View Full Version : Coolant for Grinding

Paul Alciatore
11-02-2007, 02:22 AM
Coolant is recomended for grinding: I have seen this from multiple sources. And also for running a diamond trueing tool. But what coolant, what type of coolant is best? Water based? Oil based? Or what? Or does it matter? I have seen Tap Magic work wonders when using abrasive; much better surface finish. But this is about my only experience. Perhaps others are better?

11-02-2007, 07:42 AM

For surface or cylindrical grinding, (where wheel loads are light), I like a good water based synthetic coolant. They will give excellent results and are non-allergenic. And they resist rancidity. Dilutions tend to be around 40:1, (water to coolant), so are cheaper than they may appear. Any machine tool supply, i.e. MSC, Enco, WSTool will carry a brand or two.

Water soluble oils will work also. Though I only use them for really big coolant tanks because they are a bit cheaper. But they will tend to go rancid and leave a film on the parts that I don't like. But when you've got an 80gal tank to fill, those pennies can add up.

I don't like straight oils for grinding, They don't carry the heat away as well as water soluble. And you can get that whole fire thing going as well:D .


11-02-2007, 10:26 AM

you can grind dry and get good results, although i see the advantages to coolant.

I was chatting with friend years ago who i think of as a very skilled machinist .....I said something about how i should add coolant, might reduce the amount airborne crap I end up with. he said coolant's no picnic either, that if he's been grinding that day, his wife can smell the coolant on his breath. :eek: makes sense that the wheel surface speed would act as an atomizer whereas with machining it just sloshes around. If i was picking a coolant I'd be trying to figure out what was the most benign to put in ones lungs.

Paul Alciatore
11-03-2007, 11:06 PM
Sounds like water based over oil based and the choice is more based on the side effects than anything about the grinding process.

11-04-2007, 10:35 AM
mines far from a professional opinion Paul, just a tidbit i threw out.....was surprised that there wasn't more forthcoming on this...

11-04-2007, 10:55 AM
mines far from a professional opinion Paul, just a tidbit i threw out.....was surprised that there wasn't more forthcoming on this...I use a synthetic that mixes with water, I cant remember exactly what it is though, I wouldn't overthink it though just look in MSC or one of the metalworking catalogs and get one made for grinding.

You can dry grind with either a cold air gun with really good results. Or you can just grind dry with no air, you just can't be as aggressive with your cuts and you need to pay attention to how hot the part is.

As for breathing the stuff, I usually wear one of theose cheap face mask and I open the shop doors and point a fan in my direction to try and blow the stuff away, if you dont do that you will get some black boogers and I am sure that isnt good for the lungs

11-04-2007, 11:37 AM
I generate three to four pounds of carbide sludge every couple weeks surfacing pelletizer dies,I use water soulable coolant same stuff I put in the lathes and mills,but at a lower concentration like 40:1.Just enough oil to keep the machine from rusting.

Grinding you need enough coolant not only to keep the wheel cool,but also to keep the part being ground from thermal cycling.If your going to be hogging off large amounts of material a flood is needed if your just tool grinding then a steady rate of drops will be enough.

The truing tool you really don't need to buy,a piece of old AOX wheel mounted ridgid will dress the wheel round,it just takes a little longer.You will need another piece of AOX later to clean the wheel and bring fresh diamonds to the surface.