Surface grinding coolant choices

I have had a Harig 612 grinder now for about 3 years and with the help of experts on this and other forums, and the utube community I have learned a lot. Up until now I have been grinding dry and had good success and nice finishes using the proper grinding wheels and taking my time and not heating up the part. Now I want to make some tool room stones like the ones Robin Renzetti has made and I need to reconfigure my grinder for flood coolant. I don't see any problems making a flood coolant system but I would like some advice as to what type of coolant is best. I am a retired home hobbyist and I probably don't grind more that 4-5 times a month. I would like to use a water soluble type that is stable for the light use. Most of the ones I've seen are a milky white. I am pretty fussy about keeping my shop and machine clean so I hope this coolant isn't difficult to cleanup?
Thanks for any advice

skipd1

I've been using McMaster Carr # 1216K15 synthetic for several years and have been happy. No bad sump problems. Infrequent use of my grinder ,too. Worked good on grinding the Robin Renzetti type stones.

I can't advise you on what brand of coolant to use but the white " milky " type of coolant went out years ago in my experience. We used " SARELF " which was almost see through, especially when mixed down for grinding. I think we used 3.5% coolant instead of the usual 5% for milling, drilling turning etc.

To get the right mix you really need a " Refractometer ". This will give you an exact reading as to the concentration of neat coolant to water. They aren't that expense to buy and well worth it. It takes the guess work out of mixing coolant.

Regards Tyrone.

We use houghton 767. With limited usage you are going to want to use a full synthetic coolant. A trick you can do is put a small airline to your sump and allow it to bubble to break the surface and aerate the coolant to help it last longer.

Every couple days it would not hurt to turn your pump on and let the coolant cycle for 10 mins.

Nothing wrong with the milky white ( soluble oil) coolant. Go to WalMart and for $10 bucks buy a fish tank aerator pump with a small bubble stone and run it for 5 minutes a week and no odour or excessive bacteria growth. Synthetics are cool but not an absolute must.

Thanks everyone for the great input.

skipd1