Thread: Basic safe lighting and dehumidifying project

Originally Posted by Mr Browning

How often do you have to charge the dehumidifier on average?

Running the same one and it is once a week for a six gun safe, not too humid place but can be bad for condensation.

If leaving for longer periods I top up with disposable ones.

Originally Posted by Mr Browning

How often do you have to charge the dehumidifier on average?

FWIW - Mitre 10 sell the same dehumidifier for $20.

Raising the temp is a good start to dehumidifying but you also need to vent, keeping the humidity down is part temp and part air flow. Just bringing up the temp inside of a sealed up safe just means the moist air inside it is warmer - which is the ideal breeding ground for rust. A couple of holes near the bottom of the safe, and a couple near the top will mean that the bulb heat should draw cold air in at the bottom and it will pass out the top slightly warmer.

I run a small 12v PC fan 24/7 in one of my safes and that works well. For lighting I run 5 of these (bloody bright!) on a micro switch so they turn on when the door is opened https://www.aliexpress.com/item/4000...archweb201603_

I haven't had time to do anything decent in my Liberty yet so just run the disposable packs in it and change them out every month or so.

PIR's and alarm reed switches are only rated for a few milliamps so will burn out, you will need to drive a relay to handle the current.
i will supply one if you want it, pretty sure i have some reasonably grunty 12V supplies here too

Originally Posted by Mintie

FWIW - Mitre 10 sell the same dehumidifier for $20.

Yeah bought 3 on special from M10 and my experience with them is they are hopeless.
My safe is already in a very dry environment but the indicators on the units change colour within days indicating they heed to be recharged.
I also don't think they contain a vast quantity of gel crystals.

As I said, that is my experience, YMMV.

I bought silica gel from these guys https://www.silicagelproducts.co.nz/. have them in the safe, ammo safe & with the reloading supplies out in the shed. Recharge them in the oven. Seem to work well.

Originally Posted by Mintie

Raising the temp is a good start to dehumidifying but you also need to vent, keeping the humidity down is part temp and part air flow. Just bringing up the temp inside of a sealed up safe just means the moist air inside it is warmer - which is the ideal breeding ground for rust. A couple of holes near the bottom of the safe, and a couple near the top will mean that the bulb heat should draw cold air in at the bottom and it will pass out the top slightly warmer.

I run a small 12v PC fan 24/7 in one of my safes and that works well. For lighting I run 5 of these (bloody bright!) on a micro switch so they turn on when the door is opened https://www.aliexpress.com/item/4000...archweb201603_

I haven't had time to do anything decent in my Liberty yet so just run the disposable packs in it and change them out every month or so.

I admit I'm definitely on the edge of my knowledge here in terms of humidity and rusting, but since warmer air can hold more moisture, as it warms the relative humidity decreases with all other things being equal, meaning that water shouldn't want to condense out of the air onto metal. Also the light bulb should over time warm up the firearms themselves, reducing likelihood of condensation on them when the air temp drops in the house overnight or with a weather change. In effect I'm not really removing moisture from the cabinet, just altering the conditions to the degree that rusting won't take place.

Edit - where I'm unsure is whether the fact that the safe isn't fully sealed will mean the warm inside-safe air will just pull more moisture from outside. If it doesn't, my relative humidity will drop as the inside temp rises, meaning the air will be effectively drier in terms of available moisture for rusting. If it does pull outside moisture, then I have to hope that I don't climb considerably over 60%, where rusting really takes off. I'll toss a temp/rh sensor in there to see what happens... maybe will leave one outside at the same time if I get my act together.

I'm a bit stuck with the venting since I can't cut big holes in the safe, so air movement will always be limited without a major change to how the safe is designed. I considered gutting a dehumidifier down to bare bones components and putting it in there and run a drain hose out through the floor of the safe, but in the end the heat it gave off would likely be enough, and in that confined a space I could realistically risk cracking wood stocks. Even with just a miniature bulb there's a real risk of drying things out, so I'm going to have to play with the bulb wattage or add a thermostat like @2post suggested. In a bigger safe, or gun room for that matter, I would definitely start targeting airflow and humidity directly.

Are you running those light strips off a battery or external supply?

Originally Posted by canross

st suggested. In a bigger safe, or gun room for that matter, I would definitely start targeting airflow and humidity directly.

Are you running those light strips off a battery or external supply?

Mine run from a 7ah 12v Gel that is solar charged,

May be too high a wattage, but I've seen similar installed inside the church piano - does a good job.
https://www.bunnings.co.nz/dampchase...eater_p0448989

everything i was going to say has already been mentioned.

I'd personally get some chinesium Colour led strips. they look pretty cool

Best thing for raising temperature is the small 230v console heaters that are used in dairy sheds. Can get them at any electrical wholesaler, they’re only about 30-40watts and work perfectly