If you are like me then Super Glue is one of those things that’s a bit of a two edged sword – you need it but it’s messy to use and never seems to last! Sometime ago I came across the tip to always store your open super glue tube (or bottle) in the fridge, as the cold helps to preserve the glue and stop the methyl/ethyl/propyl alpha-cyanoacrylate from aging or whatever.
However just recently a consumer affairs show on New Zealand Television had a couple of further tips about super glue.
Unopened Super Glue should apparently be stored in the Freezer – manufacturers have a huge variety of shelf life, anything from 6 months to 2 years from date of manufacture, and this probably relates to which compound or variety of alpha-cyanoacrylate they have used (i.e. methyl, ethyl, or propyl). Anyway – freezing the unopened tubes (or bottles) will ensure they last the maximum period and possibly longer prior to being opened.
Opened Super Glue deteriorates very quickly, and although you might think it’s still gluing things fine 2 months after opening, in fact it’s ability to maintain the joint is degraded and increases the likelihood the join will fail (i.e. the longer it’s open the less of the ’1 tonne’ it will hold. Have you ever noticed sometimes you glue a cavalry figure onto his horse but every time you touch him he breaks off again? Likely this is due to old glue as much as dirty surfaces, paint, or other factors… I have understood for some time that storing the opened tube (or bottle) in the refrigerator will prolong the life and quality, however apparently the best way to store it is in a sealed container (e.g. screw-top glass jar) with a silica-gel sachet to keep it company (i.e. one of those moisture absorbing sachets that come inside boxes of new electronics, or laptop bags, or so on). I am not 100% sure if the 2 methods are complimentary, but I assume not (as refrigerating might create moisture inside the jar), so presumably the sealed jar with silica-gel in a cool cupboard is the best solution.
Likely this has been covered on other shows like ‘Myth Busters’ previously, but some other interesting facts were that some brands of Super Glue really do hold a ‘tonne’, or more, depending on the material (in the New Zealand test gluing 2 pieces of metal one glue brand withstood 1440Kg (i.e. about 3200 lbs) of stress before failure, but other brands withstood as little as 700Kg (1500 lbs) – again this probably relates to the compound used as much as ht equality of the manufacturing process.
For more reading there is a reasonable article on (the amazing) Cyanoacrylate at Wikipedia.