Syn-kool Vytron-N on aluminum

[cn00728]

Hello,

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.
Thank you,
Alex

[coolantman]

Alex,

Unfortunately you aren't the first person that has had problems with synthetic coolants staining aluminum.

In order for synthetics to get such great sump life, the alkalinity levels need to be a bit higher than other coolants to keep bacteria growth from showing up. Your staining is most likely coming from the alkalinity level of the coolant. I'm guessing your pH is around a 9 or 10. Since aluminum is a softer metal, it has a hard time withstanding this high pH level.

I can't tell much about Syn Kool just by looking at the MSDS, but the phrase "limited use on aluminum" is a common term used by many synthetic coolant companies just for that reason, some of them stain aluminum.

All synthetic coolants don't have this problem. We run synthetic in many machine shops that have never had that problem with aliminum. It just depends on the alkalinity level and the amount of caustic in the product.

I hope this helps Alex, please feel free to contact me if you have any questions or concerns.

-Jonathan Ballard
EnviroServe Chemicals, Inc.
(910) 892-1791
www.enviroservechemicals.com