Loctite

I have a small bottle (much depleted) from 40 years ago. Likely a different chemistry, but still works for what it was bought for all that time ago - a simple thread-locker (for engine big end bolts).

Some truloc versions have not lasted as long, but as they were not purchased by me I don’t know their history.

I used to be the MD of a company supplying chemistry to the aerospace industry amongst others. As it happens we were also a subsidiary of Henkel (who own the Loctite brand) for a while. All our products were supplied with 'use by' dates not because they would degrade over time but because it was a requirement of our customers.

The storage environment is the biggest variable in shelf life. One of our products was just a mixture of two salts, when asked for a use by date by one customer we tried to explain that in a damp warehouse one or two days at most but in a dry warehouse we could put as many millennia as they wanted! Another important variable is exposure to UV rays and the embrittlement of plastics. Likewise, some products will embrittle plastic over a period of time - HP sauce being a good example. That is why most sauce bottles have around five layers of different plastic in them.

In the end we settled for a standard two year shelf life as that was what our customers wanted. Nice little earner for us as we would then charge to take back out of date product from the customer, re validate it and sell it back to them. Deep joy.

For me, the shelf life is determined by the state of the outside of the bottles. No matter how careful I am, the outside of each bottle gradually builds up a sticky residue that is almost impossible to remove with solvents but gets all over my fingers!

Russell

Russell, I have found that the solvent/cleaner used by double glazing fitters does a fair job of this. A useful product to have in the workshop, though care is needed on some delicate surfaces. Obtainable from those factors who supply double glazing firms.

Mike