CaCl Moisture Absorber

[MFstooges]

This is probably a dumb question but I'm asking it anyway. If I can't get my hands on silica gel, how safe is it to use CaCl based moisture absorber for let's say 1 month?
How long until the chloride vapor invites rust on metal parts?

 

[4season]

This is probably a dumb question but I'm asking it anyway. If I can't get my hands on silica gel, how safe is it to use CaCl based moisture absorber for let's say 1 month?
How long until the chloride vapor invites rust on metal parts?

It's been ages since I've studied chemistry, but in this application, I'm pretty sure CaCl is stable, nontoxic, and does not emit chlorine gas.

OTOH, should you wish to break the stuff down into it's constituent elements, this might prove helpful:
https://patents.google.com/patent/US6994836B2/en

 

[grahamp]

CaCl is not as powerful a desiccant as silica gel, but the biggest problem with it is that as it removes water it forms a liquor that has to be contained, and then disposed. With silica gel you can toss it in a bag, seal up your item, and store it any way you like - even wet, silica gel is just granules.

What do you need to keep dry?

 

[grain elevator]

I would not worry about chlorine vapour at all. Are you aware that common table salt is a chlorine salt as well? Are you worried about having that in your kitchen?
I would fear, however, that the salt itself, as corrosive dust, may get out of the container. Can anyone shed light on this?

 

[Disconnekt]

I got one of these, a Barska dehumidifier (here: https://shop.barska.com/products/re...CTHWJPsZTv7GI6kNP3hUDRnjnRv1ngh2_Na8ktaPGExoF, you can find it a few bucks cheaper at other places like b&h, bestbuy, etc.), I got that specific one due to being able to just throw it in the microwave for a couple minutes to dry it out, compared to the ones in metal containers where you have to put it in the oven to dry it out.

 

[Steve Goldstein]

I’ve used a similar product called DampRid (or something like that) in a safe containing firearms and camera equipment for decades and have never had an issue with rust. The CaCl2 dessicant does eventually get consumed and needs to be replaced without spilling any of the liquid that’s sucked out of the air. People also use this stuff in boats that are sealed up for the winter, in autos stored for long periods, etc.

Some of the products are scented, I’d avoid those.

 

[MFstooges]

CaCl is not as powerful a desiccant as silica gel, but the biggest problem with it is that as it removes water it forms a liquor that has to be contained, and then disposed. With silica gel you can toss it in a bag, seal up your item, and store it any way you like - even wet, silica gel is just granules.

What do you need to keep dry?

Lenses & cameras

 

[Kilgallb]

I saw a lecture by a Nat-Geo photographer who was taking photos of birds of paradise in Borneo. They packed cameras and computers everyday on a cooler loaded with Silca packs. The big advantage was the silca packs could be put in an oven and baked once they got too damp and reused.

 

[GLS]

The correct formula is CaCl2.

Calcium chloride is not a terribly good choice for a desiccant in this instance, because it is deliquescent. i.e. it will absorb so much water that it dissolves itself, forming a thick syrupy solution which will easily cause a mess.

 

[MFstooges]

The syrup is contained in the lower part. After testing it seems to perform better. It quickly brought the humidity down from 70% to 43%.

 

[Shaps]

I don’t know where you live, but something like this works very well fir me.

Amazon.com

I live in humid Hawaii and have used one in my safe where Inkeep my cameras and lenses for 30 years. I replaced the solid shelves with wire shelves for better air circulation and put the rod on the floor. I just close the very heavy steel doir on the cord with no problem.
in the late ‘60’ while living in Micronesia for two years I kept my camera gear in a closet with a 60 watt ? light bulb turned on the flood. You only need to raise the air temperature about 10 degrees in a closed area to burn off humidity.