CA Glue ?

[Tim Boger]

Hey Guys ....

1) what would be an approximate shelf life for Super Glue?
2) what is the active ingredient in the "accelerator"?

Thanks,
Tim

[Scott Hackler]

Shelf life is quite a long time, in my experience. I buy StarBond bottles and leave them in the shop fridge until I need another bottle (don't know 100% if that extends it but someone said that once so I do it). I also don't usually cap the bottles in the shop (loose the caps) and it does NOT set up in the bottle.

Not for sure whats in the accelerator but water cures CA glue and so I would bet the primary ingredient is water.

[David Gilbert]

The active ingredient of the accelerator is usually some kind of tertiary amine. The amine attacks the double bond in the cyanoacrylate molecule that then initiates the polymerization of the surrounding molecules. Water will also initiate the polymerization but not as effectively as the amines and is why we use CA glues to glue up wood since wood always has some water in it. Almost any amine or base will act to initiate these reactions but because many of the amines have unpleasant smells the ones they use have higher molecular weights so they don't stink as much. My experience is that most of the accelerators use either methanol or ethanol as a solvent.

I don't know how long CA glue is good for but we used some for a demonstration that was at least a year old (maybe two) and it was very brittle and the turnings kept flying off the lathe. Fresh CA didn't have the same problem. I also know that refrigerating a bottle will preserve it longer than if it is sitting on the bench.

Can you guess who was trained as a chemist?

Cheers,
David

[Dan Hintz]

Dave got it with the base part for the accelerator... I mix up a small bottle of ammonia and water. My experience has shown medium CA (my biggest user) lasts for 2-3 years in a cool, controlled environment (my dehumidified basement). The few bottles of medium I have are starting to get a little too thick for good use, so I'll be replacing them soon. The thin CA looks like it will last out the decade without issue, likely longer.

[Tim Boger]

Dave got it with the base part for the accelerator... I mix up a small bottle of acetone and water. My experience has shown medium CA (my biggest user) lasts for 2-3 years in a cool, controlled environment (my dehumidified basement). The few bottles of medium I have are starting to get a little too thick for good use, so I'll be replacing them soon. The thin CA looks like it will last out the decade without issue, likely longer.

Thanks guys for the feedback, my CA glue which is certainly over a year old had me wondering .... I also ran out of the accelerator and thought Acetone alone would cause the material to set immediately, it didn't seem to work like I had hoped.

Dan, I'll add some water to the Acetone, what ratio is suggested ... 50 /50?

Thanks,
Tim

[Dale Gillaspy]

I don't understand the acetone part, because I keep a small squeeze bottle of acetone handy as a solvent when I stick my fingers together….I mean, if I ever were do do such a silly thing. Seems to me it wouldn't work both ways, but I'm not a chemist…what do I know. I use a small spray bottle of water as an accelerator if I need it, and it works great. My medium CA is well over a year and going strong. My thin seems to hold well, but getting a little thick after a year, so I think it is about done.

[Jim Meyer]

I ran out of accelerator, And used a spray disinfectant that my wife used in the bathroom. Worked for me. Jim

[Dan Hintz]

You're right Dale, it wasn't acetone... I think I grabbed the bottle of ammonia. Throwing some baking soda in water will give you a lightly basic solution, too.

[robert baccus]

I read a bit of moisture was necessary to set up CA but the set up is actually due to an absence of oxygen. Try 2 dry fingers sometime. Hot weather plays havoc with thicker CA's performance for sure. I'm chicken--I do a 2 stick test frequently and before big heavy blocks get mounted.

[John Coloccia]

Acetone is a solvent for CA. I definitely wouldn't use that for accelerator Just buy a small bottle of accelerator. It works much better than the homemade solutions.

re: shelf life
Rule of thumb since the beginning of time is 1 year. You might get longer....you might not. Your glue may already be 6 months old by the time you get it. Unless you're using the stuff in industrial quantities, the best course of action IMHO is buy the smallest bottle you can that will get you through the next 6 months, and just toss them after a year.

[Michael Dromey]

On the shelf life. I have three bottles I have bee using since March 08. I marked the date when opened. I just used some the other day. They seem to be just fine so far. And yes I have kept them in the fridge all this time except to used them.

[Alan Trout]

Actually,

Acetone is common to use as the carrier of the amine. Acetone is used as it evaporates quickly and deposits the amine. This is usually considered the more aggressive type of accelerator which is what I prefer. However if you use to much it can dissolve the CA as well. I am a dealer for one of the glue brands and Acetone is the carrier in their standard accelerator. Also Starbond's standard accelerator uses acetone as its carrier.

Alan

[John Coloccia]

Hi, Alan. It was in response to the idea someone mentioned of using acetone alone as an accelerator.

[David Gilbert]

I have heard of folks who believe that oxygen is the initiator for CA glue to set up. If that were the case then we would all have bottles that were completely set up since there is oxygen everywhere around us. CA needs another chemical (amine, base, water, etc.) to start the polymerization. Oxygen can't do it. There are even some who suggest leaving the bottle open and that way the caps don't get plugged. Clearly the CA is exposed to oxygen all the time and doesn't react with it.

Acetone is good solvent for CA glue whether in liquid or polymerized state. I will use it to dissolve the cured polymer that encrusts all of our caps as well as the CA that reacts with our fingers.

Cheers,
David

[Bill Boehme]

I have kept CA for years in the garage fridge. The accelerator ingredients vary, but some of the most common usually found in some combination include acetone, heptane, N,, N Dimethyl-P Toluidine, and butyl acerare-1. Common debonders include nitro methane and methylene chloride.