If you could only choose one coolant

[Gary Paine]

My new to me Atlas MF horizontal mill has a coolant reservoir inside the column. It has no drain hole and the pump can't suck the last cup or so out of the bottom. The only way to empty it and change coolants is to remove the pump and reach inside with a rag to soak it up and wring the rag out....yuck.
So in a general home use environment, where I will be cutting steel, aluminum, cast iron, and bits of unidentified materials, is it possible to use a single coolant for all. Could it be left in the sump for months, even years without going rancid or bad?

[j king]

I had used cimcool 5 star for several years and never had it stink. I can't find it in a 5 gal now so don't know what to get now. Stuff was great

[lakeside53]

IMO.. no. OK, you could use one of the water based coolants but you will still fight it over time.

Divert the source and return to a 5 gallon bucket, and swap buckets when you need different coolant. Put the pump in a lid of the bucket.

On my lathe it's just not practicable to use the sump pump system - oils from the lube system get into the coolant sump and with water based coolant emulsifies and/or solidifies to a nasty mess. And no place to put an oil skimmer.

[PixMan]

I've had a full synthetic coolant in my lathe since 2006, only adding water and skimming tramp oil (with a hydrophobic pad) once a year and the concentration remains the same. It's "Tri-Cool TC-1", and hard to find now. I put ValCool VP910 (also full synthetic) in my new coolant system for the surface grinder two years ago and it's also as good as new. No signs of any tramp oil in it yet. Both coolant systems get VERY little use, perhaps 5 or 6 times a year at most.

[Jaakko Fagerlund]

As for emptying machines, we have a venturi ejector that we place on a 200 liter drum lid, then attach a hose to the other drum lid hole for sucking up liquids/swarfbits. When you turn on the pressurised air, it pulls a vacuum inside the drum and thus it sucks very good. Cheap and easy to make, calibrating it for maximum suction needs just a vacuum gauge.

Or just buy one, they are not expensive.

[Gary Paine]

Thanks for the info guys. I'll head down to Granger tomorrow and see if I can buy a full synthetic in a gallon container.

As for emptying machines, we have a venturi ejector that we place on a 200 liter drum lid, then attach a hose to the other drum lid hole for sucking up liquids/swarfbits. When you turn on the pressurised air, it pulls a vacuum inside the drum and thus it sucks very good. Cheap and easy to make, calibrating it for maximum suction needs just a vacuum gauge.

Or just buy one, they are not expensive.

Now you've given me another out. The venturi ejector sucker reminded me of a small vacuum pump system I already have. I just need a sufficient sized vacuum receptacle (bell jar) and I can wet vac it all away.

[Toolguy]

I use Hangsterfer's S555 coolant in my bandsaw, CNC mills and surface grinder along with their coolant compatible way lube.
Most times coolant goes bad because way lube gets in it. Most way lube has sulfur and other additives that cause problems with the coolant. You can't keep the way lube out so the next best thing is to make it compatible. Hangstrfer's is biodegradable so it's safe and easy to dispose of if needed. It leaves a waxy or oily coating on the vise and machine table so totally protects against rust.
I have been running this combination since 1999 and never have any problem with smells or anything else. Just add water or coolant to keep the right mix and all is well.

[Forrest Addy]

I never use flood coolant on a low production machine especially a home shop maachine - EXCEPT a band cut off saw. There is absolutely no advantage to flood coolant in the home shop. It's all negative. EXCEPT if your machine is equipped with a full chip and splash containment.

Flood coolant is far too messy and a slipping hazard especially in the usual over-crowded home shop where machine tools, benches, storage is jammed to the point that two foot aisles lead from point to point. Also oil based coolant pose fire hazard if in range of hot work like welding. A soaked box and a spark... (shudder!) That's safety

Coolant systems need regular maintenence. Tater and concentrate top-ups, sump cleaning, regular disposal (EPA disposal inmost cases) of spent or stale coolant. Then there is coolant seeping into mechanisms and sumps there to cause corrosion, stinks, and if neglectedd siezure of working parts. That's maintenence.

There is no "best" coolant. Different materils. operations, applications etc may rule out what you have in the sump. That said, the best all around coolant to my mind is soluable oil. Cheap, buy it anywhere, very effective in most materials especially for drilling, non-allergic, non-toxic (but don't drink it.) OTH is grows stale and may turn into a science project if neglected. Mineral lard citting oil lasts for years and works well in most materials, non allergic, non-toxic. Many water based coolants are nearly univerdsal if the conceentration is optimized but many pose sking sensitivity hazards, and some are quite expensive. No one coolant is completelyt universal, long lasting, environmental friendly, kind to critters if ingested (got pets?), etc. It's a best three out of five kinda thing. WHatever you have in the sump may not be the best choice for the work of the moment. That's specificity.

Therefore I strongly reccommend no flood coolant. I use 1 qt laundry squirt bottles bought in box quantity. I might have on hand 2 quarts of soluable oil, one of heavy black sulpher oil, and one of mineral lard oil. Also I have Tap-Magic, a tuna can of bacon grease, and a couple home brew coolants on hand. When I clean up after a job the coolant I used comes up with chips and mess. No sumps, pumps, hoses, splash, hidden drips, seepage into crevices. That's practical.

