my safe has 2 AC plugs in the inside.  is it a bad idea or not for an active dehumidifier?  any problems with static charge or anything else that would be bad in a safe?

Ive got 6 of those small non-electric ones that you reactivate in the oven, but they seem to need to be redone every week.

Where is the water going to go?  If it goes into a tank, it will evaporate again, and you will be taking the same water out of the air, over and over.

Get a golden rod, much safer.
I've read some horror stories about the rechargeable ones.
They might work fine but the golden rod, you plug it in an forget about it.
It works by slightly raising the temperature and that's it.

I wonder if you put some 49% Boveda packs in the safe?

I didnt realize this until a few minutes ago, but the entire concept of a goldenrod is absolute horseshit.  Their schtick is "it raises the internal temps, and then the warmer air seeps out the cracks, taking the humidity with it."

So I got 2 temp/humidity sensors from amazon a few weeks ago.  Set them both up outside the same as a control for a few days, they agree identical in readings.

stuck one in the safe with 6 of those small pellet absorber deals that you heat in the oven for a few hours when they change colors:  humidity in the safe at 59%, humidity outside the safe is 60%.  I read that safes should be 30% - 50% so this isnt good enough.

which is why I gave the goldenrod a whirl.  got the 36" one and its almost too wide but sits just right (60x40x27 homeland safe).  plenty of airspace around it as well.  

after 12 hours, the temp in the safe is now 3.5deg higher in the safe like they say, but also the humidity in the safe is now also higher, at 61%, even higher than the humidity outside the safe.

that goldenrod is actually very warm to the touch, so that plus the temp difference proves it is operational.

what a hunk of shit, actually *higher* humidity now?

I run a golden rod in my safe, which is in the master bedroom. I also run a cool mist humidifier during the winter.

My guns have no rust or corrosion. Maybe it's the rod, maybe it's not.

i dunno?  i guess the laws of physics dont apply in my closet where the safe is.
now i do frequently miss some mundane detail, but theres no decimal points involved here.
i dunno

I have a Liberty Lincoln 50 that is bolted to the slab in our garage that is not insulated located in the Houston area.

It’s been there since 2013 with the largest Golden Rod made.  No issues of rust or corrosion.

My safe stays nice with the rod and lower humidity than the outside.  I'll take it.

 How do people not understand how a golden rod works?   It doesn't heat the air so the moisture moves out of your safe.... It doesn't do anything for the humidity at all.  What it does is slightly raise the temp of the metal of your guns so that they are warmer than the ambient air outside the cabinet so they don't collect condensation like your glass of ice water does because it's colder than the room temp.

This.  

It's the same, well, opposite reason you put a camera lens in a bag before going out into the heat after being in the AC.

Man it’s nice to live in Nevada and not have to worry about this shit.

the video posted above by zentradi says the opposite.
i guess this is all a bunch of divining rod science if you ask me

I just saw an ad for this stuff.  It might be worth a try, just because of the convenient packaging.

https://damprid.com/

Actually it seems you're misunderstanding how it works.

There are 2 different humidity measurements, temperature is a factor with them. Warm air can hold more water than cold air.

Absolute humidity is actual, real amount of water in the air.

Relative humidity is the amount of moisture in the air relative to the maximum amount that it can hold at that temperature. Condensation happens when objects are near the temperature at which the air can no longer hold water. A golden rod works by raising the temperature of the air, reducing the relative humidity (but not changing the absolute humidity). This means the moisture is less likely to condense out of the warmer air. Yes, the objects in your safe are also warmed to help with the condensation part but that's a byproduct of the intended result.

I think there are 2 logical explanations for the result the OP is seeing. The temp/humidity sensor he has is not very accurate or repeatable (that's to be expected unless you have high end lab grade stuff). Or, the contents of the safe have absorbed moisture and it will take some time for things to equalize (warming up the safe is drying out the contents and that moisture will eventually make it's way out of the safe through air exchanges).

The only thing that will actually remove moisture from your safe is a desiccant, and that only happens when you change out the desiccant.

I used the large naval one that's a perforated aluminum disc, and even after baking it several times, it did very little. It may be time to change the desiccant in it, but since it's sealed....?
I use the little plug-in unit that you plug in OUTSIDE your safe to dry it out, and it works well. I have a humidity gauge in my safe to watch the responses. For best effect, a small fan blowing across the desiccant would be better, since there's not much air movement in there.

Also, if you have any wood-stock weapons in there that aren't sealed/varnished/oiled, they act like huge reservoirs for humidity.

Ive come to believe the latter.

Previously i swapped the 2 meters and the same thing was indicated.  

But more recently the humidity in the safe has dropped, now 4% less than outside.  Its a new safe and maybe had moisture to begin with.  And maybe my stuff did too.  Anyway i have regularly been recharging those little 6 gel desiccant packs and i guess i finally just now got the moisture out?

I agree. I can’t fathom living in an area that I have to worry about this problem.

I can't imagine living on an area where your whole life relies on water coming from a different state via river...

There's benefits both ways... humidity stinks at times but it's a byproduct of having a climate that gets rain.

I use a multilayered approach: heat, dehumidification, and chemical.

Heat: I prefer light bulbs to Goldenrods. They are less costly and more effective at raising the temp inside the safe.

Dehumidification: EvaDry rechargeable desiccant dehumidifiers in the safe. These are recharged about monthly. A large plug in whole room dehumidifier for the room in which the safe sits and drains to the outside.

Chemical: VCI capsules in the safe, changed out every 2 years.

Goldenrods work well, even in wet areas like where I live.  

Trying to use moisture absorbers in a fairly unsealed system like a gun safe is kind of a joke around here, you need to dry them out every couple weeks or maybe a month or two.  Most fire rated safes don’t seal up that well until the fire seal gets heated up and expands to really seal it.  (Try it- push in and out on your safe door, it is not really “sealed”).  

There is always some air flow in and out of the safe when it is closed, plus whenever you are opening it.  So adding moisture absorbers might be a good addition to a goldenrod (it is what I do just because I have a bunch of the moisture absorbers), it is nowhere as good alone.  A goldenrod will do its job without maintenance as well.  

A light bulb will do the same thing as already mentioned.