Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: Atomic-S on 09/08/2013 05:46:33

Title: How should silocone caulk be stored?
Post by: Atomic-S on 09/08/2013 05:46:33

I have some silicone caulk that has long service life and a vinegary odor. It is difficult to reseal a caulk tube, so the next best thing is to store it in a favorable environment (while sealing it as well as can be done). I have tried this method with latex products and it extends the self life greatly. For latex products I use a humid environment created in a sealed chest. For silicone caulk, I understood that the curing mechanism actually utilizes H₂O, so a humid environment would seem most unsuitable. Any ideas?

Title: Re: How should silocone caulk be stored?
Post by: SeanB on 09/08/2013 20:01:30

Silicones generally cure from exposure to atmospheric oxygen. Sealing the tube with a plastic cover and keeping it in an air tight container in the fridge or freezer will make it last longer, but it will eventually cure from diffusion through the plastic tube.

Title: Re: How should silocone caulk be stored?
Post by: Bored chemist on 10/08/2013 14:09:39

The acetate based ones (and the smell of vinegar suggests that's the case here) cure by reaction with moisture in the air.
http://en.wikipedia.org/wiki/Silicone_rubber#Condensation-based_system
Keeping it dry will improve the shelf life. Cooling will also slow down the reaction so keeping it in the freezer works on both counts- much of the water in the air gets frozen out, and it's very cold.

Title: Re: How should silocone caulk be stored?
Post by: Atomic-S on 15/08/2013 06:03:21

Thanks for the suggestions; I guess a hot shop is not a good location.