I reciently got into this home machining using machine wax to prototype parts. On Friday evening I thought I would melt down my accumulated wax chips and recycle it. I did that on a stove top using a regular pot my wife donated for the purpose. Later on that evening I started coughing a lot and had difficulty breathing. I don't smoke by the way. Things worsened I became bedridden yesterday afternoon, with major headache, dizzyness and shortness of breath- my temperature was always normal. This morning when I woke up I seem to be fine.
I don't know, is this coincidence; maybe symptoms of a new flu bug or should I wear a mask and melt the wax only in well ventillated conditions ? Any input here would greatly be appreciated.

Interesting question. According to the material safety data sheet (MSDS) your symptoms do seem to match the effects:

http://www.sciencestuff.com/msds/C2200.html

You are describing a classic fume inhalation injury to the lung, of moderate severity.

The time course is typical.

ok thank you. I wish they had provided some information on that on their website and at least with the shipment of their product. I assumed it was safe because there were no warnings.

This is a real strange one! As a kid, I used to chew it for gum. Made about a gazzilion candles. Had my skin covered with it MANY times. Used it to waterproof wiring connections. Seal leaks, hobo cook stove, homemade shaft packing, and a bunch of other stuff. I've NEVER had ANY reaction to it, at all.

??????????? Maybe I'm indestructible, played with lead and mercury all the time as a kid, too.

Capt Turk

sounds like you are refering to common candle wax;

According to the material safety data sheet, that's really all it is. Paraffin (household wax)

Machineable wax generally contains a wide variety of materials. Paraffin is usually less than half of the content. They also contain other types of waxes and plastics which increase its strength. I am sure there are also proprietary chemicals added to increase strength, improve surface finish, etc. in most commercial products. There is definately a possiblility of some nasty stuff in them.

Carefully watching the temperature can keep the fumes to a minimum, overheating will give off fumes and also become a fire hazard. Definately not the best thing to do in your kitchen.

Assuming it is safe is not a good idea when your life is on the line. Most manufacturers probably do not intend for you to remelt the wax, they want you to buy more! so warnings about this might be rare.

FYI Legos don't come with any warning either and I'm pretty sure that melting them down in your kitchen would do some damage to your respiratory system as well.

I'll never bet my life on someone elses lack of information, I'd suggest others to do the same. If there is a possibility of harm, protect yourself. Be it safety glasses, gloves, lab coat, respirator, parachute, etc. The best way to be safe is to use the safety gear made to kep you safe.

Matt

The above MSDS is for paraffin, not machinable wax.
Here:
http://www.freemansupply.com/MSDS/scanned/Freeman/Machwax_comp.pdf

The ingredients are listed as "proprietary", that enough to scare you?
From the MSDS it appears the most damage is caused from inhalation of fumes generated by thermal degradation ie. overheating. Maybe a double boiler type of apparatus would prevent this. In any case, I would still recommend doing so in a well ventilated area suitable for the purpose.

Here is there specification for the process:
http://www.freemansupply.com/instruction/Reclaiming.pdf

found that here:
http://www.cnczone.com/forums/showthread.php?t=26624

Matt

Hmmm...sounds like I'd buy a cheapie hotplate and do it in the garage with the door open. Or maybe an old electric oven? Or a toaster oven? Again--in the garage with adequate ventilation.

Use a double bolier, like for chocolate.
Or a very low heat.

If the heat is too high, you'll 'cook' the wax and make smoke.
low heat will melt the wax.

CC

Thank you all; I have noticed they updated their webpage to include some info on recycling the wax.

I think the best thing to use would be a Crock Pot set to a low temp in a completely ventilated area. :D

melted wax acts like a solvent does at room temperature, filling the atmosphere with hydrocarbons, which are not good to breathe. You definitely don't want to melt wax in an inadequately ventilated space. Also, it's important to control the temperature precisely. Electrically heated pots are better than melting directly over a stove, but unless your pot has an infinite range control (not just High Medium Low) you're unlikely to get it just right. If it's too low, the wax won't melt, and if it's too high you get a lot of fumes - just before the Towering Inferno kicks in. Really, wax has a flash point; over a certain temperature, it will act like a fuel - think of Sterno on steroids. So if you don't have the ventilation set up, do this outside, with nothing combustible nearby or overhead.

Andrew Werby
www.computersculpture.com