Helping epoxy to set

[+wenestvedt]

I need help forcing some two-part epoxy to set. Please help me, Cachers!

 

I am making some Giant Nano containers, from the size of a few stacked quarters up to something the size of a softball. Some of them are large enough to attach magnets to using screws (as they are still bonded to steel plates from the hard drives in which they were originally mounted), and these are fine.

 

However, others have shallow recesses in their base into which I put a blob of two-party epoxy, on which I floated a flat magnet. [Thanks again, hard drives!] Three days later, the epoxy is still tacky in these, though it dried thoroughly where I used it to glue some glow-in-the-dark Pony beads to magnets (which I got from Sonicare toothbrush heads; I love me some free magnets!).

 

Is there any way to accelerate the thicker blobs of epoxy to finish drying? Can I safely ignore its stickiness and place them outside -- or will they fall apart if I do so?

 

Thanks for any suggestions!

 

- Will

[+kunarion]

Is there any way to accelerate the thicker blobs of epoxy to finish drying? Can I safely ignore its stickiness and place them outside -- or will they fall apart if I do so?

Heat it, if you're gluing items that won't be damaged by heat. The last time I had some finicky epoxy, I placed the bison tube above a night light. It cured in a few hours. When heated, some epoxies can get more fluid at first, may not be a big deal in your tackiness situation.

 

You definitely should be sure it's cured before placing.

Edited June 6, 2010 by kunarion

[+ihorn]

Also it could be that the mixture of the epoxy was off, and it wont ever fully cure. If that is the case then you would need to remix a new batch, and use it on the project. If you do option 2 then make sure to remove all the old epoxy.

[+bittsen]

You could try adding some Methyl Ethyl Ketone to the surface to help it cure.

 

 

A caveat... It's been demonstrated that magnets don't secure well to epoxy over time.

[oakenwood]

In my experience, when epoxy doesn't cure well, it's not mixed enough. Give it a thorough mixing; it won't set that fast.

[+mchaos]

Is there any way to accelerate the thicker blobs of epoxy to finish drying? Can I safely ignore its stickiness and place them outside -- or will they fall apart if I do so?

Heat it, if you're gluing items that won't be damaged by heat. The last time I had some finicky epoxy, I placed the bison tube above a night light. It cured in a few hours. When heated, some epoxies can get more fluid at first, may not be a big deal in your tackiness situation.

 

You definitely should be sure it's cured before placing.

 

Defiantly heat. A good amount of heat can compensate for lack of hardener or too much. It will excite the chain reaction. But it will get real hot once it goes.

 

I do fiber glassing from time to time. winter before last, I had to get a project for some one done, and it was really cold. I had to keep a big halogen shop light on it. Once the reaction gets going, it usually hardens quick.

[+Dread_Pirate_Bruce]

Why does MEK help epoxy cure? I would expect just the opposite.

[+bittsen]

Why does MEK help epoxy cure? I would expect just the opposite.

 

It's just a theory.

MEK is what makes fiberglass resin set (if I remember correctly from my plastics class a couple decades ago)

[+EScout]

If it has not cured in 3 days, I would scrape and start over with another epoxy. I assume that you mixed the two parts well. So, you have a poor quality epoxy or it is old. I recommend JB Weld Kwik. It is fast setting and you will see a nice shiny hard surface very soon. The package says it bonds in 4 minutes and cures in 4 hours.

[4wheelin_fool]

I would use JB Weld, or even JB quick weld. I've had mostly good results with that.

[+wenestvedt]

Hmmm, heat didn't help. It *is* pretty old, so that must be it. I'll scrape it off tonight and try again.

 

Thanks everyone!

 

- Will