I find metal fabrication fascinating and baffling in approximately equal measure. I’ve been watching a lot of metal fabrication/machinist/tool-porn videos on YouTube lately (AvE and This Old Tony are my personal favorites, but I can watch just about any of them) and I realized I’m so ignorant about how things work that I can’t even do a reasonable Google search.
My current query is: I know that in some machining processes it is necessary or advisable to use a lubricant or coolant. And I’ve seen that this is sometimes handled by a sort of dispenser that covers the part and tool with the liquid in question. What I don’t understand is what happens to all this coolant? I recognize that this answer is probably very different depending upon how much money you have to throw at a problem. I presume you don’t generally just let it pour all over your shop-floor. Are tools which generally need to use coolant built into catch-basins that drain the used coolant?
Also, this whole process seems somewhat wasteful…is coolant for machining super inexpensive? Can the coolant be collected and reused or otherwise recycled? What of the environmental impact of this coolant (which I recognize is pretty small potatoes in the face of everything that needs to happen to enable metal fabrication).
And one last thing: is there some “for dummies” level of site/videos/books which will take me step by step through the different processes of fabricating things? I’ve noticed that even when This Old Tony is apologizing for being so simplistic he still often loses me.
I am not a machinist, but I was a machinist’s helper for a couple years. Knowing which lubricants to use for certain tasks is part of being a machinist. Back in the old days, for example, we kept jars of mutton tallow to use when threading or reaming acrylic (Plexiglas).
I just retired from an industry where field technicians often had to drill through mild steel (e.g., door frames). I was incredulous at how many of them tried to do this without any lubrication whatsoever on the drill bit. They would ruin good quality drill bits and waste much of their time when they could have done something quite simple to reduce the problem. (Just get a little engine oil from the dipstick of your car, for example.)
Good on you for wanting to learn more! I enjoyed learning at the feet of good machinists much more than anything else I’ve done in my career.
Oh, yeah…there are catch tanks or basins to recover the lubricant or coolant. Government agencies frown on doing anything else.
It’s like a fountain. It drains into a reservoir to be pumped back out of the nozzles. No idea how much it costs though.
I used a water-based coolant (spray system) for my desktop mill.
It was a concentrate, and diluted something like 16:1 with water. I just collected it and dumped it (it was biodegradable), but big machines can collect, filter, and re-use their coolant, which is usually “flooded” onto the part.
Lubricant or coolant?
In videos made by Mr. Pete (Tubacain) or Clicksprick et. al (and even AvE as well), they just brush on the lubricant on the drill, mill bit, etc. as they start work on the piece (and sometimes during machining), usually ending up with a pile of somewhat oily chips/cuttings which sometimes they brush off/clean up on video. I do this as well (although not as elegantly)
Continuous coolant streams for drilling/cutting, that’s a bit different system.
I worked in an industrial machining shop which turned out automotive and trucking components - hubs, spindles, brake shoes & calipers. The machines all had large catch basins built into the base, picture something the size of a large kiddie pool. Integral to these were a screen filter system, a few walls for settling, and some type of conveyor set up for chip removal. We had water based coolant and rarely changed or added coolant as the water section would evaporate and mostly we had to replace that. We also added algaecide and biocide treatments just like a pool to keep the bugs from growing in it. When we needed to drain or too much carbon built up, we shipped it out for recycling. The coolant was sprayed by fancy sump pumps through the machine to flood the parts. This was all integral to the machine design and wasn’t just something added at the end.
My best friend from high school OTOH has been a small one man machine shop since then. He makes small custom ordered components. Think of things like the knurled knobs on a filing cabinet or the shiny silvery parts of your dentist’s chair or exam light. He does stuff like that. His lathes and mills are more of the size you’re thinking. Even those have a built in catch basin with a small pump to circulate. The portable stuff that you have to add the lube, you need to clean up from the floor or machine. The maintenance shop I work in, we typically throw shop rags down to catch it or maybe some oil dry.
That’s really production work kind of stuff. For most home shop work just a bit of oil from an oil can, or some WD 40 (for aluminum) will get the job done.
The stuff you see pouring over everything is typically soluble oil, mixed with water, in a reservoir, circulating like a fountain. The T-slots in a milling machine will typically have a trough at one end that has a drain plug that can be hooked up with such a coolant system. Lathes have a trough / chip tray under the lathe bed. Horizontal bandsaws have a trough under the saw kerf.
For home shop work, it is only really needed if you are setting up a CNC shop–the speeds and feeds used for all of that computer guided machining demands flood cooling.
In fact, it is not unusual to run carbide tooling dry when doing manual machining. You can do so on cast iron or brass without much trouble, though aluminum tends to stick to things, so a bit of WD helps.
ETA: You can go nuts with this kind of stuff, and there are lubricants and coolants of every variety for various situations. I just go with a small container of chainsaw bar oil and a brush, or WD for the aluminum.