mist or flood?

[Vinny]

For a surface grinder, what do I want to do, mist or flood cooling? If flood cooling, what volume?

[Sunset Machine]

Mine's a flattened nozzle from 1/4 copper tube, trying to achieve a fan spray close to the point of contact. Flood to wash away the crud. I prefer grinding dry but it puts gritty dust into the air.

[Vinny]

Never thought of using copper tube. I was going to make one out of some hex brass I have. That's much easier! The pump won't be here till next week anyway and I can save that brass for better things.

Thanks!!

[TomG]

I prefer to grind dry as well. It's a lot less hassle to hook up a dust collector than deal with the mess that coolant makes.

Tom

[Sunset Machine]

One thing that occurred to me. The last time I ground something it turned a little brown, my thought was "wrong wheel" but perhaps I should have turned on the coolant. Effectively turning the one wheel into two.

[TomG]

I've worked in a number of grinding shops almost none of them used coolant on the surface grinders. If you are generating enough heat to turn the part brown, there are a number of things that can be done to reduce it. Moving to a softer, more friable wheel will help, as will decreasing the depth of cut and increasing the feed rate. A lot of side movement of the wheel helps as well, as in 3/4" overlap with a 1" wheel (light cuts of course). Quickly covering the entire surface of the part means more heat in the chips and less in the part.

Tom