Coolant advice for Integral tank drilling machines

Good Afternoon,

I'm looking for some advice on coolant selection if possible, the company is mainly laser cutting and folding. However the decision was made to expand and set up a drilling and tapping section to go alongside the laser cutting and folding.

We have purchased a geared pillar drill and medium size radial drill both with flood coolant and integral coolant tanks.

I have been tasked with ordering tooling and equipment for the new section, and I'm stuck over what coolant to order for the machines. I have been advised by our health and safety representative to order some fully synthetic coolant, presumably due to it being good at resisting bacterial growth, however after talking to a supplier and some research myself it seems that fully synthetic coolant is not as good as water soluble or semi synthetic coolant at preventing corrosion and that it can be worse for drying out seals on the machines and causing skin irritations.

The machines are unlikely to be used everyday at first, so would this cause a normal water soluble coolant to quickly become a haven for bacteria to grow?

the other question I have is regarding the integral coolant tanks on the machines does anyone know any good methods for cleaning out of the tanks i.e. if overtime chips build up as I believe chips in the tank are also a breeding ground for bacteria.

I think the last time I had to deal with coolant for machining was back in college and the instruction was more on how to mix it and fill up your machine rather than correct selection of coolant.

If anyone has any advice or help it would be greatly appreciated.

Kind regards

The Orange Tapper

Integral coolant tanks are the most evil contraptions ever devised by man. And cleaning them out is nothing but pure punishment- no way around it. To make it worse, many versions have little tiny access doors that force one to use their imagination to create scraping tools on the end of 4' long sticks. Still, getting that far corner to remove the last bit of crud will take hours and try your patience.
Been there, done that way too many times.

Regardless of which coolant you select, tramp oil will be your enemy. Install a skimmer and throw an aquarium pump in the sump to keep the coolant oxygenated and the little bugs unhappy- that's the best you will be able to accomplish.

See if you can have a sheetmetal shop make up some pans, leading out to an external coolant tank.

Hi Dan, thanks for the advice, you are right it does look like it will be a right pain to clean, I've had all the access points off to see what I was working with and it is not great to make things worse the tank is actually split into two parts via a wall with a 1" x 1" hole at the bottom to allow coolant to flow through.

I have seen a little Aerator pump by Abanaki for £20 on MSC so I will buy a couple of those.

as for removal of tramp oil I might try and find some absorbent pads to try before trying to justify paying around £200 for a belt type skimmer.

Doug, thanks for the suggestion I will have a look into this if I cant get anywhere with the built in tank, then I always have that as a option to build and setup up a separate tank and collection system.

If you’re taking the health of your coolant really seriously you need to buy a “ refractometer “. That measures the percentage of oil and water in the mixture.

Regards Tyrone.

Tyrone Shoelaces said:

If you’re taking the health of your coolant really seriously you need to buy a “ refractometer “. That measures the percentage of oil and water in the mixture.

Regards Tyrone.

Click to expand...

Hi Tyrone,

Thanks for the recommendation, I did watch a video from Haas on coolant that suggested the use of these. I'm assuming that this would allow you to correctly top up your tank to maintain the correct ratio of coolant to water.

Orange Tapper said:

Hi Tyrone,

Thanks for the recommendation, I did watch a video from Haas on coolant that suggested the use of these. I'm assuming that this would allow you to correctly top up your tank to maintain the correct ratio of coolant to water.

Click to expand...

That’s the idea. The one I used looked like a monocular. You put a splash of coolant onto the lens and held the refractometer up to the light. You can see a vertical scale with graduations. The coolant shows up as a light horizontal line. You can of course can buy digital versions also. They are very accurate in my experience.

Different types of machining procedures need different mixtures. Most pro shops have a metering valve attached to the drum of neat coolant oil that regulates the amount of oil being added to the flow of water. You can vary the percentages by changing the little nozzles in the valve.

Regards Tyrone.

From the above, it would seem to me that a straight oil coolant/lubricant might be best. Such as Mobilmet or the like.

But one must still clean the coolant tank out from time to time.