[rcazwillis]

I am putting together a plan for flood coolant on my bench top mill (HF Big Red). What kind of pump should I use? I have seen a few nice setups, but no references to pumps. I am thinking low HP sump pump will do the trick. I think it needs to be something that is designed to handle trash.

I plan on returning the fluid to a tank below the bench. The container will have a fine mesh screen that the fluid goes through to filter the larger pieces. Should I filter it again before going to the pump? If so, what kind of low cost solutions are available.

Last question, should I raise the pump up off the floor of the tank to prevent sucking up the larger pieces that float to the bottom?

Any tips or advice from past experiences is appreciated. Thanks in advance.

[2muchstuff]

Check out http://mcmaster.com On page 286 under coolant pumps, item 4336K51 is a nice 1/15 hp coolant recirculating pump. They have a decent size intake and discharge opening that will allow the smaller pieces to pass thru. Afilter screen is a good idea but you will not enough flow to wash down the big stuff. Most times they just drain right back into the tank. You do want to keep the pump intake off of the bottom of the tank so you don't suck up the shavings. Let them collect in the tank bottom till next fluid change.

[rcazwillis]

What about something like 4193K11, page 265? $89, thermal overload protection, self priming, 3/4" intake & discharge, flows 5 gpm.

Would this not work with a water based synthetic coolant?

[2muchstuff]

That pump will work with water based collants but my concern is with th impeller. It doesn't say whether it is a centrifigal or a rubber type that rides against the housing, like one of those drill pumps. If it is a centrifigal then it is no problem, small particals will pass thru with no problem. If it is an impeller type then the small particals will wear out the rubber impeller. With the amount of lift that it has, self priming to that height, I would assume that it has a rubber impeller. I haven't looked for one yet but what about a parts washer pump from a tank mounted parts washer.

[rcazwillis]

Harbor Freight $49 or $99. I had the same thought. They have to be built to handle junk in the fluid. Thanks for the help. I will post results when it is done.

[2muchstuff]

Just don't use a magnetic drive pump. Magnets and steel shavings can clog things up quickly.