....It is chalk. It absorbs moisture or loses moisture dependent on relative humidity.
Not exactly - and Yes, absolutely.
Technically it's not 'chalk' per say, but it is very very similar to chalk in the way that it absorbs and releases water.
Firstly, what methods do you use to add moisture? I'm at a loss as to what procedures to follow and how quickly it could be done. The humid bathroom idea just doesn't seems that "efficient" to me.
If you want the secrets chief, you gotta slip me a $20 or something first.
I'm just kidding lol.....
This calls for a thursday afternoon chalk lecture!
First, let me say that the amount of moisture in a cube of chalk, is
miniscule to begin with, because thats the way its made.
So any variation of that will also be slight.
Aaaaahhh silicates.....the stuff of legends. (mild sarcasm)
The real mineral 'chalk' is a silicate. Sand usually contains silicates. Quartz is a silicate. Rubies and Sapphires are silicates. Mica (as in "formica") is a silicate. And speaking of Mica, so organized are the Mica molecules that it's theoretically possible to cut a wafer of it exactly one atom thick.
The reason I bring up silicates is because in their varying forms, they are the primary ingredients in a typical block of billiard 'chalk'. There are all sorts and grades of silica based 'sands' that are used, along with talc or lime or perhaps even corn starch, but then there are two (silicate) substances in particular that really do the trick...
One is Aluminum Oxide**, also known as Alumina or Corundum. This substance is second only to diamonds on the hardness scale, so it is widely used as an abbrasive or in polishing compounds. One of the powdery forms used for billiard chalk is called Axolite.
The other is Magnesium carbonate** or magnasite. An anhydrous salt that is not quite as 'hard' as Axolite, but it has great "grit" and also serves to regulate moisture and prevent 'caking', which lets the billiard chalk 'release' and apply evenly. Like Alumina, it's even used in food grade products and cosmetics.
Both of the previous substances have what is known as excellent 'hygroscopic' properties when it comes to making chalk. They naturally attract moisture, but because of their structure, will also "let go" of moisture just as easily. (because nobody wants soggy chalk)
The only drawback is, in an arid environment, moisture will in fact be drawn out quicker than in a humid one. And vice versa, a dry piece of chalk might actually absorb too much in a humid environment.
(But keep in mind, we're still talking about tiny amounts)
Either way, the moisture content cannot actually change the "grit" factor, it will only change the consistency.
Common sense will tell you how to keep a chalk from drying out. But is it possible to rehydrate? In my opinion, yes and no.
As mentioned before, all water is not friendly water. So unless you know for a fact that the chalk's binders et al will not react or degrade when wet, any
direct contact with water could in fact be a death sentence for a given block of chalk...and....
**For the most part, just about everything in a block of chalk is
akaline. And Alumina and Magnasite specifically will react at any trace of acid.
The potential for such reactions, (and not neccessarily just from direct contact) and oxidation in particular, are contributing factors when considering how a given block of chalk may "change" over time. (not just moisture content)
Also as mentioned before, only moisture of a certain size (small enough) will naturally and readily absorb and evaporate, without making things "wet". So other than using an atomizer* in a completely sealed room, I have found no
efficient way to imitate natural humidity in the air. Not only that, but pretty much any attempt to re-create the perfect moisture level will immediately cross the economic threshold. In other words, to spend anything more than the price of the chalk is pointless, when you can simply buy a new one.
*with ultra pure water
But even if you did imitate mother nature's humidity and it worked.....what next? Your chalk will just dry out again.
If you suspect that your chalk is "too dry", (which it probably isnt) just leave it in a naturally humid place and it will eventually reabsorb moisture as best it can. You may get results overnight or it may take weeks, but just like wood does, it will "even out" to a certain level, based on its present environment.