# Coolant - Yea or nay



## Blogwitch (Jul 27, 2009)

The only DRO system that I have seen that is completely waterproof and can in fact be used underwater, are the latest Newall read heads. A set of 3 would most probably set you back a couple of grand. But they are rather good.

The normal glass read heads can be bought with very good covers for them. So if they are mounted in the correct positions (NOT upside down or the open side facing the coolant flow), you don't really have to worry about swarf or moisture penetration, they do a fairly good job of keeping it all out, but I wouldn't guarantee them keeping out a direct blast from a flood coolant nozzle.

Is coolant required?

In my opinion, yes. 
Not only will your tooling stay sharper for longer, they will last a lot longer as well. You will also find that surface finishes improve dramatically if you can keep the tool cool and get a bit of lube on there as well. Don't use full flood coolant, that is for the big boys, instead, using a small dribble will keep the tooling very happy.

If you have air in your shop, then you might consider a spray lube system, they use a combination of air to keep the tooling cool and a very fine mist of coolant oil for lubrication. You can adjust these to very low consumption rates, so that you could just have a total loss system, and do a quick wipe up at the end of the machining session, rather than having coolant oil dripping everywhere if you used a flood coolant system.

http://littlemachineshop.com/products/product_view.php?ProductID=2725&category=

I hope this answers your questions.

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## rtp_burnsville (Jul 29, 2009)

I have been looking at the micro-drop systems from companies such as Trico.  Everything I have read gives them good reviews with results similar to flood systems less the mess. 

I was about to order one when I discovered some plans to build a similar system for not many $'s. I am currently collecting the parts and plan to give it a try. The main difference between a fog system and the micro-drop is that the later uses a pressurized coolant to produce drops which produces no coolant fog throughout the shop. It's a very interesting concept....

Robert


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## Tin Falcon (Jul 29, 2009)

well tell us where we can get the plans I am sure others are interested. I am !!
Tin


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## hammers-n-nails (Jul 29, 2009)

well im not an expert but id have to agree with blogwitch exept for the part about the coolant fogger, i have a flood system and a fogger on my machine, the fogger is fine when your side milling but it seems like i get into alot of situations when it just doesn work that good, for example when i was making the frame trusses for the engine you see in the picture i was cutting a slot with 3/8 endmill 3/4 deep and i just turn on the pump and the bit is totaly submerged and stayed cool with shavings packing in all around it. but blogwitch is right flood systems do make a mess, on the mill, floor, and you. so you really could go either way depending on exactally what your doing i just think the flood is alo more versatile. it seems to me by talking to a few machinists that the best type of system to use is largly a matter of opinion. also asblogwitch already said keeping coolant out of the dro isnt a problem with the gaurds.


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## Speedy (Jul 29, 2009)

rtp_burnsville  said:
			
		

> I have been looking at the micro-drop systems from companies such as Trico. Everything I have read gives them good reviews with results similar to flood systems less the mess.
> 
> I was about to order one when I discovered some plans to build a similar system for not many $'s. I am currently collecting the parts and plan to give it a try. The main difference between a fog system and the micro-drop is that the later uses a pressurized coolant to produce drops which produces no coolant fog throughout the shop. It's a very interesting concept....
> 
> Robert


please share!

I was thinking of Fog, but im sure my parents wouldnt like chemicals floating in the house !!!!


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## shred (Jul 30, 2009)

I've got one of the Spra-Kool midget units, but rarely use it. On my little CNC machine I gave up and ran flood, which works great but makes a bit of a mess even with the shower-curtain enclosure I made for it. On the manual machines I don't usually mess with it except for special situations where a squirt or brush of cutting fluid won't do. I've heard the kind with separately adjustable air and liquid are easier to tune, but not seen one in person. If the Bogster says it's a good idea though, I'll have to mess with it some more. He's rarely off on things like this.


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## JimM (Jul 30, 2009)

Thanks for the replies, looks like it's a thumbs up to coolant but not to the flood type if it can be avoided

Done a quick bit of searching and I think the plans that Robert is referring to are on the Metalworking.com site


http://www.metalworking.com/dropbox/_2002_retired_files/Zero_Fog_Mister.JPG
http://www.metalworking.com/dropbox/_2002_retired_files/Zero_Fog_mister.pdf
http://www.metalworking.com/dropbox/_2002_retired_files/Zero_Fog_Mister.txt
http://www.metalworking.com/dropbox/_2002_retired_files/Zero_Fog_Mister.dwg

Cheers

Jim


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## rake60 (Jul 30, 2009)

One more thing to consider is the tooling being used.

HSS tools will work fine dry, flooded or fogged.

Carbide tools are happy with either dry or flooded conditions.
They will not do well with a fog or mist system. An inconsistent
coolant allows the possibility of thermal shock. 
Thermal shock will cause a carbide tool or insert to shatter.

Rick


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## rtp_burnsville (Jul 30, 2009)

Thanks Jim for posting the main links to the build your own micro-drop system.... FWIW, There is a difference between micro-drop and general fog systems which many assume to be the same but they are not.... I would be interested if any others build such a system. Hopefully my schedule will free a bit so I can get back to assembling my parts and some initial testing.

Trico (MD1200) and Acculube are two of the large manufactures of micro-drop systems that I am aware of. Both are fairly expensive in the $700-$1200 range for a two nozzle system. 

