Cutting Oil as a coolant
 

This sounds silly but I am about to use Cutting Oil instead of water and coolant mixture in my rig. :drool:

In case some of you do not know (or forgot), Cutting Oil is usually found in CNC machines which help to clean and cool the part on which the operation (cutting/ modifying) is done. It has a black color and gets white like milk when added with water. The OIL-Water ratio is 1:2.

Why cutting oil? Will incase you people did not check out my last post, I am using a car's fuel pump for a 'water pump'. If I use plain water and coolant, the pump gets jammed and burns out within 24hrs of use.

With cutting oil, I have tested it to run 48hrs straight with no visible problems. I am still testing it.

I need opinions. Please do reply.

Re: Cutting Oil as a coolant
 

Is the pump submurged?

Re: Cutting Oil as a coolant
 

Yes :nod: . It is submerged. I have made a reservoir and have submerged it about 80% leaving the terminals, main water discharge and overflow hole out.

The pump function is very basic. It has an armature made from iron which has cuts (groves) making it like an impeller. A plastic followed by a magnet surrounds it. The upper part is in contact with carbon terminals. Moreover, these terminals will be in contact with the liquid during operation.

The main water discharge is from the top; the size of the hole is about 8mm. Water comes out with very low flow rate from an additional hole. I think that is the 'overflow'.


Water is suck from a hole (8mm) at the bottom of the pump. Pump has additional two very small holes at the bottom, which discharge the water with high pressure. I think these two holes help circulate/mix the fuel.


The pump has a pressure of 2 to 3 bars, 150 GPH when petrol is used. Pump size is, 52mm dia with 100mm length. Pump is sealed pretty well and I have to cut it using a saw to reveal the goodies inside.

Result with coolant:

I used an ordinary engine coolant (5-10%) and tap water for the job. Two problems arose:

1) After continues 20 hours of use, I could see some black residue surrounding the pump on the area, which is submerged in the coolant. I think it was the wear and tear of carbon terminals.

2) After 24 hours of continuous use, the pump gets jammed and thus the +ve terminal burns out.


Result with Cutting Oil:

Even after continuous 48 hours of use, the pump works like new. No residue formation is seen. The pump is clean and shines as new.

The drawback so far with the cutting oil is that the mixture is dense thus lower flow is observed as compared to water-coolant. Other thing that worries me is that I do not know the heat absorption properties of cutting oil.

In addition, I have heard that cutting oil (low quality ones) get expired. I do not know what will happen when it does get expire.

I am resuming the experiment today using the Water: Cutting Oil ratio 4:1.

I am waiting for comments.
:cool:

Re: Cutting Oil as a coolant
 

The lower flow is to be expected: the oil is thicker (density is not necessarily relevant) than water.

Check out this excellent guide, for more info:
http://www.overclockers.com/articles609/

Re: Cutting Oil as a coolant
 

Today someone who works with CNC machines told me that Cutting Oil takes away more heat as compared to water thanks to some chemicals added specifically for this job.

Regarding flow, he said that it would not be a noticeable difference. And that I can increase the water ratio for better flow.

Nevertheless, I will check it out practically myself.


Also, the merchant told me that cutting oil is made from some chemicals added to diesel. Oil thus, is diesel oil.

Excellent link btw.:)

Re: Cutting Oil as a coolant
 

Not likely, but oil is more appropriate for the high temps involved in CNC, and water is not always desirable.

We'll await your results.:dome:

Re: Cutting Oil as a coolant
 

The higher temps may be a secondary issue...the main reason for using oil around machine tools is to prevent rust, not just to the machine but also the part being worked on.

Re: Cutting Oil as a coolant
 

I have tested the rig for a week now. No problems found as of yet. I am going to post decent pics along with current block's diagram in a day or two, after when I resolve a few minor issues.

Also, instruct me how to test this rig's performance. I have no clue where to start.

As for now what I did is: took a butane torch and heated the block with blue flame for few mins. In just 5mins there was so much condensation that I had to abort the test as water kept coming in the way. It was like a mini waterfall!:D

The fan was running on 5 volts and the reservoir temperature had slightly risen. I did not had a temperature gauge at that instance but before the butane heating, the reservoir was 'cool' and after 5 mins heating, ‘normal' and it remained constant. Thanks to good gifted temperature gauge (hand).:hammer:

One more thing, I have noticed a green layer of liquid on top of the cutting oil. This is also present near the tips of the barbs. Algae?:uhh:

clocker I do not understand your signature message:p

Re: Cutting Oil as a coolant
 

Algae in the cutting oil isn't likely, But that is wierd. Could it be the water and oil foaming? Or some kind of wierd corosion that isn't rust.

Shane

Re: Cutting Oil as a coolant
 

I have done everything to avoid foaming as I was alerted by someone that 'foaming' would mean: oxygen will react with cutting oil and will thus expire it.

Only low quality cutting oil get expired and I am using one which's make was not even known to the merchant itself.:D

Corrosion...Could be. Yet reservoir and barbs are made from FeS, block is pure copper. Everyone I talked to affirmed me that these will not react with cutting oil.

