How to keep you're Comps, Chemical etc dry

[jm82792]

I live in a wet environment, sometimes it hangs at 90% to 100% humidity for a couple dayswhile it rains then dries up to 50% humidity.

For now I've kept my small amount of comps, chemicals and finished fireworks in plastic bags with rice as a (crappy) desiccant, however I need more room and want to keep them sheltered outside.

 

Would a couple 5 gallon buckets with some O rings or something to make a really tight fit and say 50 grams of silica gel per bucket work to keep my pyro stuff dry ?

 

I know that silica is ineffective if fresh air gets in,

I think it would work but I don't want to find out that it did not

[Ventsi]

Buy some Calcium Chloride, it supposed to be sold at big stores such as walmart and such. Put a few hundred grams inside a small pouch and tape it to the lid of the container. It should keep your stuff nice and dry. Also get good quality buckets, a O-ring and a good lid are key here, I keep all of my bulky stuff in buckets so it should work for you as well.

 

SiO2 will work as a desiccant too but is generally way more expensive than CaCl2 , and as far as the fresh air getting, that should not pose any problem, no idea why you think it would ruin it.

[jm82792]

Thanks for the advice,

every bit of money saved helps since it will go to buy some more chemicals.

[Arthur]

Among the esoteric building equipment I've seen was a self contained un powered humidity control vent. Simply it was a humidity sensitive element that opened a vent and closed it again. If you have some 50%days then you can open a vent then, and close it on the 99% days.

 

As an electronics project you could have a vent fan that ventilated the chem store at say 60% and less and shuts the vent at say 85%

[dagabu]

Buy some Calcium Chloride, it supposed to be sold at big stores such as walmart and such. Put a few hundred grams inside a small pouch and tape it to the lid of the container. It should keep your stuff nice and dry. Also get good quality buckets, a O-ring and a good lid are key here, I keep all of my bulky stuff in buckets so it should work for you as well.

 

SiO2 will work as a desiccant too but is generally way more expensive than CaCl2 , and as far as the fresh air getting, that should not pose any problem, no idea why you think it would ruin it.

 

No!!! Pleased don't do do that!!

 

Calcium Chloride will keep grabbing water until it is saturated and will drip down into your chems contaminating the chems.

 

Commercially, a clay such as Bentonite is mixed with the Calcium Chloride so that only a limited amount of water can be absorbed. You really don't want bone dry chems anyway, 5-12% humidity is fine for most comps while whistle likes 1-7%.

 

The other problem you bring up is the taping it to the lid, only the top of the chems will dry right away when you do that. Take a paper towel tube, hot glue a disk to one end, fill it with your desiccant, glue another disk to the other end, set it into your clean bucket and add your chems. This does a lot better job of pulling the water out and keeping the whole thing dry.

 

D

[derekroolz]

No!!! Pleased don't do do that!!

 

Calcium Chloride will keep grabbing water until it is saturated and will drip down into your chems contaminating the chems.

 

Commercially, a clay such as Bentonite is mixed with the Calcium Chloride so that only a limited amount of water can be absorbed. You really don't want bone dry chems anyway, 5-12% humidity is fine for most comps while whistle likes 1-7%.

 

The other problem you bring up is the taping it to the lid, only the top of the chems will dry right away when you do that. Take a paper towel tube, hot glue a disk to one end, fill it with your desiccant, glue another disk to the other end, set it into your clean bucket and add your chems. This does a lot better job of pulling the water out and keeping the whole thing dry.

 

D

 

 

What about a food dehydrator would that be near perfect for drying pyrotechnics, or does anything get to hot?

[firetech]

That works derek, but unless you have a ton of dryers you won't have enough space to store all of your chems. Most dryers are used once to dry wet comps faster than normal air would do and then the comps after are stored in a dry place.

[jm82792]

Okay I have a good amount of Bentonite clay,

since I just need to bring the humidity down since stuff tends to get super saturated from the nightly rain....

 

I don't think I'd go with an automatic vent since I'm not going with a whole lot of chemicals,

just 3 or so 5 gallon buckets worth and some of that would be for finished fireworks.

 

I'm looking for a dehydrator since I'd like to dry stuff out quickly.

Has there been much of an issue using one with an extension cord away from the house and somewhere where a fire wouldn't be an issue ?

 

Thanks for the help,

Josh

[Arthur]

If you have snap top buckets then you can get an indicating silica gel dryer pouch for each bucket and one spare. Put one (or more ) in the oven after a meal is cooked to dry out the gel for reuse. Keep dried pouches in a snap top bag.

[jm82792]

That's what I originally thought,

I can get 150 grams of silica gel for $10 shipped and that could do 2 buckets.

When my hygrometer reads higher than I want then I'll bake it for a couple hours then put it back after it's done cooling.

[Ventsi]

You could go to a Harbor Freight store and buy a few lbs of silica for $10.

Or get some from your local Michaels for drying flowers[its not color changing].

