Blanchard coolant filter/flocculant

[Rotary Science]

I have a Blanchard 11-20 that I use to grind the wear out of cast iron faces on rotary engine side plates (like the bore of a piston motor, but layed out flat). I then lap them on my lapmaster for final surface finish. In order to keep lapping down under 2 hours per face (3 faces at a time) I am using a very fine grinding ring wheel, I believe 120 grit. I have issues with that grinding process, but I will ask for guidance on that later.

My coolant gets to be black (starts clear) after 20 or so parts go through the machine. I don't know how that is affecting the performance of the coolant, but I imagine it is not helping. I have let it try to settle out for weeks at a time without running the machine and the coolant is still totally black.

My question is, can I add a flocculant to the coolant to drop the solids out of suspension without dropping the coolant oil out with it? Or am I going to have to filter it externally to the machine?

Thanks,
Mike

 

[Rotary Science]

Alright. I will document my findings so far, I can't find any info on flocculant anywhere else online so someone might find this useful.

I tried flocculant on a small scale and it does not seem to drop the coolant out of suspension, so that might be good info for someone for a less specific scenario. It however does not seem to do the job of clearing the coolant as well as I would have hoped in my scenario. It drops a bit of the solids out of solution and makes a still very liquid layer of heavier stuff on the bottom. It is not solid enough to rake out of the base of the machine/sump so I think it will just keep mixing back into solution.

I tried the flocculant on my VMCs coolant as well and it didn't drop that oil out of solution either.

I ordered some filter housings and some 5 and 1 micron filters plus all of the fittings I need to build a filter system. I will update that with pictures next week sometime.

Hope someone finds this useful.

 

[DDoug]

There were (3) coolant tank set-ups that I have run:
1. straight tank under the machine a 'Bathtub" that you Hoe out.
2. An add on electric motor and drag chain system for the bathtub.
3. A different Hi-production set-up where the bathtub is kept empty, all coolant & swarf flows out the back into a multi level system of riffles, and a larger setting tank.

On a Campbell vertical grinder (I did not run) I saw an
add on hydrocone system, had (2) centrifuge cones, and a filter paper belt.

 

[guythatbrews]

The problem with a flocculant is the floc needs to be removed. It's very fragile and can easily be stirred back into solution, although it will settle again. The alum will increase particle size to a point where it can be filtered but not sure of filtration rate needed.

Alum works and is cheap. Maybe a pound or two. Alum lowers ph use soda ash to raise ph.

Disclaimer: never tried in a grinder but works great in a swimming pool.

 

[swarfless]

Stupid question: would a magnet drag the iron out or are there other sources of the 'black' ?

 

[gbent]

Is the "black" particles of carbon? You have decided them harmful, but does the surface finish deteriorate from the first piece with clean coolant to later pieces with black coolant?

 

[Rotary Science]

I have noticed the wheel will load/glaze faster as the coolant gets darker. I haven't tried a magnet but I will this afternoon.

This setup is far from ideal, but it is as much grinder as I can power right now. The wheel has near constant engagement on the part, and it is hard to shed the spent grit out of the wheel. The dirty coolant seems to be loading the pores in the wheel and making the problem worse as time goes on. It will glaze the wheel and burn the part. Then I have to lift the head, chuck a chunk of scrap, plow down on it to dress the wheel and finish the part before it glazes again.

I really need a dresser. If anyone has one they are not using, I would be interested in buying it. I feel like that would bandaid my problem better, and speed up my process.

The machine is a 11-20 metric? 50hz so probably European. The 50hz head is a higher rpm, 1500 I think. I am powering it with 60hz so it is spinning faster then that. I am considering a VFD to slow it down a bit.

 

[Milling man]

Be sure to try the magnetic separator. Cast iron, of course, is less magnetic than steel, but it is still magnetic at least somehow. Perhaps two magnetic separators in series.
Ideally, a belt filter with filter paper or cloth should be placed after magnetic separation.

 

[Hobby Shop]

I’m surprised the wheel doesn’t load up instantly with 120 grit on cast iron. Have you considered using a diamond wheel? The place I bought my machine from used a diamond wheel to grind carbide broaches and the finish was perfect.

There are 3 adjustment bolts to tilt the head. They tilted the head a little bit so only the leading edge of the wheel would cut and they didn’t get the traditional Blanchard swirl pattern. I have no idea how a diamond wheel would work on cast but it might be worth looking in to.

 

[swarfless]

I missed the 120 grit .. sounds like a recipe for disaster, virtually a pre-glazed wheel. Where are all the grinding gurus? I know nothing about Blanchard, precious little about the others, but fine grit & large contact area .. nah. Nah to diamond on iron too.

 

[EmGo]

There were (3) coolant tank set-ups that I have run:
1. straight tank under the machine a 'Bathtub" that you Hoe out.
2. An add on electric motor and drag chain system for the bathtub.
3. A different Hi-production set-up where the bathtub is kept empty, all coolant & swarf flows out the back into a multi level system of riffles, and a larger setting tank.

One step better is when it's pumped out of the catch tank to a separate tank with a filter material across the top. Coolant is dumped above the fllter, flows through into the tank, and feeds the coolant pump from there. Commercial ones have a motor drive to slowly change the filter media but on a small scale you could do it manually.

I would think a blanchard would like this, from the sheer amount of swarf they can make.

 

[DDoug]

One step better is when it's pumped out of the catch tank to a separate tank with a filter material across the top. Coolant is dumped above the fllter, flows through into the tank, and feeds the coolant pump from there. Commercial ones have a motor drive to slowly change the filter media but on a small scale you could do it manually.

I would think a blanchard would like this, from the sheer amount of swarf they can make.

If your going to quote me, take all of it:
"On a Campbell vertical grinder (I did not run) I saw an
add on hydrocone system, had (2) centrifuge cones, and a filter paper belt."

 

[EmGo]

If your going to quote me, take all of it:
"On a Campbell vertical grinder (I did not run) I saw an
add on hydrocone system, had (2) centrifuge cones, and a filter paper belt."

Ja, but that's a lot more complex than the simple travelling-paper ones. Didn't mean to infer you didn't know about more, just jumped to a simple easy-to-maintain system that he could either buy or make.

I wouldn't want to deal with those centrifuge things unless I was a pretty big shop ...

 

[Wiley QualiChem]

Are you using a coolant that is designed for grinding? Grinding requires coolant to carry the swarf away from the grind, but also allow settling/filtration. As simple as Blanchard grinding is, there are coolant designed for it. Keeps the stones clean, the swarf moving and the filtration functional.

 

[twoslowinwyo]

i hope this will help.
where i work we grind on large 600mm dia. cast iron plates with a hardness of 55-60Rc. we use Perkool 710AB for coolant at a 10% concentration level. we also use a bag type filter system. it goes from the pump to the filter then to the grinding wheel. we still have to shovel out the bottom of the tank once every two weeks. but the coolant stays nice and clean. before the filter we had the same problem of the wheel glazing. we get our wheels from Jowitt&Rodgers in Pennsylvania. the grinding wheel mix is. AX30F15DB1
if you need more help call Jim Hartley at Jowitt&Rodgers, they helped us out a lot.

 

[Blaser Swisslube]

Along with a magnetic separator like several other users have suggested, a bag filtration is another option.