Coolant add to the lathe

Machine Shop
#1

Yesterday, Sunday, I assisted Alford turn down a pair of slightly over diameter brake rotors on the clausing. (He wasn’t trained, so I did the turning) The coolant wouldn’t flow and it was found to be at a low level in the sump. We did some search on Talk to find that there was a recommendation of 5-10% of concentrated coolant to water. Mixed one pint of conc. to 14 pints of water to go to about 7%. Added a gallon to the lathe sump. The coolant flush was restored and the turning completed.

There doesn’t appear to be any indication on the dilution drum of the dilution ratio. Or on the instruction panel on the Zoro coolant container. The remainder, about a gallon, in the dilution bucket is about 7%. The lathe sump is only about half full now so if the dilution needs to be higher more concentrate can be added, and if the dilution should be lower there is room to cut in nearly in half with out over flowing it.

When the level of coolant solution drops over time, chances are good that some of that loss is by water evaporating, more than the additives; so, over time the concentration would rise. Probably not much of a problem as the dilution schedule is a trade off of getting the minimum desired properties with economy. But if we have an instrument for measuring the conc. we likely could conserve on the amount of coolant concentrate added in future adds.

Regards,

Bob

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#2

@TBJK We were making the premix at 10:1 ratio. But as Tim pointed out most evaporation is of the water. I think the 14:1 ratio is better. Need update marking on premix container.

5 gallons equals 45 oz, call it 48 or 3 pints, rest water
4 gallons equals 36 oz, call it 32 oz, quart and rest water
3 gallons equals 27 oz, call it 24 oz, pint and a half and rest water.
2 gallons equals 18 oz, call it 16 oz, pint and rest water
1 gallon equals 9 oz, call it 8 oz, 1 cup, rest water.
I’ll look for a plastics pitcher to mark concentrate so we get 7%. Fill with concentrate to level then add X number of pitchers of water. Will get a funnel so it’s easier to fill big container rather than in sink Maybe get a 2 gallon container for the premix; have 116-18 oz small bottle with concentrate, then add to container top off with water.

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#3

the pre-mix is located under the drill press and is marked. If the 5 gallon bucket is marked post on here and someone will mix some up.

#4

I’m thinking that we may need to add just water at this point. We need to check with a refractometer to see our percentage.

#5

good point. we get a LOT of evaporation on the HAAS as well and only need to add water.
The refracto is in the haas toolbox and I’d be happy to show anyone how it works. I’ll be there Tuesday and Thursday for sure.

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#6

Can someone please write “PRE-MIXED” on the bucket underneath the drill press? I was told during the class that there should be two buckets under the press, one concentrate and one pre-mixed, but only saw one of them Thursday night and it didn’t look like the green coolant. I see that its 10:1 or 14:1 now, so I’ll mix that if needed in the future. Anyone know what the sump capacity is off hand?

I’ll plan on adding pre-mix next time unless a refractometer has appeared and we’re over 10%.

#7

the other bucket was last seen by the cold saw although it may be empty. that is the bucket for the pre-mix. the one under the press is likely the concentrate.

#8

Bless you. I would have gone crazy looking for that bucket.

#9

The bucket did have pre-mix written on it in a couple spots. I know that because I wrote it.

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#10

I saw that “Pre-Mix” was written on the one drum, but perhaps, we should add the ratio to it. I’d go for a low side ratio (low concentrate) as not only does that extend the life of the concentrate bucket, but due to evaporation the concentration in the sump will rise with use.

The level of the sump can be viewed directly by removing a cover from the back side. If the level is down to about one quarter, the pumping does not occur. If the level is at least half, it will probably operate for a month. A month ago I added a gallon, so a gallon a month or so is the evaporation/splash out rate. Two gallons could have been added, but as I was unsure about the conc. I was adding, I left some empty volume to allow changing the ratio without incurring the inconvenience of draining some out.

It is probably timely to index a sample of the coolant to find the concentration that has built up over months of adds and evaporation. We might be surprised at how concentrated it has become. Might be time for a water only add!

#11

Maybe some Maker Elves can make a Full float indicator. The problem with filling is we don’t add as much as we could because we can’r see how full tank is. Same for Cold Cut Saw … the low indicator is easy: No Coolant Flow.

#12

Well. I have floats. An easy do.

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#13

Of course you do! What was I thinking? image

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#14

There’s two gallons of premix under the drill press. I also added two gallons to the lathe. Noticed that the chip pan doesn’t drain well. Probably why it all evaporates.

Also, I fixed the coolant post mount. It’s secure now.