Epoxy not hardening

[Old Salt]

I had some flexcoat around for a couple of years. I had crystals in the bottom, so I treated it like I do my boat building epoxy and soaked the container in hot water to disolve the crystals. I was careful about mixing, as I know from experience (probably 50 gallons of epoxy experience) that mixing is critical. End result is that my flexcoat high build is not hardening entirely. It is pretty hard but still a bit tacky to the touch. I took a hair drier to it to see if heat would kick it off...but not change. When I was working with the epoxy, it started it's chemical reaction in the antisipated time period and seemed to be doing what epoxy does. Any suggestions for curing my problem and for the future.

[OnTheSauk]

I'd be inclined to buy fresh, mix carefully and put on a second thin coat. Seems to be the one most common problem in rod building and as you say, usually not mixed exactly. Good luck.

[sothereiwas]

There are two different types of resin laminating and finish, Laminating resins will set up but stay tacky. They are designed for multiple coats the last sealing in the first and causing it to cure all the way. Finishing resins will cure completely but that dont adhere to the next layer as well.

Not sure if this relates to your problem but I had the same experience using laminating resin by accident building custom subwoofer enclosures. if this is your problem than a thin coat of finishing resin will seal in the laminating resin and they will both then completely cure.

Brad

[Grady252]

I am sure you have a lot of experience mixing epoxy, but in such small amounts it is critical. Very small margin of error. Just mix up another batch being very careful to fully mix it and then coat it again, the new stuff will make the old stuff go off, and in addition the new stuff will harden.

I have used very old flex coat, and as long as they are not mixed they have a long shelf life. I am very careful when I mix mine as well, but it happened to me once too.

I have seen this same question on the rodbuilding.org site and the answer is always the same.

Good luck!

[TheCamel]

I'd be inclined to buy fresh, mix carefully and put on a second thin coat. Seems to be the one most common problem in rod building and as you say, usually not mixed exactly. Good luck.
:agree:

You might buy Flex-Coat Lite for the second coat if you are concerned about too much build up.

[fishassassin]

A little tid-bit, I have had the same issue, A friend and I found by adding a few drops of accetone to the mix. It word hardend like concrete. I would consider stripping off the coat that wont harden and retry with a new mix.

Good luck :)

[Holley Rod Wrapper]

Make sure your room temp stays at 70 degrees for the total cure time, I have had the same issue in the past.
Both time it was 20 degrees out and the shop heater got unplugged by an energy paranoid other. I now use a propane catalytic heater, keeps it right around 75 overnight.

[CATCH AND EAT]

For most adhesives, paints and epoxies you must surface temps staying around 60 F. If you do not follow this the products will not kick effectively and will not dry correctly. And never use old products that have crystallized. The chemical compensation has been compromised and you should remove what you have done and start over. Better now than later and it will save a huge headache down the road.

Good luck and bummer this happened to you.

[chinookin]

according to flex coat, if you remix making sure amounts are correct, (and maybe getting fresh depending on how old) it will solve the problem. That comes right out of the manufactures paperwork. Good luck.