Yeah, for what you have there just toss a 20 or 30 g packet in each box. Theres a place in California, sellica gel factory (check spelling ). I have bought some from them still in use. Google. Also, JPs Corner is on ebay.
Well actually you can do a lot more. In my experience the small packets of silica gel one finds in shoeboxes are practically worthless. You can buy for $3 ea, now $5 ea, 40 gram aluminum boxes with an indicator. I'll try to photo one. I think the little packets are a lot less than 40g, maybe 1-2 g. Usually I just eat them. Very crunchy! Really what I need are Temp/ humidity recording monitors like they put in museum showcases.
I bought a big pack of u-line brand dessicants on Amazon. $10 for like 50 larger packets I think. I stick 5-10 in each box of coins and rotate with freshly-recharged dessicants every time I visit the bank. I live in Colorado which is actually a fairly dry state and the bank is air conditioned so they're not terribly necessary but they give me just a little more peace of mind and I have yet to see BD start forming or reactivate on any of my bronzes.
If you are the type who faithfully changes the oil in the car, desiccants will work for you. Here is the thing , you need an idea of the time your choice will no longer absorb moisture from the air in your enclosure and replace or recharge the pack, because until you do, it is now a source of moisture to cause even worse problems than no desiccant, because you will think it is "working" for you. Buy it with a moisture indicator ( usually color change chemical) so you can tell. Jim
"it is now a source of moisture to cause even worse problems than no desiccant," Not really, the SiO2 will release the water it holds only at elevated temperatures. As you can see on the canister I've photo'd it's recommended to put it in an oven at 300F. After an hour of so the water's gone and the built in indicator changes to blue. You can also judge how quickly the water gets back into your coins by how quickly the indicator changes back to pink. Also it's critical to keep sulfur (S) compounds or things with S away from coins. Some rubber bands contain sulfur, also old plastics which contain PVC. Additionally lower temperatures are preferred and for high end sensitive coins, storing them without oxygen is also good.
Yes, pretty sure this is correct. When the moisture absorbed by the desiccant reaches a state of equilibrium with the moisture in the ambient air, no more absorption (by the desiccant) takes place. But neither is the moisture released back into the air by the desiccant, unless the ambient air happens to experience a period of lower moisture concentration for some reason. Energy is required to force the desiccant to release the absorbed water molecules -- usually achieved by heating the desiccant for a period of time -- so it's not likely that the desiccant will ever become a moisture source unless the surrounding air is very dry.
Thanks for that comment @IdesOfMarch01 , I was not aware of moisture NOT being released after saturation. I have used desiccants for years for other metal storage, and have recently (last few years) begun using desiccants for coins. I had always been careful to ensure I re-dried the desiccants through an oven treatment, but had been very paranoid about saturation and possible creating a moisture environment with saturated desiccant. (I understand the caveat you stated.) Thanks.
I use the "Eva-Dry" desiccant device which is rechargeable via a wall outlet. It takes 12-18 hours to fully evaporate but in a small safety deposit box, I only have to swap it out once every few months. It indicates the absorption level via a change in color of the desiccant crystals.
I use these in my safe deposit box too, as well as in my small home safe, which is fire-retardant and thus very well sealed, promoting the growth of mold that I could literally smell when I opened it. They work very well in my home safe, so I'm confident that they're doing a good job in the safe deposit box as well.
Some of the cheap methods I've used for various reasons are: Rice in small bags in my ammo cans. Leaving a low wattage bulb burning, and golden rod for safes in the gun/valuables room. Now I just run a small dehumidifier. Of course cheap being a relative term. The desiccants are cheaper and easier to obtain now than all but the dehumidifier. This was back in the early 70's when it was harder to get desiccants and they were more expensive.
