Surface grinder coolant system

[bladegrinder]

Last week REK knives posted a short video clip of his surface grinder with coolant system running, I contacted him and he was nice enough to help in getting me started on one for mine...so thanks REK knives. I'm no machinist so it helped to have someone with the same machine with a set up I was interested in.

Looking at my machine I couldn't quite figure out where the fluid troughs and drains were.

While I'm aware this isn't a common machine found in knifemakers shops it is found in lots of them. I have a small Sanford grinder but rarely used it because it lacked power and was kind of limited to what you could do with it. after I built my new shop and before I moved I was lucky and found a 6 x 12 Harig.
I use it mainly on folder blades and backbars, and while it was a huge step up and did nice finishes, on thin blades I could only take light passes or I would get lite burn marks or even slight warping.
After seeing REKs video with the same machine I said I got to do that. with this coolant system I can take heavier passes and the finish is absolutely better than running this thing dry. for those of you that have a surface grinder you really need to run a coolant system, the results were remarkable to me.
The whole shebang cost me about $80.00 including the fluid. ...that's a piece of stainless Damascus on the chuck.

 

[REK Knives]

That looks great!! So how does it work for you when you move the table back and forth, is the bucket on rollers?

 

[bladegrinder]

No, it sits on a milk crate so the cheap pump I bought has enough lift. Where the drain is connected to the machine with a galvanized nipple is a stationary part of the machine. It’s a trough that sits below the table. Right behind the Chuck there’s a drain hole… that was plugged, I couldn’t even see it, I cleaned that out. So as the table moves back and forth the drain hole is always over the trough.

 

[REK Knives]

Ahhhh yeah now that I think about it that's how mine works too!

 

[MTBob]

On the subject of coolant spray methods, FWIW,
For years I've used this 4x36 wet/dry grinder for general metal work (though not so much for knife grinding). The problem I've had is routine plugging of the spray head mounted just below the platen, since the grinding crud used to flow down into the sump and was then picked up by the spray pump.
So I modified the water cycle to include a settling tank for the crud, which then delivers clean water to the pump & spray nozzle.
In the photo (A) is the settling tank that takes the water and crud directly from the grinder. Internal to the tank is a baffle that clean water flows over. The clean water then flows down into the clean water tank (B) that holds the spray pump. So, essentially this is a 2 stage settling pond. After this photo was taken the galvanized settling tank sprung a leak and has now been replaced with a plastic tank.
Though I don't have a surface grinder, I suspect a similar water / crud problem could occur.

 

[bladegrinder]

I was thinking of doing something similar to that but instead I put the drain pipe into about a quart size filter bag that’s rated at 100 micron. It has quite a bit of stuff in it now but it’s mostly run off of what was all over the machine from the past. It seems to be working though and now I’m thinking of putting the pump into another one.