Epoxy adhesive not curing - Bummer?

[Bucko6]

Building a woodie and used West System Six10 epoxy to glue a boat load of wood trim on the sides. The Six10 is a new product in a caulk tube and pre mixes the two parts as the epoxy comes out of the tip. Says it cures in 45 minutes full hard in 4-5 hours @ 75f. I started work about 6 hours ago and the temperature was only 55f but no mention about a minimum working temperature. I figured it should be hardening by now but it is just gooey. How bad is the news?

[doug hodder]

Epoxies are temp. sensitive. In cool temps, the cure time is much longer and chances are, the strength won't be as high as if it were done in warmer temps. I'm not familiar with the Six 10 product, but have used similar products with the mixing chamber type tip on them. All I use is West, but then I apply in warmer temps and haven't ever had an issue with their products, not the Six 10 however. I'd say...if you can get it warm...do it...see what happens. Call their 800# and talk to the tech guys on Monday. Doug

[Bucko6]

Thanks for the reply. I probably will call on Monday. Right now, it looks like it is curing. Some areas are still sticky but after sitting in the cold garage overnight, I have some hope.

[Artificer]

If you have the ratio correct, its probably already cured this morning. If I had to guess at the set time at the lower temperature, I would say the working time would tripple at 55degF as opposed to 75degF.

I picked up the "slow" epoxy from US composites to do the top of my latest trailer. At 65-70deg it was definitely slower than spec'ed. I put a heat lamp on one section, and it cured within a few hours. It probably didn't fully cure until it hit the heat in Texas this week.

Either just wait, and let it cure, or find some way to add some heat. Keep the surface under 140degF, however.

Michael

[Dale M.]

If its in garage and if you have a "space heater" up the temperature of garage for the day....



Dale

[Larry C]

If its in garage and if you have a "space heater" up the temperature of garage for the day....



Dale

I agree temperature is the issue, but I would caution using the type of heater in Dale's picture. I used to service these heaters. They burn kerosene, and the nose cone in the front acts as an afterburner when it's bright red.

When these heaters cycle on and off, if attached to a thermostat, they tend to emit some unburned fuel into the air at start up until the nose cone turns bright red.

After several cycles the atmosphere becomes saturated with an unburned kerosene mist. If the heater runs continuous this is less an issue, but most people use a thermostat or manually disconnect to maintain temperature or it will get way too warm.
The on/off cycle causes the greatest mist.

The fuel mist can have a detrimental affect on uncured epoxy, especially adhesion.

I would suggest a different heat source for curing epoxy.

Larry C

[Wanna Be]

These type of heaters WILL work with the thermostat exposed to a lower temp than the inside where the glue is drying.

I have used this type in the curing of epoxy paint with no problems.

Keep the intake exposed to the fresh air, and if to hot open more doors
to regulate the temps.

Yes, the mist on start-up will interfear with the finished product. The key is to eliminate the cycling of the heater.

Just my $0.02 worth of experience.

Stay safe, and have fun !!!!

Wanna Be

[Bucko6]

Looks like all I needed was more time for the epoxy to cure at lower temps. Thanks all for your advice.

[Deryk the Pirate]

Yeah Ive done a decent amount of fiberglassing and temp is important for cureing. As long as its mixed corectly in a cooler temp it will take longer to set. I remember once it was a particularly hot day and I mixed a batch, walked a few steps to my boat and tried to give it 1 last stir with the brush and boom it was solid lol. Dont mix larger batches when its hot out lol.

[doug hodder]

I've found that both the kerosene wick type heaters and the forced air/kero fueled ones tend to put out a lot of moisture as well. My wick type rusted the top on the table saw. That's bad news on epoxies, especially if you are planning on a clear finish on a woody. I think you'd do better with a dry, like electric or vented heat source.

I'm fortunate in that I've got a wood stove and in the winter can work in shorts and T in the garage when I do epoxy work. For future work, maybe you could put an electric heater IN the tear and heat it from the inside out. That would at least stop it from maybe having a cold side. Doug

[Dale M.]

They also make propane versions of these "space heaters".... Picture in above post was for example of a "space heater" and by no means recommending any particular type....My only real suggestion is do something to produce heat to accelerate the epoxy cure so one can get on with the build...





Dale