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loose nut
01-01-2010, 10:35 PM
My RF-45 type mill came with the usual black gunk that the Chinese think is oil, so I replaced it with new.

Specs called for ISO-68, I put in the good stuff, Mobil DTE heavy medium and now it foams.

!. What causes foaming.

2. does it cause damage, I'm assuming the answer is yes, probably it doesn't do the job in this condition???

3. best solution?? I could put in an anti-foaming agent, different oil, yes or no.

Some time ago there was a discussion on the merits of additives to make the oil stick to the gears better. I can't remember the conclusion, is it a good idea and does it alter the ability of the oil to function properly.

Thanks in a advance for any help you can give.

Carld
01-01-2010, 10:49 PM
I am not real sure about this but I think there is two versions of the ISO68 oil one will foam and the other is non foaming.

The tractor guys have this problem every now and then getting the wrong oil.

Ken_Shea
01-01-2010, 11:02 PM
Does it foam bad, or maybe that should be does it foam good????
My suspect is that it makes no difference in lubrication, can almost visualize it helping when it foams up into areas that may not otherwise be lubed, still don't like the thought of it.

Black_Moons
01-01-2010, 11:56 PM
Foam ruins 'plain' bearings, IE where you just have a bronze bushing and a rod in it. air gets into the bearing and they relie on oil being uncompressable to support the shaft.

That said you may not have plane bearings.. but I suspect there could be some in your gear train, so best to check (with someone who knows)

On the plus side, run it for a few mins untill it foams up real good before draining it for new oil. This will help suspend as much sluge and possable and get it drained out with the new oil change.
My first oil change on my mill after the chinese crude oil was STILL black within days of use as stuff that settled out settled back into the oil
my second oil change is still nice and clear. I can actualy see way into the oil sight. So you don't have to think of all that oil as 'wasted' but more as 'used to clean'

Also, is it foam or just little bubbles?
my IH mill generates tons of bubbles in the oil, but apparently those are not so much foaming oil and just a result of how violently it hits the oil with its gears. At least this is what I was told when I asked about it..

oldtiffie
01-02-2010, 01:54 AM
My RF-45 type mill came with the usual black gunk that the Chinese think is oil, so I replaced it with new.

Specs called for ISO-68, I put in the good stuff, Mobil DTE heavy medium and now it foams.

!. What causes foaming.

2. does it cause damage, I'm assuming the answer is yes, probably it doesn't do the job in this condition???

3. best solution?? I could put in an anti-foaming agent, different oil, yes or no.

Some time ago there was a discussion on the merits of additives to make the oil stick to the gears better. I can't remember the conclusion, is it a good idea and does it alter the ability of the oil to function properly.

Thanks in a advance for any help you can give.

Hi LN.

I use this in my mills ad lathe gear-boxes.

http://i200.photobucket.com/albums/aa294/oldtiffie/Lubrication/Machine_lub_oil1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Lubrication/Machine_lub_oil2.jpg
No problems - was recommenced from/by the firm I bought my stuff from.

I use it everywhere in the shop where oil lubrication is required.

Mark McGrath
01-02-2010, 05:26 AM
ISO 68 is only a grade.You still have to select the type of oil.You can have ISO 68 in slideway,hydraulic,gear,compressor and a load of other types all with different attributes.
I would have gone for gear or hydraulic oils as both have anti-foaming and anti-wear additives.
Mark.

loose nut
01-02-2010, 10:40 AM
Also, is it foam or just little bubbles?
my IH mill generates tons of bubbles in the oil, but apparently those are not so much foaming oil and just a result of how violently it hits the oil with its gears. .


Well it looks like a bubble bath, I cant say for sure if that is bubbles or foaming

Mark, the Mobil dte is a high quality hydraulic oil

I put the same oil in my lathes geared headstock and saddle and neither of those foam or bubble.

Some people have put things like STP or tackifiers in with their oil, any thoughts on that.

PeteM
01-02-2010, 01:11 PM
Any chance it's filled a bit above the fill line?

loose nut
01-02-2010, 03:15 PM
No, it has a "bullseye" to check the level with and it is in the right spot.