shelf-life of silicone rubber

[wooden_reefer]

If silicone rubber is too old it fails to cure.

What do you think is a common shelf-life?

[toothybugs]

You mean like silicone caulking/ adhesive/ sealant? Forever, unless it gets access to moisture at which point it'll cure.

[uncleof6]

Ummmmmmmmmmm, hate to start another debate, but the curing mechanism for silicones has a very definite shelf life, and that includes GE silicone I and II. It can vary from 1 - 2 yrs, depending on the formulation, and reality based storage conditions. Momentive puts a manufacturing code on the tubes, it is a bit hard to decipher, but the translations are posted here on RC. In actual practice however, because storage criteria are rarely met once the material leaves the factory, it seems that about 1yr and it is done, for the silicones most commonly used, especially for the high grade adhesives (RTV100 series.)

[BeanAnimal]

I wouldn't use a tube of Silicone I or II that is more than a year old. Nothing worse than a sticky non curing mess. I prefer II, but its cure properties allow open tubes to harden rather quickly if you don't fully seal the end of the open tube.

[toothybugs]

This is interesting. Mainly because I've never had a problem with stored tubes. Learn something every day.

[sleepydoc]

It depends on the adhesive, on the storage conditions, and what you are asking the adhesive to do. 'old' tubes may be fine, or they may not, depending on the above. If it's a critical application that's difficult to do or to repair, you're probably better off not risking it and getting a new tube. $6-8 for a new tube is not worth the risk, IMO.

[NanoReefWanabe]

It depends on the adhesive, on the storage conditions, and what you are asking the adhesive to do. 'old' tubes may be fine, or they may not, depending on the above. If it's a critical application that's difficult to do or to repair, you're probably better off not risking it and getting a new tube. $6-8 for a new tube is not worth the risk, IMO.

just be sure on the manu. date, as many people have bought "new" tubes of RTV and SCS from grainger wait a couple days for it to arrive to find it well expired ...

[uncleof6]

just be sure on the manu. date, as many people have bought "new" tubes of RTV and SCS from grainger wait a couple days for it to arrive to find it well expired ...

Grainger is pretty bad when it comes to turning over their stock, and storage conditions are not met. Generally what they send you is already a year old... nope sorry, not useful at all...

Bottom line is don't mail order. There are many many Grainger brick and mortar establishments, both in the US and internationally.

[BeanAnimal]

Grainger, like McMaster or any other national supply house, does not do well with perishable stock in small quantities. Large jobs that use case/pallet lots get fresh from the factory (usually) but the onesies and twosies end up being shipped from some regional warehouse shelf that may or may not be fresh, based on recent regional demand.

You are still far better off with them than you are some no-name etailer who drop-ships stock from who-knows where but more than likely new-old-stock that was sold off near expiration, at steep discount.