Originally Posted by ken snyder
I flood with the same coolant I mist with. Kool Mist 77. It isn't the best stuff in the world for flooding because it needs to be changed often. But the stuff that doesnt need to be changed so often starts stinking so bad that it gets changed even more often. It yields a fantastic surface but does require a very high equipment maintenance schedule to prevent rusting. - surface is what it is all about not tool life or just walking away from a machine and being able to let it set!. For interupted cutting and threading I use Beeswax
I remember when we used soluble oils for coolant and comming in on Monday morning with coolant tanks spoiled. Then we installed an airration system in a couple tanks, and made a big difference. Then somebody brought in a tank of Raw Trim CE. We had problems with it at first, but found out that the guys were not mixing the stuff right. Once we got that lesson learned it was OK. Later Howghton made them somekind deal, and this stuff was junk. It would eat the Viton oil seals up, and would also etch steel surfaces. Made a lot of money that year repairing the damage.
The idea of going to the synthetic coolants was to get a cleaner part with longer tool life. This was a very low volume operation, and on some jobs they reamed about 50 holes a month. which added another problem here and there. Bought gauges to check out the quality of the coolants in the machines (every operator got one). That alone made a huge difference. We did a lot of experimenting with Tim and another brand that's name escapes me right now. Then somebody made the mistake of putting Trim in an 80 ton broach!! By the time we found it we figured that the broach bars were junk (about $15K), but the broach operation just working like clock work. To be exact the parts came out better. Lesson learned there was that the coolant was able to withstand extreme cutting pressures. Broach bars lasted a little longer, and when reground cleaned up easier. The one place we didn't like it was for thread grinding. Oil just worked better (Excello thread grinders) with the red wheels we were using. But when we ground threads on a Studer the standard coolants worked better (not Trim but a specialized grinder coolant that was water based). We also found that oil based coolants worked better in gear grinding and gear cutting operations in most cases. But for turning and machine centers the water based stuff was the best. Still get aluminum oxide issues when cutting aluminum, but you'll get that with anything. Most of our machine centers use Tico-Way bearings, and these are extremely critical things. Are easy to pit and depend on line contact at a preload. Never an issue, but we still changed them out every 24 months on high output operations due to the aluminum oxide issues. Not bad for an operation that runs 24 / 7.
But as I said before the most accurate reaming we ever did was with strait up mineral seal that had about 3% Mobile DTE 24 added to it for our own peace of mind. Finish looks like it was honed and parts were very accurate. One operation we did had a four step bore that went from about 25mm down to 10mm. The bore was about 250mm long. The tolarence was .0004" compound error, and also include bore diameters and over all length. That ment that all the error added up could not exceed .0004" TIR. Used Mapol reamers and mineral seal running at close to 100 psi. Material was nodular iron in this case. Tool life was very good, and when the accuracey went south we changed spindle bearings.