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Grinding coolant recommendation

ratbldr427

Titanium
Joined
Mar 21, 2006
Location
jacksonville,fl.
I have a G&L 460 SG.Very nice grinder,had it for over 20 years and never set it up to use coolant.I have a tank and pump and the grinder is set up to use coolant.

The only reason I haven't used coolant is because of the intermittent use it gets.I may use it all one day then not use it for a month or more.

So is there a coolant besides oil that will not degrade,or leave a sticky mess when it dries that will keep for a long time?
I'm using Cincinnati Cimcool in the lathes but I think it has changed since we started using it years ago.It seems to be sticker and notice that some rust build up lately that I've never noticed before.

The reason I want to now use coolant is that I cracked a 14x2 wheel last week.Scarry! My fault as I think I overheated it grinding some larger than normal pieces.

Any good recommendations.
 
I have a similar situation. I have a wet grinder that sits for months at a time. I use TRIM E206 that I cut to 5-7%. There is no odor or smell problem, no growth in the coolant and best of all, NO RUST. The coolant tank is open to the atmosphere and over time evaporates but nothing is left but the swarf.

Tom
 
I stick the return hose into a filter sock to catch the swarf.
Once I did let the coolant evaporate and what was left at the bottom of the tank was super concentrated coolant that I brush on parts before grinding.DSCN0450.jpg
 
Thanks for the recommendations.
I made my tank out of some aluminum 1/4" leftover diamond plate.I put a separator plate between the intake side and the pump pickup.I made a fine mesh ss screen that the coolant dumps on first into the first stage.I also salvaged a large magnet out of a servo motor that I will put in a plastic bag in the first stage.

If that is not enough then I might use some more ss screen between the first and second stage.
 
Coolant tank

Here are some pictures of the tank,all I have to do now is find out what the heck I did with the motor! 20200323_112430.jpg20200323_112500.jpg20200323_112616.jpg20200323_112532.jpg
 

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Here are some pictures of the tank, View attachment 282625
Rat, usually in a grinder tank you want it long and skinny with several dividers but anyway, I notice in this photo a bunch of holes in your separating wall. What you generally want to do is have a few stages where you make the coolant go over the wall, so that the swarf settles out and only water carries over to the next settling area, capiche ?

I don't believe your freeflow model will work as well :(
 
I'm using Trim 690xt in my grinder (and mill and saw and....) at about 2% concentration and it works very well. I maybe use the SG once every couple of months and this tolerates it well with no smell or fungi even though it's filled with tap water.
 
Rat, usually in a grinder tank you want it long and skinny with several dividers but anyway, I notice in this photo a bunch of holes in your separating wall. What you generally want to do is have a few stages where you make the coolant go over the wall, so that the swarf settles out and only water carries over to the next settling area, capiche ?

I don't believe your freeflow model will work as well :(
Technical term is weir. They work by creating low velocity zones in the fluid to allow the particulate to drop from suspension. The term for this period is retention time and if someone wanted to get very specific
they could calculate the proper volume to allow a certain percentage of solids to drop from the fluid stream in each section based upon particulate size and some other parameters.

The lack of basic filtration principles in machine sumps kind of boggles my mind.
 
The ss screen over the holes is very fine and I will have a very strong magnet in the front part.The fluid path will dump on the sloped plate and roll over the magnet then will reverse and go up to and over the screened separator plate.So emanual you think that the screen is over kill? If that is not enough then I'll add a filter over intake.Printing has some nice filters for the water system on the presses if I need to get every last particle out.

I mostly grind low to medium carbon steel and only occasionally some hardened steel/knives,repair parts.Nothing super critical.
 
Hard to tell from the pictures but the screen is about 10" above the bottom of the tank.I was thinking the screen may be to fine but since it is vertical I'm thinking the particulate will tend to fall off and due to the low flow rate won't pack up.Any way as soon as I find a motor I'll know.
 
Update,I found a nice 56c,TEFC 1/2hp 1ph motor in our motor pile.I only needed a 1/4hp and 3ph but this will do just fine.

