First of all, doing flood coolant on my Lagun FTV-2 vertical mill (10x50 table) was pretty cheap and easy. There is a sump in the cast iron base and the pump, wiring switch and tubing inside the column was all in place. There is a 1/4 turn ball valve on the left of the column and a switch on the right. So all it took was the external flex piping, nozzles and fittings plus some coolant to get it going. The pump has a 60 watt 220v/440v 3 phase motor so I have to run my 220v rotary phase converter to run the pump, but that is no problem. For the record, I have only tried the Syn-Kool brand of synthetic coolant concentrate so far. I also bought a magnetic base, flex support, transparent. lexan shield to control splatter. Locally I bought about 4 feet of 3/4 inch automotive radiator hose to connect the table drain to the sump inlet.
My first expectation was that the milling cutter was going to sling coolant from one end of the shop to the other. Surprisingly, it was not so! It slings some but by placing the shield fairly close in front of the cutter very little gets on me and what gets on the machine mostly drains to the sump. some does get on the floor, but nothing like I had feared. A few quick swipes with the mop prevents any build up.
It would have been nice if someone had told me Murphy's first law of setup when using flood coolant. Namely, if any portion of the workpiece or setup extends beyond the edge of the table, even if it appears to go uphill, the coolant will follow it far enough to run off on the floor in a steady stream, (possibly into your shoe).
It seems that one of the more important reasons to use flood coolant has been utterly unmentioned, Swarf & Chip Control! I was pleasantly surprised to find that when using flood coolant that those nasty needles of fine swarf that are generated by cutting with the side of an end mill a. don't go flying anywhere near as far as they used to. Most of them are caught in the coolant and drop promptly on the table and are swept away via the T-slots, and afterward, those left on the table adhere slightly to it instead of making the skin of your fingers look like they tangled with a micro-porcupine. My expectation of how far the coolant would be splattered was based on how far the mill would throw chips, but with flood coolant the flinging distance is greatly reduced.
One of my great fears was that since the coolant was more water than additive, that surely I was going to have rusting problems. Not so! The additive remains on the machine surfaces after the water has evaporated out of it. But then I thought, HORRORS, with that sump full of coolant, there will be 100% humidity inside the sump and column. It is going to rust like crazy in there. 2 months later, not a hint of rust! If water can evaporate out of the coolant, surely it will condense on the metal farther up, but no! Either that red paint in there is something very special or that coolant does something pretty tricky.
OK! You guys did warn me that my table better have some grooves along the edges to keep coolant from running off the edges. Well it does, and they do work, but unfortunately the cross grooves at the ends of the tables do not entirely interdict them and coolant was dribbling steadily off the ends of the table. It seems that the lead screw brackets nicely block the t slots but not the side grooves. Well a little bit of plumbers solid epoxy dams quickly fixed that after I cleaned the oily film out of the grooves.
One of the things that was a great motivation to me to try flood coolant were some ruined carbide end mills. It seems that when the mill was breaking out of the work piece at the end of a cut, that when the remaining metal became thin, it could not dissipate heat like in the rest of the cut. So suddenly, I would discover that the feed rate was not enough and and the thin piece of metal would turn red and the heat of the metal would thermal shock the cutting edges of the cutter. I was expecting the flood coolant to prevent this, but hey! the work piece is not even warm. It is actually cold! So is the cutter. Well I guess that in addition to saving the carbide end mills, it will save me a few "owies" when I am in a hurry to remove the work piece or change the cutter.
It would have been nice if someone had told me to get a "y" fitting so that I can cool the cutter from two directions at once. I can now see how convenient that is, especially when making cuts in both directions. Actually I could use a few illustrations about how to supply coolant to various types of cuts. So if some of you who are more experienced would get your cameras out the next time you have set the nozzles up in yet another nifty way, it would provide a valuable educational experience.
Tramp oil was another thing I knew might be a problem. However I did not really suspect what the main source was going to be. In fact I hardly expected any problem at all. But there is a slight one. Most of my tramp oil seems to come from the one-shot-oiler that lubricates the ways. The flood coolant that gets onto the top of the knee seems to rinse it down into the sump. There may be a little that drips off of the quill and spindle but that has to be way less, and an occasional drop or two when I tap a hole. However I did not want to invest in a fancy expensive skimmer until I had assessed a lot of other things about flood coolant. As it turns out, it so far has been satisfactory to open the access to the sump and just lay a paper towel on top of the coolant and then pick it up and throw it away. The oil is readily picked up by the towel. Now if there is a substitute for way oil that I can use in the one shot oiler, the problem will be reduced even further.
I was warned about stinking rancid sumps and I have even encountered a few in other shops, but so far, no problem! I guess that the synthetics can live up to the claims about little or no such trouble.
Evaporation has been a little bit of a problem. My basement is now in the low humidity part of the year and the sump level went down noticeably during a week or so when I did not use the mill, and it suddenly dawned on me why that was. I ran the pump and added some water to the mix and had no problem getting it to combine nicely even though the bottle warns "O.I.L. = Oil In Last". I guess I need some cost effective way to judge when the concentration is getting off, and if any of you guys have any practical hints to offer that do not require me to buy an expensive measuring apparatus, I will be most appreciative.
One little problem that proved to be annoying is those Loc-Line or Snap-Flow flexible pipe segments and fittings that supposedly can be put together by hand. Well, yes they can, provided your hands and the segments are clean and dry and you have strong fingers and not too many of them to put together and you don't mind, knocking the piping out of line. They really do need those assembly pliers they sell, or something like that. Anyway I have ordered a pair, and I hope they work better than doing it by hand. Well, hand assembly was a pain but at least doable for an initial set up to see if I wanted to follow through with flood coolant.
If mess was what I was most concerned about and that has been only minor if at all, there is a closely related benefit I did not expect. When I was using cutting oil to help with the machining the chips were quite oily or they picked up oil when they landed on the machine ways. As part of cleanup I had tried vacuuming them off the machine with my shop-vac. But that little bit of oil on the chips plus what ever got sucked up off the machine just made a mess out of the shop-vac hose. It just softened the plastic hose material to the point of uselessness Well the coolant I am using does not seem to bother the hose near as much if at all. The chips seem to be a bit adherent to the machine horizontal surfaces if I don't clean it up until the coolant has dried, but the coolant has flushed most of the chips on the machine into the cross grooves at the end of the table and the rest are easily swept off of the machine surfaces with some cheap bristle paint brushes I keep around for machine clean up.
I think you can see from the general tone of this, that I am mostly quite pleased with flood coolant so far. The negatives have been less problem than I expected and there are ways to offset those problems and there have been unexpected surprise advantages. Maybe I am just lucky or maybe I am a Pollyanna but I don't think so. I am sure I will have more "adventures" and probably some of them will be "mis-adventures", but I hope this will encourage other beginners to seriously consider trying flood coolant. It has been far less messy or troublesome than I thought it would be and so far it has been very beneficial.
Granted, I got off easy on cost because most of the system was present and operational on my mill already and that may not be so for others. My successes with this to date have got me to wondering now if I should consider adding flood coolant to my lathe. Of course I might find that a lathe chuck is a far superior coolant flinger when compared to a milling cutter...
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