Coolant filtration?

[projectnut]

My coolant reservoir has this little filter built in:

View attachment 422576

I added a plexiglas sheet and a seal to reduce evaporation:



And here is the sponge I added at the bottom of the chip/coolant tray where the coolant return is:

Your mill uses a reservoir and pump system similar to my Baileigh cold saw. This saw also has a screen in the coolant return trough to catch the majority of the swarf before the coolant returns to the tank. I like the idea of adding a cover to minimize the evaporation.

Two of my other saws have coolant systems, but neither has a useful filter. They both have large coolant tanks with partitions about 2/3 the height of the tank. The coolant returns to the opposite compartment it's pumped out of. Returning swarf settles in the return side of the tank. Coolant doesn't flow to the pump side of the tank until side it reaches the top of the partition in the return side.

Here are a couple pics of the Baileigh saw and coolant system. The first picture shows the tank and built-in filter basket. If you look closely at the second picture you can see the return coolant port in the center. At this point there is no screen installed of the trough.

The third picture is the Racine power hacksaw. The return tank is behind the long horizontal door. The pump is behind the smaller door at the rear of the machine. If you look closely, you can see a coarse screen by the paint brush that supposedly will keep the larger swarf from entering the tank. It's sort of a moot point in that all the saw swarf is small enough to pass through the screen. The final picture shows Startrite horizontal bandsaw. Like the power hacksaw it has a 2-part tank in the center of the base, and a screen in the tray above it. Also like the hacksaw the screen is all but useless for filtering out the swarf.

 

[Aukai]

Thank you everyone so far, that has helped a lot. My welding table on casters will be on the backside of the lathe, while it is portable, it's a nuisance, so I'm hoping to cut down having to move it too often.

 

[pontiac428]

Filtering isn't important for cutting oil because gravity does that job instead. Ultrafine metal particles like grinding dust are still high density/low surface area and oil doesn't interact much as the particles settle. Even Mobil's tech pdf on Mobilmet says to settle it for 3 days if it gets cloudy and it will return to clear.

The design of the reservoir matters. A reservoir should have a spillover baffle that acts as a return sump wall for returning oil, and the sump volume should be a gallon or so in order to gain residence time for fallout to occur. It should also have a skim baffle just higher and offset to the sump side of the spillover baffle. When the oil level is filled above the bottom of the skim baffle, it skims any carp off the top of the oil on the return sump side to keep it away from the pump.

 

[Aukai]

I'll have to see how ACRA/Sunmaster do their coolant tank configuration when I get it here.

 

[mksj]

If this is for your lathe, I would recommend not using it. The most common would be a FogBuster type system. I currently use that type of system on my mill and it works great for both ferrous and non-ferrous metals. I would use the same thing on the lathe if I were turning materials continuously. Flood coolant on the lathe is very messy, mostly used for exotic metals, probably advantageous for some types of stainless. I previously used flood in my horizontal bandsaw, there is a plate with holes at the first catch point which takes out the larger swarf, the tank has a finer strainer on the return, the tank is baffled so most of the swarf drops out at the mid-tank baffle. Sludge does buildup can can eventually spillover to the pump compartment and clog the pump. Different machines make different size chips, mills and lathes most of the chips are captured by a screen filter.

When I did use flood, I used a 10% emulsion of KoolRite 2290 and added it to the tank, I just added some water to a fill line when it got low and did not worry about it being exact. Cut a lot of steel and aluminum and really helped to clear the chips. Once a year I would empty the sump. Never had an issue with the sump going bad, even with the heat in Arizona, other solutions got nasty after several months. I also use the KoolRIte in my mist system, been working very well.

 

[Aukai]

With the lengths I am drilling through the aluminum bars 9-10" I need to carry away a lot of heat. I am using the Noga misters with Kool-mist, I was also trying alcohol to get better cooling, my problem now is the misters are blowing back in the coolant, and not siphoning. I'm sure I'll try cutting with the 424 too, but I want to see how it does as an external heat remover, I have even used a chiller, but it made my 80 gallon compressor do 100% duty while drilling.

 

[ddickey]

I'll have to see how ACRA/Sunmaster do their coolant tank configuration when I get it here.

The tank is accessed from the TS end. There's a screen on the bottom of the chip pan. MKSJ is right it is a mess. If you end up going w/the Mobilmet you'll see. lol I use(d) it for drilling and power tapping. If you plan on using for turning you might consider replacing the ball valve with a needle valve so you can easily dial in flow. Every time you change a tool it will be dripping with oil. At least you won't ever have a rust problem.
I eventually lost enough oil onto my shop floor the pump started to cavitate and I never bought more. I intend to but I won't use it again unless I have some shields fabbed up.

 

[Aukai]

I'm hoping that just letting it run on the barrel with no cutting tool it won't sling, but newbies gotta learn, experience is something you get right after you needed it.

 

[mksj]

A Fogbuster type system pressurizes the fluid tank, I have mine so I can run either at low PSI with different amounts of air/coolant if I want more wetting/lubrication. I tried kool mist and didn't like it, the emulsion sticks better to the metal and decreases the friction/heat. These days I am using much lower pressures, like 25 PSI on the air line and 5-10 PSI on the fluid line. I have two needle valves so I can also adjust the flow both air and coolant. I use it with a Noga head. I ended up with a larger bore solenoid for the fluid as I had some clogging through the solenoid at low pressure. Idea is to not use high pressure which cause a lot of aerosolization. You could use a single air solenoid for both sides, but I add a solenoid after the fluid reservoir so the fluid flow stops when turned off and just what is in the line will drip out.

 

[Aukai]

Impressive, I saved that, thank you.