I do not think plastic pipes would react. The pipes I am using are often used in natural gas lines.

Re: Cutting Oil as a coolant
 

I still do not have access to a decent camera. I used my cell phone and took these pics. Notice the black layer formed on the edges of the barb and 'T'.

This layer was green, I do not understand why it has changed its color.

Re: Cutting Oil as a coolant
 

True and false, in that application it does really well because it has a wetting agent that gets in really close to the cutting edge. Any wetting agent will help a little in that application and marginally in water cooling.

that kind of coolant can be really good, prevents corrosion, nice and slippery but it can get nasty, real nasty! we once had a machine goo up, how and why we have never determined. The coolant turned to a thicker consistency than paint!

The coolant part might work well, but I don't know about the fuel pump.

Jon

Re: Cutting Oil as a coolant
 

Typical reason is galvanic corrosion due to mix metals. If you're seeing this discoloration after a few days, it's a serious problem.

What metals are involved here?

Re: Cutting Oil as a coolant
 

Look at the synthetic cutting oils, they have a higher water content, with better corrosion and heat despation. I use to use one that was a 15:1 mix (h2o:oil). No foaming at all. It took a long time to get the film on the surface. Most was due to contamination by oils or from our cleaning bath. I only had to replace the mix every 6mo, not every month like petro oil was. The sys oil was for cutting stainless. We had another one for Al/soft metals.

Re: Cutting Oil as a coolant
 

JFettig:

Well, it has gone too far now. After over a week of continuous circulation, the cutting oil's color has changed from white to purple. I think the density has also increased. Pump makes a vibration due to load now.:bawling:
Checkout the pics.


You said “The coolant turned to a thicker consistency than paint!" ...what about its color?

bigben2k:

Metals involved are brass, Cu, FeS (or some alloy, for making 'T'). As for the pump, it uses Iron, Carbon, Magnets Cu terminals and small coils. I used solder to seal the block and T. Brazed the reservoir.


blue68f100:

Synthetic oil for Al and yellow metals, is that it? Will it last at least a year? As replacing it every six months is not practical.



What if I increase the ratio even further? A few teaspoons of the cutting oil (which I have at my disposal now) with a liter of water.

And what if I introduce a filter?

Re: Cutting Oil as a coolant
 

You've got galvanic corrosion, big time.

Probably red from the Iron, and blue from the copper, hence the brown color.

Copper and brass can get along very nicely, but the iron is throwing everything off. No filter will fix this.

I have yet to read about good solutions to prevent galvanic corrosion, and while the idea of grounding everything seems to make sense, it isn't a foolproof solution either. There are electronic solutions to this, but also just as many claims of scams on those units.

If you removed the iron elements, and use a mag drive pump that has a plastic impeller housing, you'd be back on track. If you were local to me, I'd gladly lend you my LGPC 2-MDQ pump.

Re: Cutting Oil as a coolant
 

Yes, bigben2k you are right :nod: (I have been told the same thing by someone else too).Pump is made from iron and steel so that means I have to drop the whole idea, which is not an option at this time.:nono:

One important factor I have noticed is that there is a 100V AC (strangely) in the whole rig when compared to ground. I can ground it to drop the potential to zero.
Plus, I think using some synthetic less reactive cutting oil might do the job. Please share your ideas regarding this.

Thanks for the offer but my aim is to make a WC system, which is cost effective, easy to make, made from junk (recycling) and extremely easy to homebrew. The whole thing should not exceed USD40.:D

If infact there is no alternate to the whole thing, I have another idea of using pumps found in 'washing machine'. It uses plastic impeller and might have the edge one needs. The only thing is that it will require AC voltage and I might have to mess with a relay.

Re: Cutting Oil as a coolant
 

Cutting oil doesnt prevent at all microbial / algae build up. Actually it seems it's a good place for nasties do develop, i dont remember if it's microbial or algae but they're responsible of respiratory illnesses for those who work around CNCs and such.
Also it wont really prevent galvanic corrosion, its main characteristics are related to lubrication and heat soak in high temperature / high mechanical constraints environments.

Re: Cutting Oil as a coolant
 

Respiratory illness could be associated with the diesel in it. It gives me a headache.

For nasties to develop, well I am confused here due to mix comments. According to me: It should not be a haven for nasties. Since CNC uses same cutting oil even years (Synthetic ones). They just filer impurites out I guess.

I am looking for quality cutting oil, maybe use Gulf Cutting Oil www.gulflubricants.co.uk

I wish I could pass you the specs of this oil. Yet again, first let me check locally what we have.

Re: Cutting Oil as a coolant
 

Right then, I have been a precision engineer for 12 years and have worked with all kinds of oil/water emulsions.Heres are some points you should consider:-

1: All modern synthetic coolants do degrade no matter who you buy it from or how much bull the salesman tells you.

2: The concentration of these emulsions is usually between 4 and 8% for which you will need a refractometer to measure.

3: The pH value of these emulsions is dependant on their concentration, usual pH values for modern emulsions are around pH 9 .

4: These emulsions are near perfect for bacterial growth, modern emulsion manufacturers add bacteria to these emulsions to prevent nasty bacteria growing in its place. This is why the concentration, pH must be kept optimal.

