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View Full Version : Canola oil as a coolant ?



cropwell
11-05-2014, 01:24 AM
I have a flood cooling system for my lathe and I was looking at various water free alternatives. There seems to be no thread about using cooking oil on this forum. I looked on another, but there were only stupid comments.
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Rapeseed oil (Canola) is cheap, has a high flashpoint and seems to be OK. Vegetable oil based miscible coolants are on the market anyway.
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Anybody got any useful info on this topic.
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If you want to do the jokes, look on that other forum, they are all there:joker:.

Cheers folks !

Rob

m_c
11-05-2014, 09:13 PM
Why do you want to go water free?
Unless your lathe specifies pure oil, or you're machining something where pure oil is a better option (not likely given you're trying to do this on the cheap!), then there's no real reason not to run soluble coolant.

It's worth mentioning, the vegetable based oils will still have additives to improve extreme pressure properties, and also to inihibit unwanted things growing/living in it.

cropwell
11-05-2014, 10:35 PM
I have just spent nearly 3k on a new lathe. The old one had a sudsoil system and I still have 2l of the undiluted stuff left. It stained the bed of the little bugger and the stuff turned green when I was machining brass (a lovely pale sage green). So I am a bit wary of water on machinery. I am using some surplus engine oil diluted with paraffin at the moment in a hand sprayer. This seems to have a good cooling effect but I don't like the idea of flood cooling with it. My reservoir tank takes about 10litres, so that is under 20 in budget engine oil terms and 8 for veg oil.

Vegetable oil (especially rapeseed) is 8 for 2x5l at ASDA and has several advantages :-


It is cheap
It has a high flashpoint and autoignition temperature
It has good lubrication properties
It is non-corrosive
It is not carcinogenic
It won't stain the machine
You can buy it at most supermarkets
It doesn't smell that much
You can recycle it for bio-diesel
And it's cheap.



So why does it not seem to be being used. Is the thermal transfer not good ?

:stupid:

Jonathan
11-05-2014, 11:50 PM
So why does it not seem to be being used. Is the thermal transfer not good ?

Yep - just compare the specific heat capacity of water and your favorite oil. Oil does 'lubricate' better (i.e. lowers the co-efficient of friction between the tool and material more), so less heat is generated in the first place compared to with water, but I think that effect is only dominant for materials that are very hard to cut - i.e. the ones where people recommend using neat oil.

m_c
12-05-2014, 12:28 AM
I've always used soluble oil, and never had any issues with staining, however I am aware there are some that are notorius for causing residue build up.
One big thing to be aware of is soluble oils can be pretty specific for their applications, and I'm guessing that whatever you have isn't suited for brass (some suppliers classify it as yellow metal).

I'm currently running Gulf Cascade HD-S, as it's capable of handling most metals and processes, however the smallest quantity it's available in is 20 litres. The choice for cutting oils in small quantities is very limited, so you either have to run whatever you can find and hope it works, or buy more than you're ever likely to use.

Jonathan
12-05-2014, 12:32 AM
I've always used soluble oil, and never had any issues with staining, however I am aware there are some that are notorius for causing residue build up.
One big thing to be aware of is soluble oils can be pretty specific for their applications, and I'm guessing that whatever you have isn't suited for brass (some suppliers classify it as yellow metal).

+1

I use Castrol Cooledge BI (http://www.castrol.com.ua/catalog/Cooledge%20BI.pdf), mainly because I got most of a 20L container cheaply. I've not needed to use it on brass, but it says it's suitable in the datasheet.

Christian Knuell
10-09-2014, 09:27 AM
Hi,

rapeseed oil works well if applied directly to the workpiece and removed afterwards. I've used it a few times for cutting stainless steel.
But: I would never put it into a machines coolant system. Fist: it is quite thick - but most important: it will rot and become a total mess after a few months.

Christian

cropwell
10-09-2014, 12:58 PM
Yes - I found that out the hard way, fortunately I drained it out before it set.

EddyCurrent
10-09-2014, 01:12 PM
It's not the oil I've fancied,
Because the bas$*rd goes all rancid.

(you didn't know I was a poet ! :tears_of_joy:)

Hallettoil
17-10-2015, 04:31 PM
Not that bad an idea Rob really....BUT...you can see the advantages...now look at the disadvantages..

The viscosity is a little on the heavy side...your pump will be straining a bit


What a reet mess you will be in.... it'll be all up the walls.... all over you....all over the floor...the dog'll walk in it..tread it into the house...jump on the bed.....

What about the smell? AND don't say you can bath him!!

I feel a divorce coming on!!

Do YOU know of any engineering companies that use it? 45 years in the Oil Business and I don't .

It has been done though I do know


As a lubricant...it's fat...so got to be ok..... but get it hot and you will be coat everything with gummy "Chip Fat"... smells ok though.

Use the proper gear..see my article today on Coolants

R

IF you really do want to go down the neat oil avenue...I'll be glad to advise...but..... be it on your head

ps I've just save you have HALF you own :-)