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.

[Paul Gilbert]

I often use Windex as a stop gap accelerator. It contains ammonia in a alcohol solvent. I assume that it also contains some water. That's all you need, the hydroxide radical and some water.

[robert baccus]

Dave, the lack of oxygen is the set up thing for CA. This is the reasoning for some guys to leave the tops open. The only condition that seems to degrade CA for me is high temperatures. Try two fingers tapped together very quickly with a small drop of thin CA.---with acetone handy of course.

[David Gilbert]

Dave, the lack of oxygen is the set up thing for CA.

Sorry Robert but the chemistry doesn't work this way. The presence of water in your fingers is what activates the CA. If you put a drop of CA on your finger it will harden even though there is oxygen around it. If I still had a lab to play (work) in it would be easy to show that CA will cure with or without oxygen. It's the water or base that causes CA glue to set up and oxygen has nothing to do with it.

Cheers,
David

[John Coloccia]

If it cured due to lack of oxygen, the glue would instantly harden from the bottom up and you'd end up with a large bottle of hard plastic with a thin film of liquid glue on top.

[robert baccus]

Sorry Dave But after some heavy research CA apparently does not set up in wet air but must be pressed tightly to expel air. Some how the water in this air condenses causeing it to catalyze. Hard to wrap my head around this but I know CA on a wood surface will not harden until it is pressed against another surface. Many truths are not readily apparent??? This was a really fun thread Tim. Did some testing using new sriring sticks. Dampened with a rag , glued and clamped 5 minutes--easily broken. The same with dry sticks ect. and the wood broke first. ????

[Tim Boger]

I'll tell you one thing Robert ... I have learned far more about CA glue than I would have imagined !

What an amazing resource this group is.

[John Coloccia]

If you leave a glob of ca in the open, it will skin over and eventually cure if it's not too thick. In other words, the part exposed to the most oxygen cures first. While lack of oxygen may be a helpful condition, reread my earlier post. Research manufacturer websites and they will tell you that generally moisture triggers cure.

[John Coloccia]

That last post was from my phone. I took a second when I got home and simply looked it up:

http://en.wikipedia.org/wiki/Cyanoacrylate

The word "oxygen" is not mentioned once, FWIW. I know there are websites that say you need to squeeze out the oxygen. I don't know where they got that from. I don't want to be argumentative, but I do want the correct information to be out there.

[robert baccus]

I read the same thing John and cannot explain this. But I never put anything on SMC unless I have done it many times. I actually went outside last night and repeated the above experiment twice????? I have also read the oxygen thing in the past but could not locate it last night. I found out one thing---never CA your self to anything you can't drag away.

[Dan Hintz]

Try two fingers tapped together very quickly with a small drop of thin CA.---with acetone handy of course.


Hard to wrap my head around this but I know CA on a wood surface will not harden until it is pressed against another surface.


I actually went outside last night and repeated the above experiment twice?????

Robert,

I think you're making conclusions based upon an incomplete understanding of your experiment's parameters. When you press your fingers (or wood slats) together, you're making the surface area (the part that can accept moisture) extremely large compared to the drop resting on the surface. As such, the reaction is able to move from one surface to the other in a very short period of time. It's not about the lack of oxygen between your fingers (which I assure you still exists).

For another experiment, take two mixer sticks and separate them by a few sheets of paper on either side. Place a drop of CA in the middle of one stick and rest the other on top. The paper ensures there's a gap between them and air can flow. Give them a few minutes and the will be stuck to each other.

[David C. Roseman]

I bought too many bottles of medium CA over two years ago, so I've stored it in the freezer, rather than the fridge. Don't know how much difference the lower temperature makes, but bottles I pull out now seem fresh as new.

David

[robert baccus]

Well you are probably right but my damp sticks with a drop of glue and clamped never did harden in 15 minutes.. Could it be that a tiny bit of moisture (in the air) is necessary but more interferes with hardening? The perfectly dry sticks adhered immediately with one drop of CA. I have great luck glueing up green sappy blanks to dry GB's but it's slow. I need an aspirin.. I'm calling Madame Ledouche--this is witchcraft.

[robert baccus]

My recall of oxygen was in error. Talked to the factory and moisture is necessary but excess will make a joint weak or not set up. I guess wiping with a damp rag was too much. Here in the South humidity is always high which is obviously enough--desert climates often require dampening the wood the man says. A dry day here is 80% humidity. The oxygen thing applies to thread lock---my bad.

[John Coloccia]

The oxygen thing applies to thread lock---my bad.

That's interesting. I didn't know that. Did they mention anything else about it? It can't just be lack of oxygen or the stuff would immediately harden in the bottle. Maybe it interacts with the metal somehow too? Inquiring minds want to know!

edit:
I was curious...I wouldn't sleep tonight until I figured this out.

http://www.henkelna.com/us/content_data/168592_LT4985_Threadlocking_Guide.pdf

Interesting read. Somewhere in small print, it says that Loctite cures in absence of oxygen AND the presence of metal ions. Apparently, there's also a primer for inactive metals. :)

[Jeff Nicol]

I use just plain acetone, but it has to be in a spray mist bottle as the fine mist is what I believe sets off the curing reaction. Like has been said if you just use it in a liquid form it will break it down. I did see a video somewhere on line where a guy was using a spray can of air freshener that worked well so that leads me to believe it is the small mist particles that work best.

I have some bottles of CA that are a couple years old that just sit in the shop with no lids, but the thing that I do is to make the smallest hole in the protective film on the the bottle as this will not let much if any moisture that is in the air get in. I use a sharpened piece of .030 welding wire to poke the first hole and make sure to suck the remaining glue in the tip back into the bottle at the end of the day by squeezing a little air out and then letting the bottle suction the glue back in.

Good luck,

Jeff

[Stan Smith]

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.

I've just been going through these posts since I just had to throw out a CA glue bottle that had quite a bit of glue left. I've been using those "cherry wires" to plug the tubes. They worked on some CA glues but not all. Sometimes they are very difficult to pull out. It's dry here and glue probably dries out faster. I always like to have adequate supplies of stuff on hand, but I probably store too much. I"m going to start following your advice and just buy a very small tube from the hardware store if I need it. I don't have a fridge in the garage, but I may start keeping the stuff that I have now in the fridge. Thanks for your info.

Stan

[kevin nee]

I was under the impression that when filling a gap (say burl inclusion) it would be stronger if left to cure naturally. (say overnight)
Any truth to this? Also am I the only one that ever got CA Glue an their eye glass lens?

[Scott Hackler]

Kevin, if filling a void, crack or burl with CA... it is important to remember that CA needs moisture to cure (water). So sealing or bonding to green wood is always better. Dry wood should be wet down prior to applying CA.