark

heres a way to do poly gloss over epoxy

http://www.youtube.com/watch?v=LvvWVLlkNAk&feature=related

the board is finished to 100 grit

some epoxys do not take polyester top coats very well

epoxys dont cure when the are under hardened or over hardend to much

HI Paul,

Yeah I watched that video. You make it look easy. I thought it’d go like that for me too. I just didn’t mix enough resin, there were dry spots and I tried to brush resin over to them and just mucked everything up. Total disaster. I did my deck with epoxy and additive F. Tommorow I’ll flip the f…cker and sand off the poly and just do epoxy. Live and learn. Oh, and since I make boards in the bedroom of our condo the smell of poly was just too much.

Jeff

I’ve had similar problems with cold epoxies. In my case the solution was warming the resin up before mixing. It turns out that the epoxy resin is so thick when cold that I was not adequately mixing.

My solution? A 5 gallon bucket half filled with hot tap water. Drop epoxy resin in 10 minutes before mixing. Then, no problem mixing or curing (a tip I got from a 20 year epoxy lam pro).

HTH.

PS. I am pretty sure you will need to scrape the gooey stuff off the lam and start over.

Thanks all for the responses. Next time I will try to acknowledge the phrase ’ patience is a virtue '. I would have liked to use the Resin Research, but as I am living in Quebec the only resin that I had available was the Miapoxy. There is a local shaper here and that is what he had recommended.

We learn from our mistakes and I’ll be sure to make a mends for that on my next attempt.

Thanks again and all the best…

Hey Browntown,

I’m with Blakestah, Definitely warm the resin first before mixing. It reduces viscosity and gives a little heat to promote curing.

I use Resin Research just about every day in some way or another. My shop temp is around 55-60 degrees F [12-15 C] in the winter and I’ve never had an issue with epoxy curing.

3 tips to ensure full epoxy cure every time:

  1. Measure ratio very accurately

  2. Pour Resin component into mixing bucket / heat in microwave 3 seconds per ounce (never heat Hardener) / then add appropriate amount of Hardener.

  3. Mix Thoroughly for at least 2 minutes. Slow and steady, scrape sides and corners of bucket with mixing stick.

~Brian

www.greenlightsurfsupply.com

along with what brian said. ive been using the RR Xcelerator with all of my laminations as of late. i usually pour alittle bit in. i use it as a back up just incase my pumping is alittle screwy. i have yet to have anything not cure fully.tho when i didnt use it and was shaping in the coldest room in the house. probably 40-60 degrees it would take 2 or more days for the resin to fully cure.

which reminds me i need to order more pumps. damn resin one doesnt fully pump.