[i_am_fubar]

So I just purchased a 1.5kW water cooled spindle motor for my self build mill. My question relates to the 'water' part.

I live in a hard water area, and really don't want to risk furring up the spindle with calcium deposits. I could use battery water as it is pure, but I was also wondering if I could use a thin oil as it would guarantee no corrosion or deposits.

Is this a viable idea?

Also, I have an old AC radiator to act as a heat exchanger, but what could I use to pump the coolant? would some pumps be adverse to oil?

Sam.

[coolantman]

Sam,

Sounds like you know your water content pretty well.

A synthetic coolant will provide more than enough corrosion protection while at the same time keeping your spindle much cooler compared to an oil. Synthetics have zero oil and in most cases can be discarded like most waste water.

With regards to a coolant pump, I have read several posts from members who make coolant pumps with household items.

Could someone give Sam some ideas on how to pump his coolant?

-Coolantman

EnviroServe Chemicals, Inc.
(910) 818-7412
www.enviroservechemicals.com

[i_am_fubar]

Accumulated hours spend de-scaling kettles, pans, pipes, toilets and cold water tanks kinda gives me an idea about how hard the water is in my area.

I like this synthetic coolant. Don't suppose you know of a supplier?

And I was thinking a washing machine pump at the lower price band, and a central heating pump at the higher. Will listen to other ideas though.

Sam.

[Lucanus]

I live in a hard water area, and really don't want to risk furring up the spindle with calcium deposits. I could use battery water as it is pure, but I was also wondering if I could use a thin oil as it would guarantee no corrosion or deposits.

Sam.

Hi,

I might be able to shed some light on your question...

The same issue has been up for discussion in numerous threads on computerforums, or rather when it comes to watercooling computers.
I've been running all my boxes with diffrent watercooling systems for the past 8 years, all filled with regular tap-water.

The general idea that hard water will aid in the buildup on calcium deposits is a viable statement, just look at any 5+ year old coffeemaker.

Time for some statistics:

Simply put, water hardness is meassured by the sum of diffrent types of natural salts (mainly calcium and magnesium ions) compared to the equivalent amount of calcium carbonate (CaCO3) in milligrams per liter.
We have the germans to thank for the system of meassuring water hardness.
The scale looks like this: 1 dH = 20 mg CaCO3

Regardless of where you live in the world, the following applys:

Mg/l CaCO3

0-50 = soft
50-100 = mediumsoft
100-150 = somewhat hard
150-200 = medium hard
over 200 = hard
over 300 = very hard.

Lets do some maths and make an ass out of ourselfs for assuming the following worst case scenario:

1. We live in a limestone mine and have a hard water (200 mg CaCO3/liter.
2. We have a closed loop cooling with 10 liters of water in the system when filled up.
3. We do a complete drain/refill of the system once a month.
4. 10% of the available minerals in the water gets deposited before each refill. (this is probably a gross overestimate)

Based on this we will add about 2,4 grams of minerals deposits in the system over a 1 year period. The 2,4 grams are evenly distributed on the inside of tank, pump, tubing and so on.
So, unless you built your house in the middle of a limestone mine and don't feed the cooling-system with a continous supply of mains water - you have nothing to worry about.

But it doesn't cost much to be on the safe side - fill up the system with de-mineralized water and buy yourself free from any potential damage caused by cutting a $10 corner

This was my first post on cnczone, sorry for threadjacking... Hi everbody!

/Luc

[rowbare]

Have you seen this thread? http://www.cnczone.com/forums/showthread.php?t=78742
Watch his video, it shows his cooling setup.