Re: [CAD_CAM_EDM_DRO] cheap edm tap buster?

Mark Vaughan wrote:

>I note here Jon had problems finding a suitable fluid.
>
>In the wire machines we use deionised water, which is deionised by pumping
>it through resin after it comes out of the filters.
>
>
>
>But on the EDM sinkers we use paraffin, and a fire extinguisher just in
>case.
>
>Paraffin is quite cheap, and readily available. I have never seen a machine
>go up in smoke, but if you play with this I would suggest to be very
>cautious.
>
>
>

Because this thing has voltage on the electrode essentially all the
time, it needs very
clean water or it will foam like crazy with electrolysis. I couldn't
get clean enough
water, but then I didn't try real hard, either.

The stuff I was using was some sort of hydrocarbon, but either had a
fire suppressant
in it, or just had a really low vapor pressure. I did get one "puff" of
flame one time
when the fluid level ran low, although I had sparks ejected through the
fluid all the
time. So, I would be real cautious with flammable solvents.

The British term parrafin is something close to the US varsol, kerosene,
etc. A low-evaporation
paint thinner might be good.

Jon