Pumping cutting oil with a coolant pump?

[cuslog]

Will a typical coolant pump pump ~20wt cutting oil ?
I've used water soluble cutting lube before, no problem there.
Now I have a project that uses rather expensive reamers and the mfr. recommends using petroleum based cutting oil rather than water based.
Would just like to know if it will work or not before I dump ~$100 worth of cutting oil into a coolant tank that's not easily accesable.
This is on my Nardini 16 x 40 lathe, IIRC, its about a 1/3 hp 3ph pump - "Centrifugal" I think - not high pressure or volume, kind of like a sump pump.

 

[RobinHood]

Can you take the pump out and stick it in a 5 gal pail temporarily for a test?

The old K&T coolant pumps will work fine with cutting oil. Don’t know what type of pump they use though - gear or centrifugal. Steve Summers has his mill setup like that.

 

[cuslog]

Can you take the pump out and stick it in a 5 gal pail temporarily for a test?

Not easily, lathe is backed up against a wall, tank, pump, chip tray, electrical panel all open out the back. To get any of them out, I would have to pull the lathe (2500 lbs) out, put it back and then re-level it again. Its not the end of the world if I have to move it, I do have a toe jack and machinery skates, just rather not if I can avoid it.

 

[RobinHood]

Ah, that would make it a bit tough.

Could you just use a squirt bottle to lubricate during the reaming process? That’s what I have been doing, as I don’t particularly like coolant all over the machines - might be different if i were to use mineral oil based cutting oils...

 

[Tomc938]

Or you could go low tech. A jug with a hose coming out the bottom suspended over the mill. Gravity feeds the oil. I used to do that with my small lathe (6 x 18) and an IV tube. Was able to control the flow just like an IV, and worked great. If it's just a one-off, I'd give it a try.

 

[cuslog]

Application is reaming a rifle barrel chamber. Many that do this more than just occasionally have gone to a muzzle flush system where cutting oil is pumped in at the muzzle end (not high pressure, not high volume) to flush chips out the back end. Traditional way was to ream .050 or .100", pull out, brush/flush chips, squirt oil, back in. With a muzzle flush system, cutting oil is continuously flowing and no need to stop/ start to clear chips. Besides being much faster, guys using this method report much improved surface finish in the chamber as well as much longer reamer life. I am wanting to try this and my thought was " why couldn't I just use the existing coolant pump on the lathe ? (I think a bit of pressure would be needed to flush chips but not so much its spraying everywhere).
Reamer Flushing system - YouTube

 

[RobinHood]

Howard, that would be a very clever way of chamber reaming if you can get your existing coolant pump to do the job.
Do you have a data sheet of the pump that you could use to determine if it would pump the more viscous cutting oil? With ~ 20 weight oil, you might need a small gear pump. It would for sure handle the oil with sufficient flow and pressure to ensure proper chip evacuation. If it made too much pressure, you could always have a bypass valve in the system to regulate and set your demand as needed. If you ever got into drilling & rifling barrels, you’d already have the oil pump.
Maybe something from PA like this would work?
https://www.princessauto.com/en/85-gpm-hydraulic-gear-pump/product/PA0008375388
Run it off the accessory side of the lathe with a belt when you need it. This way you could still use the regular coolant system for all the other times.

 

[PeterT]

Oil viscosity is one factor as mentioned, but where it can get interesting is seals, gaskets, O-rings etc. Usually those materials are pretty universally stable, but some can swell or break down in the presence of certain hydrocarbon products. On our methanol engines some of the carb/regulator parts were made from a kind of silicone looking material. Methanol, gasoline, most additive oils, no problem. But certain tool oils intended to be after-run or having water dispersant properties caused grief. I remember soaking one in WD-40 & witnessed visible distortion & breakdown. Not that you would use WD-40 but just saying a blend of 'oil' and other additives might have unintended consequences. Maybe there is a pump spec sheet or some idea of seal kit composition.

 

[johnnielsen]

I switched to a screw pump/gear pump/piston pump for heavier viscosities. and collected the oil with a separate pan placed on the ways of the lathe.

 

[ShawnR]

What about a pressurized tank with coolant/oil in it. Pressure regualor on supply of course. Needle valve to control the output flow. Does not recycle unless you collect it and pour it back in but for occassional use, I think it would work. I have a small compressor tank that I thought would work well, although hardly necessary. I think a pressure of 5 to 10 lbs would be lots.

 

[ShawnR]

 

[cuslog]

Thanks for the input guys.
Crawling through my junk piles, I see I do have a (I think) centrifugal coolant pump I somehow acquired - sitting loose, out in the open.
Think I'll try to jury-rig it up and see if it'll move some 20 wt cutting oil. If not, I do have 2 or 3 gear pumps I could try. I was just hoping the existing sump / pump etc. already in the bottom of my lathe would work (that would be easiest and simplest - but nothing is easy or simple is it ?)

 

[historicalarms]

Just my own thoughts on chambering & cutting fluid.

