# Lathe coolants?



## Larry42 (Jun 30, 2018)

I've been using a heavy cutting oil on steel. It makes a hell of a mess and the work (4130) gets pretty hot, quickly. My lathe has a coolant pump system but I've never used it. Guys have talked about the fluid growing stuff and it's short life. I want to give it a try. I'm asking for recommendations. I usually do all roughing with carbide inserts and switch to HSS tools for the finish. As usual for a home shop, I also use aluminum quite a lot also.


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## 4ssss (Jun 30, 2018)

I use Kool Rite 2290.  Doesn't stink, get rancid or rust the metal.  Just mix it a little more than what they call for.


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## Ed ke6bnl (Jun 30, 2018)

first I am no pro but on certain items I use a mister synthetic coolant and the part stays cool and does not get hot. I do not use it all the time and there is a small pan in the chip tray that catches the small amout of liquid that my form.


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## P. Waller (Jun 30, 2018)

I work in a shop with 5 lathes and 7 mills and we go through a 55 gallon drum of soluble oil every 8 months or so, mostly with the NC lathes and VMCs, they have used Zurnoil Aquasol for years, be aware that if a machine sits idle for months at a time most any coolant will go off.

http://www.zurnoil.com/metalworking-coolants/


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## off center (Jun 30, 2018)

I use a product called  Oakflow synthetic .  It seems to work well and if you keep the oil out of it the product doesn:t go bad                                                Gary


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## Glenn Goodlett (Jun 30, 2018)

I use Mobilcut 100 (soluble oil) with a Tormach floating tramp oil collection pillow. I change the coolant and pillow every year for good measure and try to circulate the system every week. Only use distilled water when adding coolant and never had any problems. As a home gamer I run it at 10%.


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## jbolt (Jun 30, 2018)

+1 on the koolrite 2290. Best water based coolant for home use I have found. I have been running that in my cnc mill for three years and the lathe for two. The water will evaporate before it goes bad. 

Sent from my SM-G955U using Tapatalk


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## Larry42 (Jul 1, 2018)

Thanks for the help. There is a Mobil distributor close by. I think I'll try their product.


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## Bob Korves (Jul 1, 2018)

My home shop 13x40 lathe came with flood coolant.  It has never been used and there is only dust in the tank.  That is because of the mess, the smell, and the increased cleanup time to deal with it.  Don't get me wrong, flood coolant works very well.  I, and many others, just do not like to deal with the mess that comes with it.  Instead, I use cutting oils and fluids, Anchorlube, and synthetic mist coolant on my machines.  For a hobbyist, at least in my case, flood coolant just does not make sense.  I have no production schedule that I need to meet...


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## Video_man (Jul 1, 2018)

About your carbide inserts --- I've been told a number of times that coolants and carbide don't mix.  Apparently the repeated heating/cooling as they work causes the carbide to crack or break down.  Something to consider, maybe....


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## Bob Korves (Jul 1, 2018)

If carbide inserts are continuously flooded, then there is no issue.  If a very hot insert is then flooded, it can crack from the heat/cooling stresses.  I am not sure if this is a common problem.


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## Larry42 (Jul 2, 2018)

Video_man said:


> About your carbide inserts --- I've been told a number of times that coolants and carbide don't mix.  Apparently the repeated heating/cooling as they work causes the carbide to crack or break down.  Something to consider, maybe....


Whoever told you that carbide and coolants don't mix obviously didn't know what they were talking about. Now if they run the tool until it is really hot, then turn on the coolant, Yup could be a problem. But who the he!! would do that? My shop is in an Industrial area and I have been in many of the production/job shops. They all run coolant, even on the few manual machines that are still around.


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## MrWhoopee (Jul 2, 2018)

Since you don't need coolant regularly, I would suggest a mist system. I'm not familiar with any coolants that will not go rancid over time, particularly if they are not circulated (oxygenated) regularly. Keeping a coolant system clean and functioning is enough of a pain when you DO need it. I don't miss coming home smelling of rancid coolant.


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## aliva (Jul 5, 2018)

I use Castrol Syntilo. It doesn't smell, doesen't built up bacteria, no smoke, Mixes 40:1 with water and its clear, so you can see what your doing.
But coolants are like tooth paste, everyone has a favorite.


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## mksj (Jul 5, 2018)

Another vote vote for koolrite 2290, per Jbolt's comments the water will dry up before it goes bad. Use it in my horizontal bandsaw with flood coolant and it works very well, and I get minimal rust. You need to be on the upper end of the dilution they recommend. Previously used Kool Mist 77 and it neither held up for long in the sump tank, and I had a lot more issues with rusting.


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## P. Waller (Jul 5, 2018)

Larry42 said:


> Whoever told you that carbide and coolants don't mix obviously didn't know what they were talking about. Now if they run the tool until it is really hot, then turn on the coolant, Yup could be a problem. But who the he!! would do that? My shop is in an Industrial area and I have been in many of the production/job shops. They all run coolant, even on the few manual machines that are still around.


What he said

While insufficient coolant or coolant that is blocked by the chip may cause a temperature gradient across the insert this is unlikely in a hobby shop setting. When you watch ytube videos of lathe demonstrations they are using no coolant because it would be nearly impossible to see the work because of the amount that would be used, gallons per minute.
Like so, parting is difficult without good flow.  




The only time that I do not use coolant is when hard turning and these tools are not carbide but CBN. I use coolant on PVC, Delrin, UHMWPE, aluminum and free machining brass.


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