Silica gel:

[TonyS]

Do any of you use it for storing silver bullion?

[kimchi]

Of course!

[Agpanda]

Yes

[DaKine]

I put some in a personal safe about two years ago; I looked back in 6 months later and there was a puddle of water in there1

Evidently the silica gel is hygroscopic and will attract moisture/water even past the point you want and keep pulling water in - uggh!

[MickD]

Used to use it for aircraft engines but it doesn't last forever.   We used to dry out the bags in an oven before re-using them.  Guessing it's the same principal.

[TonyS]

I’m retired from electrical engineering. We used it for transformer breathers and many other things. It doesn’t last forever but it can be dried out for use again, for what it costs it’s hardly worth the effort.

[sovereignsteve]

1 hour ago, DaKine said:

I put some in a personal safe about two years ago; I looked back in 6 months later and there was a puddle of water in there1

Evidently the silica gel is hygroscopic and will attract moisture/water even past the point you want and keep pulling water in - uggh!

how on earth was the water getting into the safe?

[TonyS]

A concrete floor will sweat moisture for up to a hundred years depending on the thickness. It’s the reason I put silica gel in my safe.

[DaKine]

There was NO concrete floor to the safe. However we do live in the Washington, DC area and it does have humidity.

Tony, I believe you may have missed my point - the get pulls moisture out of the ambient air. Unfortunately it keeps pulling until you have an overabundance. That is why you have to check on the silica gels and change them. How often? Nobody is sure so best to err on the careful side.

 

What I am saying is the paradox is that if left unattended, the gel can make things WORSE!

[sovereignsteve]

35 minutes ago, DaKine said:

to check on the silica gels and change them. How often? Nobody is sure so best to err on the careful side

Is it not self-indicating these days? When I used it the lab many many years ago, it changed colour from blue to pink/red as it became exhausted. Just change or re-charge it when it loses it's blue colour and goes pale pink.

Various anhydrous salts will do a similar job. I think I used calcium chloride IIRC.

[TonyS]

42 minutes ago, DaKine said:

There was NO concrete floor to the safe. However we do live in the Washington, DC area and it does have humidity.

Tony, I believe you may have missed my point - the get pulls moisture out of the ambient air. Unfortunately it keeps pulling until you have an overabundance. That is why you have to check on the silica gels and change them. How often? Nobody is sure so best to err on the careful side.

 

What I am saying is the paradox is that if left unattended, the gel can make things WORSE!

Yes silica gel pulls moisture out of the air, it’s the reason we used it liberally on chemical hydration plants. The switchgear was literally rusting away before it was even commissioned. Gel along with air condoning helped but it didn’t stop it.

Our workshop had a drying oven that would take 50kg of gel so we could dry it out ready for the next round.

[TonyS]

18 minutes ago, sovereignsteve said:

Is it not self-indicating these days? When I used it the lab many many years ago, it changed colour from blue to pink/red as it became exhausted. Just change or re-charge it when it loses it's blue colour and goes pale pink.

Various anhydrous salts will do a similar job. I think I used calcium chloride IIRC.

I’ve not seen the colour changing gel for a good few years. It was replaced by a yellow pearlised compound that doesn’t issue a dust. Silica and lungs don’t work well together.

The plants I worked on made Calcium Oxide CaO and then hydrated it to Calcium Hydroxide Ca(OH)2.

[sovereignsteve]

2 minutes ago, TonyS said:

I’ve not seen the colour changing gel for a good few years. It was replaced by a yellow pearlised compound that doesn’t issue a dust. Silica and lungs don’t work well together.

The plants I worked on made Calcium Oxide CaO and then hydrated it to Calcium Hydroxide Ca(OH)2.

The dye was probably carcinigenic.

Slaked lime. Good grief I'm showing my age again😁

[TonyS]

If I was fit enough I’d go back there. Up to the eyeballs in s**t and corruption, I was in my element.

[DaKine]

Anyway, just trying to alert all to use care with it.

 

No indicator dye on my lot - don't use them anymore though.

[Agpanda]

I use the 40g from air-tites, just put in the owen to recharge

https://www.air-tites.com/silica_gel_desiccants.htm#.XITXCaAnbEs

[sovereignsteve]

2 hours ago, Agpanda said:

I use the 40g from air-tites, just put in the owen to recharge

https://www.air-tites.com/silica_gel_desiccants.htm#.XITXCaAnbEs

Interesting, you can get the self-indicating gel from there.

[KevinG]

No I have never used it

[CosmikDebris]

I use it in my photography bag, a few medium sized sachets in various compartments. Good stuff.