I couldn't find my servo magnet,it's probably stuck on something somewhere.Our fl mechanic told me to stop crying and see if I could use one of some pm dc motor armatures he had saved,just because they were neat!
Perfect,much better than the servo mag.I am always amazed every time I use a rare earth magnet at the amount of holding power they have.
I used some scrap plastic tube machined for a close sliding fit,blind end and machined to a 3/16" wall on the end the mag sits.
In operation,pull it out of the tank with all the magnetic swarf stuck on the end(the aluminum tank helps)hold it over a trash can and pull the mag out to deposit the swarf.20200407_140507.jpg20200407_140450.jpg20200410_143237.jpg20200410_143129.jpg20200410_143054.jpg
 
The tank is an exact copy of the oe G&L tank except for the added screen and aluminum body.The pump has no numbers on it so I assume G&L may have made it.It has a spring loaded floating rotor,cf vanes on both sides.Have not seen that before?
When I bought the grinder G&L was still in business.The parts man I dealt with was really nice and sent me all the documention he had including the tank drawing.He also sent me a copy of the original invoice.NAS Jax, paid $82k for it in 1970.Don't know if that was the going rate for grinders that size at the time but that seems quite expensive.
 
To add ,one side effect of working with rare earth mags is that they will magnetize damn near anything with iron in it.

My 6jaw lathe chuck is now a magnetic chuck!What a mess.
Along with my Mits coolant proof calipers.

As soon as I get time I will pull the jaws and chuck and put them on the G&L mag chuck and run a demag cycle along with my caliper.
For years we had a large degaussing adjustable magnet.No one knew how we got it or what for.Now that I need it no one knows what happened to it.
 
thats not my experience. i have magnets everywhere and nothing gets magnetised. sometimes a parallel or caliper is magnetic, but thats from rubbing, they never get close to a magnet.
 
dian, you have not experienced any powerful rare earth magnets apparently.That armature when stuck on any metal surface has only a tangential contact since the magnets are radias faced.Easily requires over 50lbs pull to remove it.If the mags were flat I don't think I could pull it off a flat metal surface.
 
The combination of aluminum, cast iron, steel, and brass is very unforgiving when immersed in a electrolyte. The aluminum will rapidly go into solution unless the coolant concentration is maintained. When shopping for a coolant make sure that there is a corrosion inhibitor that can handle mixed metals. The inhibitor may gradually be consumed during use.

If you do a search on this site using the key words " grinding coolant" you will find some recommendations. Your requirements are coolant stability with infrequent use, mixed metal corrosion inhibitors, a water base and safe for disposal in a municipal sewer. The last requirement may not be possible with a semisynthetic or soluble oil based coolant. The Cimcool products are in this category.

Pay close attention to the coolant's safety record. You may also want to consider installing a inexpensive wet vacuum cleaner with a pickup near the wheel and a exhaust hose routed to the outside.
 
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Robert R thanks for the heads up.I hadn't even considered that.I bought the Trim coolant.I will check the compatibility issue with aluminum.Disposal is not an issue.Whatever cannot go down the drain we have a 5k gal tank for haz wastwater that gets pumped regularly.

The only reason I used aluminum was because we had just finished building a catwalk on one of our older presses and had a lot of leftover pieces.I'v often wondered how much money I've saved the company using leftovers and scrap to make parts over the years.
 
Time to end this saga.Had to fix a small leak and make a dust cover.The manual calls for 35 gal.I decided that 26gal was enough.I used Trim 690 coolant.The specs just say that it is compatible with aluminum brass and iron.

I had added a wash off line to the back of the saddle trough to keep any build up down.
When running it is so smooth that it doesn't look like any fluid is moving over the plate and through the screen.

I tried to get a picture of the floating crap in the weir side and the clear fluid on the pump side.So the screen is doing its job with no drop in level.I think the grid is 250 or 325,so the openings are less than .004".The weir plate is removable in case I have to clean or modify it.

The tank area and pump volume are pretty well matched,good flow with no turbulence.

emanual g mentioned that a proper tank would be skinny with multiple weirs.That is not quite true.If I were to cut my tank in half and make it twice as long the volume wouldn't change but the velocity across the weir would double causing more turbulence carry over of solids needing an additional weir.Like a self fulfilling prophecy(skinny tank and add more weirs).Unless of course you reduced the pump volume.If you need more than one weir(talking about grinder tanks this size)then the tank area and flow are out of balance.20200417_104417.jpg20200417_130454.jpg20200417_104333.jpg20200417_104525.jpg20200415_102400 (1).jpg
A picture of my 6 jaw magnetic chuck!
Overall I'm pretty happy with the results.
 








 
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