CA glue failure....anyone else have this???

[Clisby Clark]

I bought the mutipack of 2P10 around Christmas 2008. I remember reading that the stuff had about two years shelf life. Back in January, I used some Medium by gluing a 3/8th inch thick piece of cherry ripped on a 45 degree bevel to cherry face grain-not a whole lot of surface area and half end grain- but it's still stuck on probably stronger than the wood itself. I tried to use the Medium and Thick this week and had absolutely zero adhesion. Everything else about the glue looks good it just doesn't work-it's not even tacky.

I'm not upset in any way because I feel I got what I was expecting but I thought it was odd for the glue performance just to fall off the cliff. Has anyone esle experienced this?

[Jay Jeffery]

Will it still stick your fingers together?

[John Coloccia]

It has a two year shelf life and the performance falls off a cliff. I've experienced it with other CAs, but specifically I had an entire multipak go bad on me in 6 months. I don't think the multipaks sell very well so they sit on the shelf for a long time just waiting to be sold. Anyhow, you got two years out of it. :)

[ian maybury]

There could be something else going on that has disabled the cure, but CA generally hardens up when it exceeds its shelf life - which depends a lot on the grade and the degree of contamination in the bottle, but usually isn't guaranteed for more than about a year. Especially with the faster curing grades which contain less acid inhibitor.

Yours seemingly hasn't cured up or gone stringy after two years C, so the chances are it's not a fast grade.

I guess I'm wondering if the no bond issue might not be more to do with the piece of wood you tried to bond being an acidic type, or maybe even contaminated with traces of something a little acid?

Alternatively older/cheaper CA's may use an older chemistry which won't cure on many surfaces - like more acid wood types, paper, leather and so on. It in fact wasn't even recommended for applications like these without an accelerator until the advent of the surface insensitive types like Loctite 401 in the early 90s.

Failing that it's just possible that you got a batch of material that has a quality problem - is over inhibited/has too much acid. It may work on some surfaces but not on others. It should cure with an accelerator though.

There a few variants (ethyl, methyl etc) but the liquid basically polymerises and becomes a solid when supplied with a source of free electrons - usually a by a weak base like water or alcohol - or an accelerator. (alkali) Which is why a finely controlled presence of a weak acid stops the reaction, while more or less also adjusts the cure speed. Too much acid and the stuff won't cure at all, or at least not without being bombed by lots of accelerator.

If what you have won't cure when an accelerator is applied then it sounds like a more basic manufacturing quality issue - but if the same batch of material worked before then that doesn't seem very likely. ...

ian