Minimum quantity lubrication for grinders? Kool mist alternative?

[aarongough]

Hey guys!
I've seen lots of talk about wet belt grinders here and elsewhere for a long time. I think they're a good idea overall but there's 2 main issues that strike me with them:

1) Mess, lots of water sprayed everywhere generally
2) Most belts aren't designed to be run wet so you either have to limit your choice or end up with pretzel belts all the time

It's been nagging at the back of my brain that the machinist guys have a concept they're introducing called 'Minimum Quantity Lubrication' (MQL) (moreso in Europe than the US AFAIK) which is meant to replace flood cooling in a lot of application. Basically the concept is that you apply just enough coolant to the tool/workpiece that you'll evaporate all the coolant during the machining operation... The tool and workpiece are left cool and there's no messy residue or puddles of coolant everywhere.

I have been wondering the same concept might be applicable to use on our belt grinders!

It would be nice to have a constant cooling effect so that we're keeping the heat out of the steel (and keeping stuff like G10 cool). However it seems that it's a little pricy to get into the game. A unit like the 'kool mist' is fairly inexpensive (~$100) but from what I've seen the 'fog' that it creates will tend to only partially stick to the belt, the rest of the fog continues on to your grinder and the surroundings... The cheapest MQL style system that I've seen so far is the 'FogBuster' which runs about $310, that's a bit of a leap given that I have no idea whether it will work.

So guys, any thoughts? Anyone have experience with these kinds of systems? What other methods (besides the dip bucket) do you use to cool your blades?

Thanks!
-Aaron

 

[Karburized]

My setup is super ghetto, but it works great. I'm using an old touch-up spray gun i had lying around. at 10 or so psi, the spray pattern is heavy enough that it will keep the temps down and cool the blade very quickly as you finish a pass, won't fog up the work area, and just light enough that I don't have big puddles of water. At worst I'm using 1 gallon of water per hardened 8" knife for primary beveling operations.

You are going to get a little mess, but it will be in a relatively contained area and there will be significantly less airborne dust. If you are doing long and thin chef's knives the amount of time you save by not dipping adds up. Even more so if you are doing jig-mounted grinds. I would say I've nearly doubled my productivity since I've started wet grinding.

In my experience, The 120 grit Nortons Blaze will pretzel. The 60 Norton Blaze, 60 3M Cubitron 2, all of my 3M Gators, and Scotch Brites do not.

 

[aarongough]

My setup is super ghetto, but it works great. I'm using an old touch-up spray gun i had lying around. at 10 or so psi, the spray pattern is heavy enough that it will keep the temps down and cool the blade very quickly as you finish a pass, won't fog up the work area, and just light enough that I don't have big puddles of water. At worst I'm using 1 gallon of water per hardened 8" knife for primary beveling operations.

You are going to get a little mess, but it will be in a relatively contained area and there will be significantly less airborne dust. If you are doing long and thin chef's knives the amount of time you save by not dipping adds up. Even more so if you are doing jig-mounted grinds. I would say I've nearly doubled my productivity since I've started wet grinding.

In my experience, The 120 grit Nortons Blaze will pretzel. The 60 Norton Blaze, 60 3M Cubitron 2, all of my 3M Gators, and Scotch Brites do not.

Thanks for the reply mate! I had wondered about using an airbrush or HVLP gun for the same purpose, you can get some pretty cheap gravity feed guns out there now! Good to know it works!

 

[Brett Bennett]

You might take a look at equipment used in lapidary work. The ones I've used worked with a drip system. You could make one pretty easy (think IV) and install a valve if you wanted to get fancy.

 

[synthesist]

@Karburized..........................

Please we need pictures. You did get me thinking here tho. I can imagine a 5 gallon bucket with an HVLP sprayer and a foot pedal controlling it as a way to really save some time doing this. Kinda like a water fogger blast cabinet.

Isn't that how they make snow at ski resorts?

Corey

 

[Daniel Fairly Knives]

Check out the Sofa King Cool Grinder... there is a video somewhere out there with the cooling system explained.

 

[Overmountain]

Little machine shop has a kool mist without a tank for about $120 I think. Way cheaper than my HVLP gun...

-Eric

 

[KUNTZI66]

Looky here, might be an option for you.
http://www.bladeforums.com/forums/showthread.php/1023143-Flat-platens-radius-platens-water-cooled-platen-chillers

 

[aarongough]

You might take a look at equipment used in lapidary work. The ones I've used worked with a drip system. You could make one pretty easy (think IV) and install a valve if you wanted to get fancy.

I've seen a few similar setups with drips going onto the belt... They just seemed messy as you're applying big water droplets that don't get the chance to spread out, and instead get thrown off at the first turn of the belt. The reason I was interested in the MQL style systems is because they apply a finer 'splatter' of tiny droplets to a broader area and I think if you tune it right you might be able to get almost zero coolant thrown off the belt...

Check out the Sofa King Cool Grinder... there is a video somewhere out there with the cooling system explained.

Yeah I saw the videos of Mick demonstrating the grinder yesterday during my google searches. Looks like it works well, just pretty messy... I'll deal with the mess if I have to, I'm just hoping for something that will let me avoid it!

Little machine shop has a kool mist without a tank for about $120 I think. Way cheaper than my HVLP gun...

-Eric

There are actually a bunch of really inexpensive chinese made HVLP guns floating around on places like amazon now. I got mine straight from Cerakote with my Cerakote starter kit and it was only $40. It works extremely well, there were guys in my shop that have been spraying with nice siphon guns for quite a while and they were really impressed by how well that $40 gun worked, even when comparing it against their much more expensive guns! They have similar models with 0.8mm tips on amazon for around $20, so there's definitely a low cost option there...

Looky here, might be an option for you.
http://www.bladeforums.com/forums/showthread.php/1023143-Flat-platens-radius-platens-water-cooled-platen-chillers

Those platen chillers are awesome! I was planning on getting one of those in addition to whatever spray system so that the whole deal runs as cooly as possible.

 

[PT Doc]

Noga has similar coolant applicators. Enco carries as line with a wide applicator tip. Noga has the ability the control the air and coolant input separately so that should help with getting the coolant light enough and spread out.

 

[aarongough]

Noga has similar coolant applicators. Enco carries as line with a wide applicator tip. Noga has the ability the control the air and coolant input separately so that should help with getting the coolant light enough and spread out.

Thanks Doc! I'll check them out!