[jm82792]

I'm on the Big Island of Hawaii,

there is not much out here, what is locally available is somewhat to really expensive since living costs are high out here,

and everything has to be barged out here.

So it's what I can buy with eBay or some other place online,

plus UPS and Fedex are ridiculously expensive, so I'm stuck with USPS.

Edited November 22, 2009 by jm82792

[dagabu]

I'm on the Big Island of Hawaii,

there is not much out here, what is locally available is somewhat to really expensive since living costs are high out here,

and everything has to be barged out here.

So it's what I can buy with eBay or some other place online,

plus UPS and Fedex are ridiculously expensive, so I'm stuck with USPS.

 

For keeping chems dry in buckets I still recommend the Bentonite and Calcium Chloride, easy, cheap, disposable or reusable.

 

D

[jm82792]

I'll go with Bentonite and Calcium Chloride,

cheap, easy to get and you're endorsing it

[Swede]

I also like the use of heavy PE bags INSIDE a bucket or HDPE container. The best bags are plain but thick, non-ziploc, using twist-ties to close. Inside a bucket, the chems are pretty much immune to outside humidity. For certain chems like ammonium nitrate, I double-bag those, and they remain free-flowing indefinitely.

 

Silica gel is not a bad notion, and I use them, but they seem to saturate very quickly. There are sealed silica gel bags and metal containers that are sold for storing firearms, and they do work well, but it seems that they go "pink" pretty quickly, like a week or two. I weighed a small silica gel container, and it went from 24 grams dry to maybe 40 grams saturated, which is only enough to keep an individual bucket dry. They are expensive, but they at least can be restored in an oven very easily.

 

I would skip calcium chloride, inside or outside a container. Messy. I have a closet-sized room for storage, and even a large amount of calcium chloride saturates in a couple of days. In the end, I added a cheap dehumidifier, about $90, and it pulls about a gallon of water every two days from the air in this small room. An added benefit is that in winter, it keeps the room warm. So if you can afford it, a dehumidifier rocks.

[derekroolz]

I would skip calcium chloride, inside or outside a container. Messy. I have a closet-sized room for storage, and even a large amount of calcium chloride saturates in a couple of days. In the end, I added a cheap dehumidifier, about $90, and it pulls about a gallon of water every two days from the air in this small room. An added benefit is that in winter, it keeps the room warm. So if you can afford it, a dehumidifier rocks.

 

 

Well if the water is clean enough you should drink, not trying to be an eco freak. But it would be a pretty cool way to tell people where you get your water.

[Mumbles]

Well, that is a moronic idea.

 

Now a more reasonable one. There was a discussion on PML a few weeks ago that as usual mutated into something completely unrelated to the original topic. It started as Sr(NO3)2, went to an english plant exploding from wetting a chlorate comp with hard water (Ca(ClO3)2 production), and went to clean water supplies. Someone mentioned that they use the water they retain from their dehumidifier as the solvent for wetting their compositions. It is in essence a crudely distilled water.

[dagabu]

I also like the use of heavy PE bags INSIDE a bucket or HDPE container. The best bags are plain but thick, non-ziploc, using twist-ties to close. Inside a bucket, the chems are pretty much immune to outside humidity. For certain chems like ammonium nitrate, I double-bag those, and they remain free-flowing indefinitely.

 

Silica gel is not a bad notion, and I use them, but they seem to saturate very quickly. There are sealed silica gel bags and metal containers that are sold for storing firearms, and they do work well, but it seems that they go "pink" pretty quickly, like a week or two. I weighed a small silica gel container, and it went from 24 grams dry to maybe 40 grams saturated, which is only enough to keep an individual bucket dry. They are expensive, but they at least can be restored in an oven very easily.

 

I would skip calcium chloride, inside or outside a container. Messy. I have a closet-sized room for storage, and even a large amount of calcium chloride saturates in a couple of days. In the end, I added a cheap dehumidifier, about $90, and it pulls about a gallon of water every two days from the air in this small room. An added benefit is that in winter, it keeps the room warm. So if you can afford it, a dehumidifier rocks.

 

Swede,

 

Agreed, dehumidifier for large areas, closed containers, I will stay with CC/Bentonite in paper bags.

 

D

[Swede]

I don't think dehumidifier water is very clean unless the unit is modified. The air in the room is pulled across the cooling grid, which then collects all sorts of airborne crap, including airborne soluble chems like nitrates, and all that ends up in the water. To make a dehumidifier create decent water, I think you'd need to HEPA filter the air that goes in, and keep everything squeaky-clean on the collection side.

 

The collection container tends to get a bit of microbial growth going, too, after a few weeks of work. Maybe I need to add some benzoate to keep it from getting too slimy! But it definitely works, and gives me a digital readout of the current RH. I normally set it for 40%. When rainy/foggy weather rolls through, walking into that room, I am struck by how crisp and dry the air is.

 

But it is not a cheap alternative and only works if you have an enclosed space.