Sciencemadness Discussion Board

Chemical storage cabinet

Zombie - 6-2-2015 at 19:15

I gave it a valiant effort searching but did not find an answer to my question.

I have just bought a 2 tier "wine cooler" as a storage cabinet / desiccation cabinet. The bottom is 2.5 foot tall x 1.5 wide x 1.5 deep, and the top is 1.5 square.

I intend to use the bottom section as a storage cabinet, and the top section as a desiccation chamber. They are completely isolated from each other, and both have magnetic seal gasket-ed , tempered glass doors

I plan to store common chemicals in small amounts in the safest fashion I can. ie: sealed/waxed lids on appropriate containers. Layered protection for reactive compounds/elements, ect. Mainly common acids / in solution, and bases in powder forms.

My question is, would there be any advantage to adding / building a small compartment inside the storage section to add a desiccant such as Calcium Chloride. Or something less aggressive such as Silica Gell? Something to maintain a dry / low humidity state for storage or will that create issues of it's own.
I live in Florida, and smack between the coast, and 10,000 acres or more of State Forrest/swamp land.
The average humidity is 80 - 90% here, and 100% quite often.
I believe I have to take some measure but I am unsure of exactly what.

Thanks in advance.

Had to edit... I took all the refrigeration components out of the cabinet for another project. (I see how detail oriented you all are):)

[Edited on 7-2-2015 by Zombie]

subsecret - 6-2-2015 at 19:36

Perhaps if you store acids, it would be nice to include a vapor absorber.

careysub - 6-2-2015 at 19:48

Ah humid, humid Florida!

As a college student there (to poor for air conditioning) I had to bake computer punch cards in the oven since they swelled in the hunidity, and sometimes even notebook paper (too moist to write on without the felt-tip ink spreading). My wife, as a student, worked in the chemistry department and the absolute alcohol had a way of expanding once the seal was broken (as the alcohol became progressively less absolute).

I think maintaining a low humidity chamber is a very good idea.

I suggest using silica gel, 3A molecular sieves (used by the window industry to desiccate insulating windows, among other things), or calcium sulfate pellets (Drierite) - they are all easily rechargeable and have reasonable capacity and are inert. The first and third are available in indicating form (cobalt chloride), but you only need one bit of indicator to tell if the whole batch needs recharging.

Zombie - 6-2-2015 at 20:17

I appreciate the answers. An indicating desiccant makes complete sense. I'm happy to hear I am on the right track in my thinking,

I have a question about the "vapor absorber".
I store between 8, and 20 gallons of Muriatic acid at any given time for washing fiberglass boat hulls, and molds. (case lots are cheaper). I have to keep them in a corrugated fiberglass shed away from anything metal or actually anything I wish to keep. The plastic bottles are all sealed so I realize the vapors do escape.
Now for a small scale storage of perhaps 2-3 liters in sealed glass containers ie: PTFE caps / wax strips around caps, will I still have a vapor issue?
I googled for vapor absorber, and found massive industrial equipment, and toy looking items for shoe lockers or mainly items that did not look appropriate.
Is there something that I should be looking for in particular? Does it have to be a machine or are there processes similar to a desiccant ie: activated carbon compartment(s) inside the cabinet.

subsecret - 6-2-2015 at 20:19

Sodium hydroxide will take care of moisture and acid vapors. It will become progressively more corrosive toward the container it's in as it takes on water, so store it appropriately.

Zombie - 6-2-2015 at 20:35

Well isn't that quite convenient, as it is one of the chemicals I work with, and intend to store in the cabinet.

I am thinking of building a small (2.5" x 8" x 1") perforated PTFE "box" to contain my desiccant. Do you think this is an appropriate container? Will I have to worry about any interaction of the stainless steel interior since the Sodium hydroxide will be exposed to the inside environment?

careysub - 6-2-2015 at 20:49

Yes, the NaOH is the perfect solution if you are going through it on a regular basis (Florida - people who have not lived there cannot appreciate the amount of moisture in mildew-land).

Lets think outside the box here. Could you simply store your NaOH supply (or part of it) in a regular canister of some kind with a perforated lid? You would use out of, and refill the canister when resupplying. How about a mason jar with filter paper over the top instead of a lid?

[Edited on 7-2-2015 by careysub]

Zombie - 6-2-2015 at 21:14

Mildew land is 100% correct. You can not leave the house, and turn off the AC or the walls distort. (exaggerated a little).
I could rotate it out from the lab to the shop (NaOH) but I am also considering "shelf space". Another bottle or jar is real estate. I can make 3 of these small rectangular boxes, and hang them on the underside of each shelf. I would not mind replacing the desiccant weekly or bi weekly, and I already do this with "Damp Rid" packets in the shop, and in the house.

So no expected issues re: reacting with the cabinets stainless interior?

You all put a smile on my face in helping solve an issue I was worried about. I hope I can return the favor.:D

[Edited on 7-2-2015 by Zombie]

[Edited on 7-2-2015 by Zombie]

Chemosynthesis - 6-2-2015 at 21:52

As long as your hydroxide isn't in contact with the metal, you should be fine. Be aware of eventual carbonate absorption as an indication of needing to swap out your vapor absorber, depending on how much liquid is in your container. You're not kidding about Florida and surrounding areas!

Zombie - 6-2-2015 at 21:59

you posted that just as I was about to edit, again...
I found the info on stainless, and I will post the link.
Basically it states that for my grade (304) the stainless is resistant. I will be fine.

http://www.bssa.org.uk/topics.php?article=34

I really appreciate you help everyone.
It'll be a few weeks before I assemble this complete lab but I will be sure to post picts. of the components, and things of interest as I go.

Plans include this project, a combination fume hood / laminar flow cabinet (common fan / separate routing), lab ring stands, incubator (mycology), vacuum pump, water, air supplies, integral LED bench lighting, 110 - 220 vAC power, ect... Big plans. decent budget, and lots of fun.

Thank you again for the advice.

Hawkguy - 6-2-2015 at 22:22

Although it sounds like you got some good stuff, I would recommend something underneath the cabinet maybe in case of spills?

Zombie - 7-2-2015 at 00:14

Quote: Originally posted by Hawkguy  
Although it sounds like you got some good stuff, I would recommend something underneath the cabinet maybe in case of spills?



That's a good point. I am planing on using the loopy wine racks inside but turned up at 90* to act as sort of bottle holders, and the stainless shelves (3) will remain.
I'm thinking that way bottles / jars / ect, can not tip or fall over inside.
I did not think of a containment tray under the cabinet. I do fabricate fiberglass parts, and that may be an easy solution. Most of the chemicals I will stock have little to no effect on Polyester Gell coat.
That is a great suggestion. The room I am using does have a linoleum floor so little is lost, and clean up is simple but every stone turned... Thanks!

[Edited on 7-2-2015 by Zombie]