Secure safe, but dry?

Here we go again! How many times opening the safe house we found ourselves in the hands of documents, cards or other objects completely soaked, moldy or damp oxidized.

This is a fairly common problem, due to the location of safes, often embedded in exterior walls facing north or perhaps victims of rising damp from the ground or buried. 
The fact is that to pay the expenses are just THOSE documents very important or THAT ' object in which we kept in a special way .

How to tackle the problem of moisture.

Inserting desiccant bags of silica gel or bentonite can offer us tangible help to counteract condensation and moisture accumulation, both in safes and in small armored cabinets.

How many desiccant bags do you need? Indicatively for small safes it is advisable to use at least two sachets of 120 grams of silica gel or 270 grams of bentonite, however for safety it is preferable to exceed the dosage, this because the absorption capacity and the saturation time of the desiccant sachets are directly connected to the relative humidity of the environment to be preserved, the environmental temperature and the amount of air exchange with the external environment.

Each time the safe is opened, a new influx of moist air is created, the desiccant sachets will be continuously subjected to new work cycles that will lead to rapid exhaustion.

Can I regenerate them and continue to use them? the best way to know when to regenerate sachets is to check their weight after a few weeks, knowing that the maximum amount that can be absorbed is well determined for each sachet format. This means that when it reaches a certain weight, the sachet has exhausted its absorption capacity and will therefore need to be regenerated in order to be reused. Be careful though, the sachets with Tyvek wrapping cannot be regenerated, furthermore it is good to remember that although silica gel is an inert and non-dangerous material, home ovens should not be used to regenerate it, to avoid any possible contact with food.

For example a 120 gr sachet. TNT can absorb about 20% of its weight (24 g), so when it weighs 144 g it means that it is exhausted and needs to be regenerated. See table below

A further measure, which can be combined with the use of silica gel in the safe, is to strengthen the protection of documents and materials paper, which by their nature absorb like sponges every drop of moisture, placing them in a closed plastic bag rather thick ( eg briefcases) with some silica gel sachets from 5 or 2 g.