I bought a high quality large gun safe and it has worked well. Better have your floor reinforced or have it on a slab, but the quality I found to be better and they are geared for intrusion blocking. Mine is fire rated for 90 minutes and a crook better bring a lot of burn bar equipment if he thinks he can break in. It is also big enough to house anything I could buy, but I will need to sell it with the house because there is no way to get it out. Probably weighs 1,000 pounds empty.
Off topic, but if you're going to use Amazon, you might as well use smile.amazon so when you buy things a small portion of it will go to a charity of your choice.
Ok, my rechargeable dehumidifier came in. I put it in the safe with some color changing silica packs to see it it works. Also I just found out I can microwave my silica packs for 3 minutes and they turn back to blue meaning they are good to go again.
I checked out some Walking liberty coins I had since the 90s the ones in decent holders were ok but I had some PVC holders from the 90s also that turned the edges Green they were all lower grade coins. Moisture is the biggest trap air out your safe like 1 once a month anyway and tape off BCW holders at the worst some of my silver bullion is milkspotting but it depends on the coin. Stuff I bought in January like the JM bullion Wolves are fine yet in Taped off BCW holders.
Silicon packs are a waste of money if anything drills some holes in the safe. Or just open the door twice a month Stapled holders are bad just too risky Black Foam Guardhouse holders are ok but leak in moisture and turn the edges black from the foam some coins they are ok with. I still say Vinyl flips are the best if they are PVC free and taped off at the end or Saflips or Guardhouse flips. Or airtight holders are the best but I think they cost too much and take up alot of space in a safe. Whitman Folders suck I used to have those they just turn the edges of coin GREEN from moisture.
Have a couple of different safes in my house coin and gun and never store one In the other, its a completely different environment, if your having problems with your packs and you have noticed them filling up faster you may have a small cover leak.
If you open the safe more than once a week, any leaks are probably insignificant. If you only open it a couple of times a month, the only leak should be at the door edges. One of my friends had a safe with gaps, so he used black electrical tape to seal it. He would just peel it off to open and put new tape when he was done. Acetone will remove any excess adhesive. You can weigh a fresh drier pack, and after a period of time re-weigh it before recharge to see how much water is absorbed from the internal air.