Consider coolant on a heavy production machine. Flood coolant gives you 10 to 40% greater production and double to tool life. Flood coolant in a production environment is cost effective and offers a competitive advantage.

A home shop machine tool is usually run to 10% of its production potential has little need of flood coolant. Parts are small; runs are short; materials are varied, idle intervals are long.

YMMV of course but generally speaking don't bother with flood coolant. If you yearn to run coolant because that's what the big dogs do, resist the wanna-be impulse. If you NEED to run flood coolant for practical reasons, that's a whole different story.

[Stern]

I use a spray bottle for my coolant when using the mill (do have a flood setup on the lathe but need to replace the pump). I found using coolant makes the end mills last longer, so even though its messy I use it all the time when milling. I AM going to add a flood system just because my hand hate me when they are asked to squeeze all the time. I put a dam on the mill table top to make floor run-off a non-concern, and like the lathe one I made will also have to flow at the rate I set it to (which goes lower that a drop a second if I want, or a couple of GPM). Maybe its just me, but I find the squirt bottle end up making MORE of a mess (maybe because my aim isnt true LOL). Should make a flood system for the Rigid 300, as squeezing that stupid oil bucket handle is brutal on my already old and misused hands

[boslab]

Get an oil sucker, I use mine for just about all my oil changes, stick the probe in and pump, it's like a Hoover for oil!

http://www.toolstop.co.uk/sealey-tp69-vacuum-oil-fluid-extractor-manual-6.5ltr-p12233?gclid=CMHV29S_gLkCFXMbtAodlkQA6g

Fits down the dipstick hole of cars so saves unscrewing sump plug.
Regards
Mark

[MrFluffy]

I have flood with synthetic soluble oil in water on my mill, it came with all the table drains etc integrated so I filled it with gulf hydrocut synth mix and the required quantity of water and thought nothing of it. I changed the contents of the sump once in 10 years and that was because I was moving workshop (I think I put it back in after too ) . I ran out of hydrocut and switched brands to something called usiov because I can get it locally easy and it doesnt seem to have been upset by mixing the brands etc.

I really like having it for machining stainless because otherwise it work hardens rapidly and I use it when hogging too. When the machine isnt actually cutting I deploy a cunning scheme to cut down on wastage, I turn the pump off and I aim the nozzle carefully.
When I want a different coolant for some reason, I just pick up a spray bottle with it in.
Surface grinder I run the same solution in that too, and its even more useful on that for me. Dry I have problems occasionally but wet I get much nicer finishes and far less airborne dust (though I do have to clean the catch tank and wheelhead housing of black dust drool after a big session).
Lathe has a can with a paint brush on it held on the tailstock with a neodynium magnet out a hard disk, Ive got a pump and am building a tank for that the same but know from experience I'll need a chuck guard to prevent that stripe of coolant right up the wall behind.

[Dr Stan]

I weighed the various pros & cons and settled on old fashioned petroleum based cutting oil cut 50/50 with diesel fuel. No its not perfect, its a comprise, but does well in a variety of materials and I can use it in my lathe, mill, & cut off saw.

When I use my metal cutting blade in my compound miter saw I clamp the work in place so I can use a poly sprayer filled with water. Less messy and reduces the number of hot chips hitting my bare arms.

I've never been a big fan of water based coolants due to their propensity to sour and my personal issue of contact dermatitis from multiple brands.

When I finally get my T&C grinder I plan to get a Cold Spot as it only uses cold air and will combine it with a dust collection system.

[GEP]

Gary
There is a company in Grand Rapids Michigan that makes syntheticc coolant. I fund it for my horizontal cutt off saw because it was the only product that would not freeze at a low temperature because i keep my saw in a unheated area. The company will sell you just 2 gal if you want to try it thats what i did.
I will get you the info a bit later.

[Gary Paine]

I want to thank you all for the input. A lot of good stuff to ponder. Although I have only used coolants and cutting fluids from small squeeze bottles in the home shop, I do see improvement in finish and the cutters appear to last longer when I do. As Forest surmised, though, I was really attracted to the fixed coolant delivery system because it was built into the machine, compact, and not bad looking as coolant systems go. The machine's new stainless steel chip pan, and table and bed castings are all set up to handle a coolant return if it is used. I'm not really sure that I would have called it a coolant FLOOD system as I envisioned using it much more like a coolant DRIP system, but that may have been a semantics thing. I wouldn't be happy if the cutters threw a spray of coolant around, I wouldn't want side shields in my way, and I wouldn't like to see a mess all over my new alkyd enamel and clean cast iron either, so... The cutters on a horizontal mill do not spin anywhere as fast as a lathe, so maybe a steady drip wouldn't be so messy, but I think I'll do some experimenting now before I fill up that reservoir with expensive coolant.
Thanks again,
Gary

[boslab]

I've used a drip feed on my horizontal, I had to make guards, it sprays a bit!, I like the smell but it can ruin clothes, even a small amount sprays, found big diameter acrylic tube lends itself to clamshell guards
Mark