CA burns

[karatekicker271]

Ok, following Neils "Sparkler Burns" maybe this one isn't so common. I was super glueing a shock cord mount into a rocket and my fingers got stuck to the mount. I have gotten super glue on my figers before, even gotten my whole hand stuck together, but the shockcord mount was stuck on there, and it started to burn really bad, like i was sticking my hand over a lighter. I pulled it off, and now my finger is red and blistering. Anyone know why this might happen?

 

[SecretSquirrel]

The chemical reaction of the curing process produces heat

 

[AlexM]

Did you use accelerator? Or could there have been something in the shock cord that reacts?

 

[karatekicker271]

It was the same brand that I have used since day 1, nothing different and I have glued shock cords in there before... dunno

 

[Donaldsrockets]

CA will also burn carpeting down to the pad if you accidently spill some on it. It also makes a sizzling noise in the process.

I've accidently done it before.

 

[Ryan S.]

you dont have a problem if you use it in small quantities, however if you use alot on a paper product, it will get very hot...in some cases start smoldering. The fumes hurt alot when they get in your eyes and lungs

 

[Ray Dunakin]

CA produces heat as it cures, and the faster it cures the hotter it gets. I once wiped off some thin CA that dribbled onto the outside of a tube, and the CA soaked through the paper towel and stuck it to my finger while burning me hot enough to form a large blister! It sucks to have something that hot stuck to you so you can't get it off quickly.

Which reminds me of a funny true story:

Many years ago, my brother Mark wanted to make a plaster mold of his hand. So he mixed up a bucket full of hydrocal (high grade plaster) and stuck his hand in it. Trouble is, he forgot two things --- One, plaster gets hot when it sets especially if you mix it thick like he did; and two, your hand is bigger than your wrist.

So next thing we know, Mark's running around with this bucket full of plaster stuck to the end of his arm, hollering and pounding the bucket against the ground trying to break it loose.

 

[kelltym88]

I'm not exactly sure what CA is, I'm assuming it's Super Glue? I don't know if this is the same thing, but I was using 12 minute epoxy on my PML Matrix today gluing the centering ring to the bulkhead. After a couplr of minutes I picked it up to move it and it was pretty hot. I figured there was something in there tubes that caused the chemicals to react that way. That was the first time I ever noticed that.

 

[Ray Dunakin]

Originally posted by kelltym88
I'm not exactly sure what CA is, I'm assuming it's Super Glue? I don't know if this is the same thing, but I was using 12 minute epoxy on my PML Matrix today gluing the centering ring to the bulkhead. After a couplr of minutes I picked it up to move it and it was pretty hot. I figured there was something in there tubes that caused the chemicals to react that way. That was the first time I ever noticed that.

CA is Cyanoacrylate Adhesive, aka "super glue". The stuff they sell in tiny little tubes is usually cheap junk. Hobby shops have larger bottles of better quality CA, in thin (aka "fast") or thick (aka "slow") formulas.

Epoxy also generates heat as it cures but usually not so noticeable since it cures much more slowly. Same with polyester resin.

 

[karatekicker271]

What happened to marks hand?

 

[BlueNinja]

Originally posted by kelltym88
I'm not exactly sure what CA is, I'm assuming it's Super Glue? I don't know if this is the same thing, but I was using 12 minute epoxy on my PML Matrix today gluing the centering ring to the bulkhead. After a couplr of minutes I picked it up to move it and it was pretty hot. I figured there was something in there tubes that caused the chemicals to react that way. That was the first time I ever noticed that.

Yeah, epoxy will make a exothermic reaction when it cures... Some will "flash cure" and vaporize and pretty much turn to liquid. I think Us composites sells powdered aluminum to mix into the epoxy to dissipate heat. You can keep it from flash curing by:

spreading it out in a large pan

not heating it

Blue

 

[Ray Dunakin]

Originally posted by karatekicker271
What happened to marks hand?

Nothing serious, fortunately. It was pretty red but didn't blister or anything. The plaster broke off after several minutes of pounding it against the driveway.