Epoxy cure time

[Aaron Craven]

I'm using two-part 5-minute epoxy to fill a small void. I know it sets in 5 minutes (duh), but how long do I need to wait until it's cured enough to continue work on my bowl?

[Brice Rogers]

I typically wait over night. If I'm in a hurry, and its a thin void (more like a crack), I'd probably fill the void with sawdust and soak it with CA (superglue). But even then I'd leave if for a few hours to cure, especially if it was deep. I'd hate to spin it up and have the piece spitting superglue at me.

[Aaron Craven]

I typically wait over night. If I'm in a hurry, and its a thin void (more like a crack), I'd probably fill the void with sawdust and soak it with CA (superglue). But even then I'd leave if for a few hours to cure, especially if it was deep. I'd hate to spin it up and have the piece spitting superglue at me.

No kidding... that stuff is wicked. I was using it for some small cracks on the same piece. Tried to be very careful, but still got fumes in my eyes... ouch.

[Reed Gray]

Ventilation when using CA glue is a good idea. Been there, done that, more than once....

robo hippy

[Edward Weingarden]

I typically wait over night. If I'm in a hurry, and its a thin void (more like a crack), I'd probably fill the void with sawdust and soak it with CA (superglue). But even then I'd leave if for a few hours to cure, especially if it was deep. I'd hate to spin it up and have the piece spitting superglue at me.

Give a spritz of accelerator and it will cure instantaneously.

[Brian Brown]

Give a spritz of accelerator and it will cure instantaneously.

The instant cure is only on the surface. I had a piece that I "accelerated", and left for about 5 minutes. When I turned off the hard shell and props, the CA inside came out and spattered my face shield.

[Aaron Craven]

I've been using HF superglue... Haven't had any trouble waiting for it to cure like that, but I don't use any accelerator. But then, for deep voids or cracks, I generally don't go with CA. I took a chance with the epoxy after about two hours and finished up the bowl. Worked great! This spalted cherry was difficult to work with (It took a fair amount of "80-grit scraper" to get a smooth surface on the inside), but it was such beautiful wood!

323616

[Keith Westfall]

I'm using two-part 5-minute epoxy to fill a small void.

How did we go from 5 minute epoxy to CA glue so quick?

[robert baccus]

FYI- epoxy sands and cuts much better than CA. Also accelerator can turn CA white.

[Aaron Craven]

FYI- epoxy sands and cuts much better than CA. Also accelerator can turn CA white.

I generally only use CA for stabilizing punky wood or when filling very small cracks (with or without shavings)... I've only used epoxy twice, but with pretty good results. I do wish it was slightly thinner liquid so it would flow into the piece a little better... I tend to get very small gaps in narrow areas sometimes. But then, that could be the epoxy I'm using (HF)... I buy it because it's cheap. I'm sure other formulations are probably better.

[Pat Scott]

Back to the original question - I'd wait overnight like Brice said. I use epoxy quite a bit, but for filling voids and larger cracks I usually use the slow set epoxy. The 5 minute epoxy starts setting up too soon before the epoxy has flowed down into the void/crack. Many times you'll start working on the piece again only to find there are air bubble pockets that need filled again. I rarely have that problem with slow setting epoxy, which I will let cure for several days before working.

[Prashun Patel]

if it makes a sound when I tap it with my fingernail I consider it ready to cut. I have now started dying epoxy. It makes it opaque which prevents bubbles from being visible as they are in clear.

[Aaron Craven]

...I usually use the slow set epoxy. The 5 minute epoxy starts setting up too soon before the epoxy has flowed down into the void/crack. Many times you'll start working on the piece again only to find there are air bubble pockets that need filled again. I rarely have that problem with slow setting epoxy, which I will let cure for several days before working.

This is something I need to look into. As I mentioned in another comment, I have had this exact problem. Though in my case, I've just left it instead of filling again. I've only used epoxy twice and the small pockets didn't detract much in these pieces.

[Ben Pierce]

I've pushed it enough times to have learned that the epoxy needs to cure "overnight", or 10 hours, or whatever. If it gums up when you sand, it'll likely pull some out of the void and mess up the job. Ditto previous comments about the quick-set stuff and air bubbles. I like to fill the void, do something else for a few minutes, and come back to it after the epoxy has had time to run down into the void. It also has to vent itself, i.e. it can't flow into the hole without a little bubble to displace the air that was in the hole, thus the darn air bubbles. Revisiting and pushing more still-liquid epoxy over the top takes care of it.

[bobby stout]

I build fishing rods and the epoxy I use is a 2 part which is applied while the rod is turning and it levels out. I use the same on the cracks that I fill you can use a little heat and the air bubbles will rise to the top. Not too much heat you do not want it to burn I use a hair dryer so for no air holes left in the epoxy

[Brad Barnhart]

I live out here in NW Kansas. We're doing good to get lumber at our local lumber yard, much less any necessities. Where can I find this CA or epoxy? I haven't done any bowl turning yet, but that's not to say I won't.

[Aaron Craven]

I live out here in NW Kansas. We're doing good to get lumber at our local lumber yard, much less any necessities. Where can I find this CA or epoxy? I haven't done any bowl turning yet, but that's not to say I won't.

CA is fancy-speak for superglue... I'm sure there are advantages of high-end stuff, but I just use the Harbor Freight cheap variety and it works fine (maybe even better than the Loctite brand I used first -- the HF brand seems a little thinner). Not sure why woodturners like to call it CA (cyanoacrylate) as opposed to "superglue", but it's the same stuff. Likewise, two-part epoxy comes in everything from high end to utility brands. Here again, I've just been using Harbor Freight tubes, and they seem to work nicely. There are two different styles though... there's one that dries to a gray color, which I've never used, and there's clear (which is probably what you'll want). It also comes with various initial set-up times (referred to as "pot life"). The 5-minute variety I'm using is pretty common.

For both, there are tons of videos and articles out there talking about how to use them to fill cracks and voids. The biggest difference is that CA won't "bridge" a wide gap like epoxy will, and while epoxy cures much more slowly, it's a little more pleasant to work with. CA dries quickly and generates a lot of heat and fumes... One thing to know -- never put it on cotton or natural fibers and always wear gloves when applying it. Kitchen type paper towels are not a good choice, for some reason (the glue reacts pretty vigorously and heats up quickly). The blue shop towels work fairly well, though. The fumes are rough too... they irritate the nose and will really sting if they get in your eyes. I've heard some nasty stories about CA getting on clothing and causing 2nd or 3rd degree burns while simultaneously gluing the clothing to the skin, so be really careful.

[Brad Barnhart]

Thank you for the input, Aaron. This is something i'll have to some looking into.

[Keith Westfall]

Hobby shops are often a good place to look as well.