5: Another factor is that the emulsion can split into water and oil again, usual if left stood for a long time or if the concentrations and pH are not correct.

6: Also these emulsions may dissolve plastics (all rubber based materials) for example you rig has been running fine for a while, the hose is perished, and leaks. Not good.

7: Discolouration of coolant is usually due to chemicals leaching from plastics/metals.

8: Foaming is an issue with coolant, you can buy anti foaming additives to control this.

9: Concentration pH values should be checked weekly and altered accordingly to maintain the nice bacterial culture. coolant should be changed every three months,washing all parts, rinsing with biocide to kill evrything, leaving to dry properly and then replacing coolant mixture.

Now then I'm not trying to put you off using these emulsions , it is a good idea, but you must be prepared for the amount of attention these emulsions need to prevent/(slow down) their degradation. The chemicals in these emulsions are carsenegenic and ecologically unsound and must be disposed of properly they are poisonous to all aquatic life.

I hope this reply is helpful to you and has information that you were unsure about.
Good luck with this I too have considered it and decided against it for the reasons above, but i would be interested in seeing the results of heat transfer coefficients relative to a conventional water/glycol setup.

cheers chris.

Oh and the best manufacturer i have come across is (Rocol synthetic cutting fluid.)

Good luck m8
;)

Re: Cutting Oil as a coolant
 

Finally, got the attention of an engineer who played with cutting oil :) . I do not know how to start as you have reported such cons which suggests a total refutation of cutting oil thing.

Please, if there is an alternative to this, let me know (alternative to liquid only, the fuel pump is the best ‘water pump’. I will explain that in my new post (Swiftech MCP655 vs Fuel Pump). Nevertheless, here is what I have been upto:

I got Synthetic cutting oil sample from Gulf Oils (Gulfcut Soluble CB-2). Its got amber color, which becomes very light when mixed with water. The specs are attached (doc file).

Please go through it and let me know its potential. The merchant did tell me that it would not need attention for even a year. And that it is soluble to a ratio of 64.

For the discoloration, it could be one of two reasons since pipes are in its original condition.

Reasons:

Galvanic Corrosion (due to a variety of metals involved) plus I noticed green layer formed outside of the brass reservoir. (Solution: Changed the reservoir made from brass to plexi, cast acrylic transparent sheet)

Reaction with the solder I used to seal off barbs and holes in WB also Ts. Since they got leaked and I know it wasn’t cold solder. I re-soldered this time used lot of heat, quality flux and solder wire, it never got leaked again. (Still am going to braze it)

--------------------------------------------------------------------------------------------------------

Also the merchant said that this very synthetic oil is non reactive (I explained him the metals and plastics involved and my past experience with low quality oil).

And, I used some of this sythetic cutting oil with ratio of 1:30 (cutting oil: water). I had placed this in a plastic soda bottle, which is sometimes in direct contact with sunlight. It smells the same and no discoloration or separation is observed. If you want, I can supply pics. It has been a month now.

Merchant did say it has some antibacterial thing in it. (If not, I would have introduced something my self).

Health issue, yeah that is something NOW what worries me. I know how that low quality oil tastes like...... :drool: (like diesel, else somewhat tasteless)

Charls, thank you very much for replying. Do not disappoint me by keeping me waiting.

Re: Cutting Oil as a coolant
 

Glad to see everthing worked out.

Sorry I didn't reply to your post on Synthetic oils. But you found your answers. Syn are the only way to go. The stuff I used started needing attention after 6 mo. But it was being used actually used as a cutting fluid. Syn shine when the conditions are down right nasty. That was the reason they were developed.

Re: Cutting Oil as a coolant
 

I may have found a workaround for your problem: nickel plating.

It involves some nasty chemicals, so you might consider contracting this out.

Some info:
http://www.pfonline.com/articles/pfd0015.html
http://www.pfonline.com/articles/040102.html
http://www.proplate.com/nickel1.htm
http://www.proplate.com/nickel2.htm
http://www.caswellplating.com/kits/electroless.htm (also on eBay).

I'm looking into this right now, for a heat exchanger that I just picked up.

Re: Cutting Oil as a coolant
 

hello again chap i cannot stress more that its a great idea and do try it, but don't forget the people that tell you it won't react are salesman.

i knew a chap who went to a machine shop show saying how non-toxic his coolant was and he used to demonstrate this by drinking half a pint on the stage.
:hammer: idiot!!!
he died 8 years later of stomach cancer.

my point being they just want your money.;)

Re: Cutting Oil as a coolant
 

bigben2k:

Is this nickle plating commonly refered to ask CHROME? Some of my friends chrome car parts, I can ask them to chrome the pump. Other than that, I have changed evertyhing to plastic (besides WB and it's BARBS, which I assume wont be that trouble). I am going to give a test run and see.

Chrome would make the pump look nice. :)



charlie b:

LOL, drunk it! No doubt the stuff contains chemicals that should be lethal.

Anything that is not edible is lethal (so goes for radiator coolant even). BTW what ratio should I set for this job and do I need to check and maintain PH value (I do not want to do this step)?