Dry z air/salt based desiccant
- Thread starter Twinsig
- Start date
Salts control humidity by causing it to try to dissolve the salt, which does not happen below a certain critical RH range. So they remove excess humidity down to the dissolving range (changes a little with temperature) value and hold it there. It gets no drier beyond that point. It works pretty well to regulate RH at a reasonable level, but I would not use salts near my firearm finishes unless I knew what it was. Having it in a container that isolated the salt is a good idea. It needs to be water and corrosion-proof on the sides and bottom. The more surface area you give the crystals, the faster it will work. If it ever dissolves in a puddle, it has taken all the water it can and you need more.
In general, surface rusting of steel drops off dramatically at about 60% RH and below. Below 40% RH, even salt spray that has dried on steel will not corrode it, but that's getting too close to dry enough to crack wood stocks, which survive 50% much better. So I target 50%, which is what the Dry Z air salts claim to hold to, and I supplement with rust-inhibitive oils or wipes.
Personally, I bought a cheap digital humidistat on eBay and let it control a heater. You have to heat air very little to reduce its RH. Usually, 20 degrees is enough. You can try it out on this calculator. First, put in the RH you actually have and the room temperature you actually have. It will calculate the dewpoint. Then clear the temperature and RH and put 50% in the RH and let it calculate the temperature from that and the dewpoint if found previously.
Example: my basement can get to about 85% RH at about 70 degrees. If I plug those numbers in, I learn the dewpoint is 65.28°F. I leave that in place and delete the temperature and the RH and put 50% into the RH window and tell it to calculate. It tells me I need the temperature in the safe to be about 86°F to bring the RH down to 50%. That means heating it 15°F inside, which a couple of 100 Watt incandescent light bulbs in series will do without getting bright enough to burn out any time soon. I let the humidistat control the bulbs.
In general, surface rusting of steel drops off dramatically at about 60% RH and below. Below 40% RH, even salt spray that has dried on steel will not corrode it, but that's getting too close to dry enough to crack wood stocks, which survive 50% much better. So I target 50%, which is what the Dry Z air salts claim to hold to, and I supplement with rust-inhibitive oils or wipes.
Personally, I bought a cheap digital humidistat on eBay and let it control a heater. You have to heat air very little to reduce its RH. Usually, 20 degrees is enough. You can try it out on this calculator. First, put in the RH you actually have and the room temperature you actually have. It will calculate the dewpoint. Then clear the temperature and RH and put 50% in the RH and let it calculate the temperature from that and the dewpoint if found previously.
Example: my basement can get to about 85% RH at about 70 degrees. If I plug those numbers in, I learn the dewpoint is 65.28°F. I leave that in place and delete the temperature and the RH and put 50% into the RH window and tell it to calculate. It tells me I need the temperature in the safe to be about 86°F to bring the RH down to 50%. That means heating it 15°F inside, which a couple of 100 Watt incandescent light bulbs in series will do without getting bright enough to burn out any time soon. I let the humidistat control the bulbs.
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I'm not putting a container of salt , which yes it does absorb water ...in with my guns ....
Salt + Humidity = Corrosion ...Corrosion and firearms / ammunition just don't play well together .
I'm not smart like Unclenick , and don't have any facts , figures or charts ... I just don't see salt being a good desiccant to put with my guns .
Gary
Just a dumb Cajun from down the bayou .
Salt + Humidity = Corrosion ...Corrosion and firearms / ammunition just don't play well together .
I'm not smart like Unclenick , and don't have any facts , figures or charts ... I just don't see salt being a good desiccant to put with my guns .
Gary
Just a dumb Cajun from down the bayou .
It's not table salt (sodium chloride). I wouldn't let that near a gun, either. This is some other kind of "salt", as chemists use the term to mean an acid whose hydrogen has been replaced by a metal. From this table of salt saturation humidities, I would guess it might be magnesium nitrate, which is the "salt" that results when magnesium replaces the hydrogen in nitric acid by reacting it with that acid.
I used a "salt" based dehumidifer in my gun safe and accidentally knocked over the container that held the liquid derived from the process. It drained down the side of the carpet cover into my Winchester 101 O/U 20Ga shotgun and completely froze all of the mechanics, created the need for a gunsmith to revitalize it. All was accomplished except for one chamber that will not auto extract the fired round.
Now I use units marketed by Remington that plug into a wall socket to activate the crystals; when blue, the unit goes into the safe until they turn pink.
Now I use units marketed by Remington that plug into a wall socket to activate the crystals; when blue, the unit goes into the safe until they turn pink.
Great info as usual. Thanks y'al!
Uncle, you must be one of those over-achiever type dudes!
There's a guy on a bmw moto forum called Dirtrider, he knows every freekin thing about those complicated bikes!
And KDXgarage on the kdxrider forum!
Yeah, I'm still ridin at 56. Not near as good though, but who cares. There's no Rewind button on life. There IS Pause. But not rewind!
Uncle, you must be one of those over-achiever type dudes!
There's a guy on a bmw moto forum called Dirtrider, he knows every freekin thing about those complicated bikes!
And KDXgarage on the kdxrider forum!
Yeah, I'm still ridin at 56. Not near as good though, but who cares. There's no Rewind button on life. There IS Pause. But not rewind!