While I havent cut a lot of chambers, probably 1/2 dozen rifle chambers and I have a .45 colts reamer that I have cut 15 chambers with the same reamer and can see no degradation in cutting ability in 4140 annealed barrel stock.
Personally I cant see a benefit to a flood coolant having to be used, it will work of course but I think " brush on" is just as good in this endeavor.
First of all a completely sealed system would have to be used to reliably clean the cuttings from a reamer...chamber reamer cuttings are long & heavy compared to regular reaming. The pressures used for cleaning common scarf from final bore sizing finish-barrel reaming's run at a recommended 300 psi. With an enclosed system to achieve that level of pressure, it would be impossible to watch your reamer during use....I consider this imperative when chamber reaming.
Chamber reaming requires a lot of short "ins& outs" of the reamer to brush cuttings off and I simply re-brush with copious amount of cutting oil after a thorough cleaning at every "push in". Very good chambers & reamer life can be had this way....but one very important thing ....don't try to rush the job, clean the reamer 20 times minimum for each chambering job.
Another comment that you can use or not...I have used both water diluted cutting oil & undiluted straight from the jug and have been very satisfied with the finished chambers...but I will say again....clean often. You will feel the reamer start to cut at every pass through the hand wheel and watch your dial....don't wait until you "feel" the reamer starting to bind before drawing it out.

As you said, reamers are expensive landed at our door so do as you choose....the above is just my experience.

 

[Brent H]

Just throwing it out there : have you thought of the kool mist type cooling where you use compressed air to draw the coolant and it mists onto the part - right directly? It’s not quite the same as the flooding from oils etc but it is a lot cleaner and the stuff doesn’t rot in the tank.
I apologize if this has already been discussed…..

 

[cuslog]

Brent, no worries, thanks for your thought. Actually, I do have one of those (not the cool Mist) but I do have to question whether air / mist would clear the chips - it would go on at the muzzle and the reamer is ~ 27" down the hole.

 

[cuslog]

Update for an old, dead thread;
I had asked whether or not a centrifugal pump would pump ~ 20Wt cutting oil with enough force to clear chips from a .450 dia. reamer that was ~27" down a .450 dia. hole. (a through hole - oil pumped in from the end opposite the reamer).
Well, I finally got some 20 Wt. cutting oil, dumped some into a cut off windshield washer jug and jury rigged a coolant pump off an old 12 x 36" Chinese clone lathe I had a few years ago. The answer is "Yes" it did pump the oil at what should be enough force to clear chips from a reamer. From a 5/16" dia. fuel grade hose, it would pump a full dia. stream a good 8+" on the horizontal plane and if I pinched it down, it would spray quite a bit farther. Not a lot of pressure - I'd estimate it at about 10 ~ 15 psi. but surely enough to flush chips from a reamer.

 

[Susquatch]

Update for an old, dead thread;
I had asked whether or not a centrifugal pump would pump ~ 20Wt cutting oil with enough force to clear chips from a .450 dia. reamer that was ~27" down a .450 dia. hole. (a through hole - oil pumped in from the end opposite the reamer).l

I had not seen this thread until your last post @cuslog . A couple of comments:

1. I purchased a Flushing System from Sinclair (now Brownells), but only used it once on a junk test job. I didn't like what I saw. A custom barrel is worth more than a reamer but together they are big bucks plus your time. I have cut maybe a hundred chambers and I agree with @historicalarms. I would not risk "plowing ahead" without regular inspection and cleaning. Those long curls are hard to flush and I simply wouldn't risk ruining anything with a flushing system. As the reamer gets close to the hilt, I don't even know how it could flush them! I don't brush my chips, I blow them off the reamer with compressed air into an old garbage barrel with a hole in the lid and filled with old paper towels, and do the same out the chamber between every push with a shop rag hanging behind the back end to catch the chips and spray. I also drop/drip fresh cutting oil on the reamer. My most often used reamer is a Bisley 308. I've cut maybe 20 chambers with it and it shows no sign of wearing out. It's a lot more work to stop, clean, oil, and push than just plowing ahead but it's a time tested way of cutting a chamber.

2. If you ever do need it, most reamer makers will sharpen their Reamers at low cost.

3. I use a high sulphur based cutting oil called "Viper's Venom" that I get from "The Reamer Guy" in Vancouver. I buy it in bulk and use it as my cutting oil for all work on ferrous metals of all kinds not just barrels. It has become very popular over the years and is now available from almost everywhere including Amazon in quart size bottles. It's thick sticky awesome stuff. It will survive 3 passes on an outside turning job. It has never failed me.

4. Greg @ Gretan sells a varient of your system for not much coin. I believe he sells parts and whole kits.

5. Here is a very expensive but effective coolant catching system if you have decided to go ahead and run coolant. I'm not promoting this, but I saw it a while back and thought it might come in handy if I ever did want to run a coolant system on anything. As is, I really don't want to fill my tray with oil, and a tray on the ways isn't foolproof, so I have not tried it. I'm not sure how you clean a reamer off with that thing on there anyway.

If you do try to run a flushing system and especially if you decide to keep using one, I'd love to hear your outcome thoughts on it.