Liquid chalk, anyone making their own?

I've made liquid chalk twice and it worked like a charm. I just started reusing some I made maybe a year ago though and it's really messing up my skin, severe redness and swelling around my finger nails.

I never took note of which alcholol I used back then. My mix was just alcholol and a fine magnesium powder.  

Does anyone know which type of alcholol is best to use? Could it be that the acholol has gone bad or did I just use the wrong type?

Any tips for make a diy liquid chalk are very welcome, even very general pointers.

I make my own liquid chalk using powder chalk and 70% isopropyl alcohol. I use a funnel to get the powered chalk into a bottle then I squirt the isopropyl in and shake it around adding a little at a time until its about the consistency of yogurt. Over time it has a tendency to dry out but unless its fully solid you can just add in a bit more isopropyl to freshen it up. I have also tried using 91% isopropyl alcohol, but I don't like it as much because makes my hands feel weirdly smooth. 91% isopropyl can also dryout your skin over time and cause irritation so its worth avoiding for that reason as well.

I have never had the problem that you described with the redness and swelling, but I would guess that you either used too high a percentage of alcohol or you had an allergic reaction to something in the liquid chalk. I don't think that chalk or alcohol can really "go bad".

I also just use 70% isopropyl alcohol. I was having trouble with it drying out really fast with some cheap travel tubes I had bought at target but I experimented with a few different emptied hand sanitizer bottles and it lasts so much longer now. Bonus if you get one of the hand sanitizer bottles that has a little carabiner on it too. Some times I even prefer the half dried out liquid chalk because it dries so fast. 

I also use 70. 90 feels punchy

Try using isopropyl alcohol for a fresh batch. Old alcohol can go bad, and it might be irritating your skin. Test on a small area first!