As several have mentioned a flood system or a fog system just would not work in my shop so this may be the solution. New ideas catch on slowly at times, and this just may be one of them.


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## reggie98 (Jul 31, 2009)

Flood coolant, for a hobby or part time shop, no. Coolant does go bad, stinks and _supposedly_ can grow some dangerous microbes. Tools will stay sharp longer if properly cooled. If you have a large compressed air supply, consider a cold air gun, plans exist on the 'net to build your own. Use a hand spray bottle and clean up after your done or get one of those small pump-up sprayers. Use it as your pressurized coolant tank, just add a delivery system using tubing, nozzle and holder. Or buy something off the shelf, like a BIJUR.


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## CrewCab (Jul 31, 2009)

OK guys, I've got a flood coolant system and it's a Royal PITA ................. cos it goes everywhere ??? ........... was thinking about a "Mist" system but now it appears that has severe disadvantages for a home shop too ............ 

So ............. I'm watching with interest 8) .............. thanks to everyone for your input so far ....


....... Oh, my opinion, my Engineering experience stems from school in the 60's ............ coolant was "always there", it was part of the machining process, to think of not using coolant just wasn't an option  ............. so ............. I prefer to use coolant 

CC


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## Maryak (Jul 31, 2009)

Guys,

To quote from a publication "Machine Tools, Metals and Cutting Fluids" by British Petroleum

A cutting fluid has two primary functions:

Cooling - To conduct away from the cutting area the heat that is inevitably generated and in so doing, to prolong tool life.

Lubricating - To reduce the friction between chip and tool face - in order to reduce heat generation, tool forces and power consumption and to improve tool life and surface finish.

IMHO all of the above are of great interest in a production environment but are they so terribly important in a hobby environment. ???

For myself the achievement of a good surface finish on a finished part is important, the rest tend to fall by the wayside.

Our machinery for the most part falls well short of what is found in a production machine shop and lacks the shielding etc. required to confine/utilise the benefits of a full on coolant system.

Others have raised the points about the mess and the possibilities of bacterial growth and subsequent skin lesions. I don't think breathing in the vapours from an unconfined mist system would be all that flash either.

Considering all this, a simple paint brush or a spray bottle are my solutions where coolant is needed.

Hope this helps ???

Best Regards
Bob


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## websterz (Jul 31, 2009)

I use the windshield washer tank and pump off of my old van as a coolant system. I wired it to a 12 volt wall wart and put in an in line switch so I can squirt in a drop of coolant now and then as I cut. The coolant nozzle is a blunt hypodermic needle that I salvaged from an old inkjet refill kit. I was a nice tight fit in the end of the hose, and I secured it with a nylon cable tie. The nozzle is mounted on a Mighty Mag base so I can position it wherever needed. Initially I built it just to use when parting on my 7x12 but it works so well, and is portable, so it spends a good bit of time on the mill now.


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## shred (Jul 31, 2009)

FWIW, I dropped a little fishtank bubbler into my flood coolant bucket on an on-10-minutes, off 30 timer and it stays stink-free for many months of between uses.


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## deere_x475guy (Jul 31, 2009)

Shred that's a great idea, the coolant in my bandsaw goes bad long before I have used it up. Where did you get a time that works like that?


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## shred (Aug 1, 2009)

I got a light timer-- the kind that has a wheel with a whole lot of segments-- push down or in the segments for when you want things on or off, the wheel slowly rolls around, turning the lights on or off on schedule. I set every third segment to 'on', the rest to 'off'. The idea is to keep the anaerobic bugs from growing by piping a little oxygen in every so often and also breaking up the surface oil layer some. I'm guessing the frequency and duration are nothing like critical, but if I run it all the time, the coolant evaporates faster.


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## Blogwitch (Aug 1, 2009)

With reference to your coolant 'going off'.

A little bit of web searching should get you the latest type of coolants. You shouldn't have to put up with fungus and sour smells any more.

I am lucky in that a friend gets me a pint bottle every now and again, just to top mine up.

Before I did my workshop rebuild, the coolant that was in the tanks on my old machines were at least a couple of years old, and in fact, the coolant went with the machines when they were sold. Not one sign of fungus or that sour smell, just like the day I mixed it.

It might cost a little more, but it works out cheaper in the long run.

I have also found with my new machines, I don't get any of the staining or 'sticky' feeling you get with older types of coolant. Just a quick wipe down, and then forget about it.

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## David Morrow (Aug 3, 2009)

I built my own flood coolant system for my enlarged Sherline CNC mill and am very happy with it. I get a bit of spray beyond the shields when using end mills larger than 3/16" but I just need to make the shields an inch or so taller. I wouldn't live without it.

http://www.ldrider.ca/cnc/coolant/coolant.htm


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## deere_x475guy (Aug 11, 2009)

shred  said:
			
		

> I got a light timer-- the kind that has a wheel with a whole lot of segments-- push down or in the segments for when you want things on or off, the wheel slowly rolls around, turning the lights on or off on schedule. I set every third segment to 'on', the rest to 'off'. The idea is to keep the anaerobic bugs from growing by piping a little oxygen in every so often and also breaking up the surface oil layer some. I'm guessing the frequency and duration are nothing like critical, but if I run it all the time, the coolant evaporates faster.
> 
> Hmmm..seems to me I have one of those I forgot about. I need to check around and see if I can find it. Thanks for getting back to me.


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