CA not drying?

[DurocShark]

I remember a discussion a while back about this, but I can't find it.

I have a large-ish bottle of medium CA I bought several months ago and used about half of. I decant it into smaller bottles for use.

I've noticed recently that the stuff isn't curing even after 2 days. I have to help it along with heat and water, or accelerator (which I'm out of). Problem is I can't get that stuff inside segmented sections.

It is stored in my garage, which over the winter is often close to freezing. But when I'm using it, the garage is around 70 thanks to my heater (or higher lately. Some "winter" February turned out to be!)

Is this temp related? Age? If it's temp, I can control that to some extent. If it's age I'll need to buy smaller bottles.

 

[marcruby]

I recently was a spectator at a discussion of what triggers CA glue that convinced me that no one really knows. I often leave bottles of CA open for weeks and months and have them go on working. Ltyle Jamieson does this intentionally, and uses the glue for attaching faceplate waste blocks to heavy bowl blanks I find the idea frightening, but I watched him do it (and did it myself in his seminar) so I'm beginning to suspect that CA loses it's strength from some other reason entirely than exposure to air.

I have heard several people say that if CA is exposed to quantities of accerant that are too small to trigger setting (like leaving the bottle open in the same area you are spraying) will slow down setting and weaken the final set. I don't use accelerant, so I can't testify to that.

I would suggest, since humidity is an accelerant, that you 'mist' your segments before gluing them and see if that helps. And avoid exposing the bottles to too much heat above room temperature. Apparenlty that has a negative effect too.

Marc

 

[leehljp]

I have had a temp problem with CA and finally fixed it. I have a small kero heater in my little shop (9X12) and usually pre-warm the shop for about 30 minutes before working by bringing the temp up to about 70°. Even then, I had to fight a pen finish. Then with an idea, I started placing my bottles of CA about 3 feet from the heater as it pre-warmed the shop. Doing this warmed the CA bottles to about 75 to 80 degrees. Finishes worked well then.

Just because my shed was about 70°, the temp of the material, paints and CA usually did not come to the average ambient temp for some time. Pre-heating the CA to about 80° did wonders for finishing a pen.

This does not address your complete problem but it helped me out tremendously.

 

[DurocShark]

Definitely worth attempting. Thanks!

 

[Gulfcoast]

--- as water is the cure medium for cyanoacrylate, and the humidity in your area (CO) is at about 18%, I would venture a guess that it is the major cause of the very slow cure.

--- cyanoacrylate is produced with an acid added as a cure retardent (prevents cross linking), with the concept of normal humidity neutralizing the acidic nature, thus causing the cyanoacrylate to cross link.

--- you can go to PERMABONDS web site (the major USA manufacturer of CA) they explain cyanoacrylates in more detail.

Joe

 

[John Eberly]

CA cure

Old CA won't cure either. The thicker the original formulation, the more pronounced this seems to be. It could be that the thin stuff just gets used up sooner though -

The glue can get kind of "ropey" - it strings out rather than coming out in discrete drops. Try new stuff - it's not worth messing with a product that's lost it's performance.

 

[NewLondon88]

I had some sheets of plastic I was gluing together .. scraps from a machine
shop. It machined beautifully and I glued two pieces together and clamped
them for two days. Even clamped, the CA didn't hold them together very well
and I started to wonder about temp. It was around 40 in the shop and I know
that it had probably gone even lower overnight. I had bottles of different
solutions that had started to break down from the cold. When it was warmed
up again, I tried the CA and it seemed to work ok.

When I went back to the machine shop to get more of those plastic scraps,
I found out they were delrin..

Did you know that machined black delrin looks just like anodized aluminum?

 

[MesquiteMan]

You problem is most likely old glue. If you have had it for months, no telling how long ago it was made. Frest CA works regardless of temp. I keep all of my extra CA in the freezer. When I need more, I take it out and use it right away. I do not even let it warm up to room temp andit will stick your fingers together just as well!

Remember, too, that the thinner the CA, the more pure it is.

 

[leehljp]

I do not even let it warm up to room temp andit will stick your fingers together just as well!

Remember, too, that the thinner the CA, the more pure it is.

LOL! :biggrin: He isn't trying to glue his fingers together. Cold CA sticks to my fingers too, but then I am not trying to build a good somewhat thick finish on my fingers either. I will agree and tend to think it is old glue, although a couple of reputable people here (on this forum) have said that age (by itself) had little to do with that aspect.

Still in cold weather, building a good finish is affected quite often by temp. It is not temp alone but something to do with relative humidity also, IMO. To me, I figure is it something like the "dew point" - a combination that is relative. That is my opinion as to why this humidity/temp thing for CA is so iffy, then you add age in it.

Curtis you live in a much dryer climate although you do get rain and humidity. Moisture is a catalyzer to some extent and everyone knows this; high humid areas probably affect the CA in its aging and temp sensitivity. We just don't have the data on that - somewhat conjecture at this point, never-the-less it does seem to relate to temp + humidity + age.

 

[DurocShark]

I just wanted to update: Warming the bottles made the difference.

Thanks!