I have a Haas MM that I am wanting to change the coolant on, as I still have the original Syn-kool coolant in there for TWO! years now. This is hobby level use, the mill usually sits idle for up to a month regularly, which is hell for the coolant but it has stood the test this whole time. I never check levels either, just kept adding water to keep the tank full. Nuts huh?
So that's my situation. I was cutting some 7075 the other day and had seen that staining occurred the next day I looked at them. Is this common for Syn-kool, or are my levels that far out of whack? I question the Syn-kool as it's listed as for ferrous metal use. They state "limited use on aluminum" What does that really mean?
Some research has turned up that Syn-kool, is actually Vytron-N from ITW's Rustlick line. Add to that, if you use Vytron-N, just buy Syn-kool as it's a little cheaper.
I had been so pleased with the sump performance of this Rustlick product, that I wish to stay with their lineup. AND, not a speck of paint has been eaten away on my mill. However, looking at the other synthetic coolants they offer all state that use on aluminum is "limited". Is this limited use due to the staining? I can't have that.
Is staining to be expected of any synthetic coolant? Just to clarify staining, the effects I have seen is that it looks like short little lines in the grain, sort of like filliform corrosion. On one part it was where I grabbed the part, so you could see my hand print on it.
I'll also have to get a ph tester, and keep things at 5.