Perry Mick wrote:

OK, what are the facts regarding coolant being flammable?
I tried to ignite some this morning with a bic lighter, no go.
More alarmism?

The vapors of glycol have a fairly low flash point.  I don't think

the fluid

is very flammable.  Flash point is defined as the temperature of the

fluid

in an open vessel when the vapors will ignite if a flame is passed

over the

top of the vessel.  I tried this with pure propylene glycol a while

back

'cause I couldn't believe it myself.  We had a good little weenie

roast

going at a temp well below where we planned to operate (around 200

deg

somewhere...I really don't remember).  That was all fine and good

until the

young machinist who was standing watch with the fire extinguiser

decided to

put it out by shoving the snout of the FE right up to the vessel.

The FE

material (I forget which type) didn't have enough time to vaporize

and was

dumped into the hot glycol as a liquid.  It then vaporized with a

bang and

shot hot glycol all over the shop.  It was not one of my better days.
Luckily the fire was out and noone was hurt (as long as you don't

include

pride)

Jeff Spitzer

Bill Freeman wrote:

Wow!   Sounds a bit "interesting".     Does this happen with ethylene
glycol, too?  Propylene glycol is the non-toxic coolant, which I have
never used, and might not want to.   Seems like another fine addition
to a coolant leak - FIRE !    I had always assumed (and you know what
that means) that coolant, which is half water would be non-flammable.
Sounds like another reason for aircooling, if 50-50 water-ethylene

glycol

mix is flammable, as it sounds like it might be.

Bill
Long EZ builder & pilot
mechanical engineer

I'm not sure about the ethylene flash point but I'd venture to guess it's
about the same.  I'm don't know what effect adding water makes.  Sounds like
a good experiment for somebody (unless the answer can be found through
research)  I've had my fun already.

Jeff Spitzer

 
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