I did exactly what you're planning about 8-9 years ago. I was given a big (5200# I was told) Mosler Safe that was once the business safe for a Chevrolet dealership here. I had to hire a roll back car hauler to move it for me.
Anyway, I stripped all the old wooden shelves and pigeon holes out of it an cleaned the interior good, then cut a tight nap carpet and glued it to all interior surfaces with 3M spray adhesive. Before doing so I drilled a 3/8" hole through the floor, in a corner, with an extra long HSS drill bit. It went through the inner floor, insulating material (it looked like a mixture of concrete and asbestos?) and the outside floor with ease, probably about 9 inches total thickness. I ran the cord for a large Goldenrod through the hole and put the plug on the end outside. I didn't bother building any racks or shelves, not wanting to take up any space. I just lean the guns up against the walls and haven't had any problem. I find I can squeeze more in there by not having any racks or shelves. You may rather have them, however.
The carpet has worked great and everything stays warm, dry and toasty from the heat off the Goldenrod. This is Georgia, and extremely humid, commonly running in the mid 90% level all summer. You could use the 3M adhesive, or some other construction adhesive like Liquid Nails to put paneling in it, but I prefer the carpet.
Good luck, Stan
Stan and all you guys with old antique safes. Last year I talked with a safe man about my antique safe. I complained to him about how the inside always smelled of mildew. He asked me how thick the walls were. I told him about a foot thick. He then told me that this was an old bank safe and the interior was a moisture impregnated concrete lining. The reason for it was in case of a fire the concrete would give off moisture to further protect the contents of the vault. Consequently my vault will always stink. He also asked me if the doors had a felt lining in a groove close to the edges. I told him yes. He then said that this was to prevent a safe cracker from using nitro to blow the doors off. The felt would wick up the nitro and expand thus sealing it keeping the nitro from going all the way around the doors. The only way I would keep a gun in there is if it was vacuum sealed in heavy plastic. I now have a 4000 lb. paper weight sitting and stinking in the corner of my garage. J.R.B. jerb
