[sanddrag]

I've been running Trim C350 synthetic in my Haas Mini Mill for the past several months and it'd a really nice coolant, but I'm experiencing some notable rusting issues. I have mild rusting on the tapers of certain tool holders and considerable rusting in areas of the table and on the vises. It's starting to worry me, so I'm posting here. The coolant is at 5.25% on a Brix refractometer which by my interpretation of the spec sheet seems right where it should be. Is it a cleanup procedure issue? Is it a coolant separation/mixing issue? Is it a water supply issue? What is the cause, and what is the fix? The machine is only a few months old.

Thanks.

[fizzissist]

What's the Brix correction factor for that coolant? If it's 1x, 5% may be low. We run E206 at around 10% and the only rusting is between the vise and the table if left for a long period. We switch out vises like you change socks, so not a problem here.... But after a few weeks things are stinky when you pull it.
Pretty common issue, so I wouldn't fret. The tool holders though... That shouldn't be.
I'd recommend a spindle weenie and wiping down the tapers on a regular basis so there's the slightest coating of oil on them.

We've run one of their other synthetics in the Haas SL20 (don't remember which off the top of my head) and no rusting whatsoever... I'll try and remember to check which one today. I keep it at about 10% too.

You're probably using tap water? Long term, as the water evaporates and you replenish, there's a build up of minerals. We got a reverse osmosis set up for our coolant water and things have gotten better. The coffee quality is better too.

Assuming too that you're adding coolant to the water when mixing, not water to coolant.. ?

Initially, my take is that you just need to up the concentration a little, even if the application says that you're fine at that ratio. I find that with the E206 things are pretty stable at 8-12%.

[sanddrag]

Correction factor of 1.75

[Geof]

Yes bump your concentration up to around 10%.

[fizzissist]

If you're at 9+% now, push it up to at least 12-15% and see what happens. Also, don't be shy about calling tech support... They're actually pretty cordial.
They even took a sample from me and ran it when I was having some unusual problems at no charge.

[fizzissist]

I checked, the lathe is using Trim 585XT semi-synthetic. Haven't had any real rust issues even with the machine sitting for long periods.

[mactec54]

sanddrag

This is a normal problem you get with most full synthetic cutting fluids, change it before it destroys your machine/tooling, yes they work good but rust everything & there is no way to correct it, just change it, to a good semi-synthetic something that works great is Ultracut 380R, but there are other good semi-synthetic cutting fluid as well

[taffmawr]

Is your mini mill using grease central lube with grease supplied by Haas?

[mactec54]

I've been running Trim C350 synthetic in my Haas Mini Mill

Get a semi-synthetic cutting oil, this synthetic coolant will destroy your machine, almost all synthetic cutting fluids will do this (Rust everything), I use Ultracut380R this is a Rustlick product, It is a great coolant/cutting oil, your rust problem will go away with this coolant

You can not use any tool holders with rust on them, they will damage your spindle

This is a old thread taffmawr

[mactec54]

Is your mini mill using grease central lube with grease supplied by Haas?

This is a old thread, But the Haas MinMill has oil for lubrication, not Grease, this is not the part that he had a rusting problem with

[sanddrag]

sanddrag

This is a normal problem you get with most full synthetic cutting fluids, change it before it destroys your machine/tooling, yes they work good but rust everything & there is no way to correct it, just change it, to a good semi-synthetic something that works great is Ultracut 380R, but there are other good semi-synthetic cutting fluid as well

I haven't heard this before. What is the reason you say that most full synthetics rust everything? From the HAAS Mill Operator's Manual, "Machine coolant must be water-soluble, synthetic oil based or synthetic based coolant/lubricant." So does that mean synthetic or semi-synthetic?

I'm wondering if it could by my water. It may be hard water, and I don't have a source of filtered or DI water.

[mactec54]

sanddray

You can use what every you like, this is up to you, because you have rusting then it's not for you, If that is how it is written in the manual then it is incorrect, (synthetic oil based) this should be written semi-synthetic oil based

Full synthetic, is not oil based in any way, so if it is written like that it is in correct

It has nothing to do with your water, all coolant/ cutting fluids are tested with tap water, as this is what most people use, I even tried DI water with more than one brand of synthetic coolant, with not change, just more of the same RUST

It's like I said if you want to destroy your new machine keep on using what you are

Here is a snip of what synthetic is all about, the first part of this tells you why you have the rusting (Synthetic fluids contain no petroleum or mineral oil)

Synthetic fluids contain no petroleum or mineral oil. They were introduced in the late 1950's and generally consist of chemical lubricants and rust inhibitors dissolved in water. Like soluble oils, synthetics are provided as a concentrate, which is mixed with water to form the metalworking fluid. These fluids are designed for high cooling capacity, lubricity, corrosion prevention, and easy maintenance. Due to their higher cooling capacity, synthetics tend to be preferred for high‑heat, high‑velocity turning operations such as surface grinding. They are also desirable when clarity or low foam characteristics are required. Heavy‑duty synthetics, introduced during the last few years, are now capable of handling most machining operations.

Synthetic fluids can be further classified as simple, complex or emulsifiable synthetics based on their composition. Simple synthetic concentrates (also referred to as true solutions) are primarily used for light duty grinding operations. Complex synthetics contain synthetic lubricants and may be used for moderate to heavy duty machining operations. Machining may also be performed at higher speeds and feeds when using complex synthetics. Both simple and complex synthetics form transparent solutions when mixed in a coolant sump, allowing machine operators to see the work piece.

Emulsifiable synthetics contain additional compounds to create lubrication properties similar to soluble oils, allowing these fluids to double as a lubricant and coolant during heavy‑duty machining applications. Due to their wettability, good cooling and lubricity, emulsifiable synthetics are capable of handling heavy‑duty grinding and cutting operations on tough, difficult to machine and high temperature alloys. The appearance of emulsifiable synthetic fluids ranges from translucent to opaque.

Chemical agents found in most synthetic fluids include:Amines and nitrites for rust preventionNitrates for nitrite stabilizationPhosphates and borates for water softeningSoaps and wetting agents for lubricationPhosphorus, chlorine, and sulfur compounds for chemical lubricationGlycols to act as blending agentsBiocides to control bacterial growth.