Where Can You Buy Silica Gel?

I threw a few of those in my two large vaults at the bank and with coins hidden at home in various places.......don't know if that's good or bad ? But if it's healthy for the coins, then I too would like to know about those silica packs....... wanna get me some !

I just bought a bunch from Brent-Krueger.

My feelings are those Silica Gel Packs are excessively over rated and can actually get you in trouble. Note any substance can only hold so much water. If you place them in a place like a safe deposit vault and just leave it there with your coins, remember once loaded with moisture, if not removed, it now is a source of moisture. They must be replaced or rejuvenated periodically or else they will leak out moisture that they can no longer absorb. Same with people that put them in safes at home or in a cabinet.
Your much, much better off just placing your coins in an air tight or as much air tight situation as possible. I've been placing all my albums in zip type freezer type bags and pushing out as much air as possible for many, many, many years. No Silica packs required.
Remember, if in a sealed container and not replaced all the time, they serve no purpose and can actually do the oposite of what you want.

Well, once silica has absorbed all the water it can, true, they're not going to absorb any more (though if the environment is stable, it shouldn't release the moisture back out again). The little pre-packaged bags you get with medication etc are designed for single-use only, but they can be re-used. Simply putting the gel in a cool (60 to 100 degree celsius) oven for an hour or two should dry the gel back off again and it's ready for re-use.

The trouble is telling when the gel is fully wet, because normally it doesn't look any different. You can get "self indicating" silica gel, which contains cobalt chloride - a chemical that turns from blue to pink when it becomes hydrated. This indicating gel is excellent for finding out exactly how moisture-proof an "airtight" container really is. I'd only advise using it in a large area, and keep it well apart from the coins.

In my younger days, I once tried packing a film tube with shiny copper coins and pouring in some of that indicating silica gel, hoping to keep them nice and shiny. After a few years, I opened it up to have a look. The gel was still bright blue (no moisture got in), but the coins had turned all kinds of funky colours - I assume from small amounts of the cobalt evaporating and redepositing on the coins.

Isn't using "plastic" or "pvc" products that are "not" for coins a bad idea ? Espicially for long term. The "acid free" thing. Certain cardboard products and plastic products can deteriorate coins I thought. Like coin tubes are the right kind........plastic bags are ok ? I know like scrapbookers and stuff similar to coin collectors need to use the right kind of box or plastic or it can do harm.

Note using plastic items such as a zip lock type freezer bag to encase an album has not had any effects on my coins for many, many years. Prior to the invention of zip lock types I just used any plastic bag, push all the air out and taped shut. If no or very little air, nothing can happen to the coins.
And the constant misunderstanding of PVC is due to the addtion of chemicals to make them soft. This substance leaks out but there is only so much that can leak out. Eventually the PVC becomes less flexible and harmless since nothing left to leak out. However, to play safe, keep away from PVC for coins. Remember most water, gas, etc piping today is PVC. Even possibly your drinking water. So will you rot away? Anyway better to be safe than sorry.