I am preparing to display two WWII pistols in shadow boxes. The guns have sentimental value. Each box is 10" x 12" x 3" and can be made air-tight. I need to find out; how much desiccant to use (very humid in Georgia), how frequently to change it, and where to get it at a reasonable price. Is there any special prep work that would help?

http://www.veritemp.com/index.asp?cat=125537

Is a good company. I would email the company and ask them about the changing of the product.

Hopefully you have solved your problem. If not here is link to my site which might help: Silica Gel Desiccant and Acid Free Tissue Paper (http://www.preservesmart.com/products.htm#SilicaGelDesiccants) The great thing about indicating desiccant is that it lets you know when it's saturated.