What coolant for water cooled HY spindle?

[Ziggy]

Hello...

I am finally getting ready to fire up my machine. What I thought was going to be simple has led me down a rabbit hole of blind alleys, horror stories and confusion.

I have a cheap Chinese HY spindle. I assume the water jacket is aluminum. I have no other metal in the system and I am using a Rattmotor pond pump with 1/4 ID lines. My system is a hobbyist Onefinity CNC.

My garage will get below freezing but I plan on blowing out the lines after use.

Just for testing I have been using distilled water.

I was considering adding a biocide or some type of pet safe antifreeze. Some people say any antifreeze safe for aluminum should be OK. Others say that this will kill the pump. Some say that most biocides will cause corrosion in aluminum. Some people say I should only use the $150 a gallon stuff.

Since I don't have dissimilar metals in my "loop" I would think that galvanic corrosion would be minimized... but at this point I am flummoxed with information. Distilled water is cheap. Just change it often?

Everyone here knows more than I do and I have never been led wrong.

So does anyone have any suggestions?

[ShawnM]

Back when I used to run water cooled spindles I ran plain old tap water with just a little antifreeze in it and never had any issues with the spindle. I'm sure you'll get several answers to this question. The antifreeze also added the orange color to the water so it was easy to see if it was actually flowing to the spindle.

[Ziggy]

Thanks! Maybe I am overthinking this.... as usual.

I appreciate the response!

[tblough]

I'd bet you could run any of the antifreeze solutions available at the local computer outlet for watercooled PCs.

[riggsp]

Everyone I know that has a liquid cooled spindle, uses a mix of RV antifreeze and water...and they change it a couple times a year.

[Gary Campbell]

I've always used a racing coolant in the ones I have sold. The coolant promotes better cooling by making the water "wetter" and even more importantly, it provides protection against dissimilar metals causing electrolysis. Most of these systems have an iron water jacket, aluminum, brass, and stainless parts... a battery in the making

[ShawnM]

I've always used a racing coolant in the ones I have sold. The coolant promotes better cooling by making the water "wetter" and even more importantly, it provides protection against dissimilar metals causing electrolysis. Most of these systems have an iron water jacket, aluminum, brass, and stainless parts... a battery in the making

This is why I will only use air cooled spindles now.

[Ziggy]

Thanks for all of the replies!

I have read of others using RV Antifreeze. I can get that locally.

What racing coolant? Is this something that is readily available at O'Reillys or is it something that most people have to order?

Also, I wrote to the Manufacturer and asked which coolant they recommended and the composition of the water jacket. This was their reply"

Ordinary water can be used as a coolant
The water outlet of the main shaft is generally stainless steel, and the stainless steel material will be more stable, and prevent the formation of scale in the pipe, and maintain the cleanliness and health of the water pipe.Thanks

[Gary Campbell]

I used to buy it at a local auto parts store. I asked for the best one for mixed metal systems

[Ziggy]

Thanks! Do you remember a brand name?