Does Motor Oil Corrode Brass?

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SteveM
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Re: Does Motor Oil Corrode Brass?

Post by SteveM »

warmstrong1955 wrote: Wed Feb 21, 2018 2:23 pmIf you had ever seen what happens to an engine, that was using non-detergent oil, and was changed to detergent oil, you would be a believer. The detergent, does just like it's name, and will clean out all that sludge settled in the pan, the valley and elsewhere in the block, churn it up, and send all that nasty stuff, including metal, thru the bearings, and everything else for that matter.
The oil change interval on a Ford Model A is 500 miles, and every 2,000 miles you have to pull the pan and scrape out the sludge.

Steve
spro
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Re: Does Motor Oil Corrode Brass?

Post by spro »

Yes Steve. This information fits together although it covers a long time span. The sludge was the unburned carbon particles which had to settle somewhere. I thank all the contributors to this discussion.
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wlw-19958
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Re: Does Motor Oil Corrode Brass?

Post by wlw-19958 »

Hi There,
SteveM wrote: Wed Feb 21, 2018 5:17 pmThe oil change interval on a Ford Model A is 500 miles, and every 2,000 miles you have to pull the pan and scrape out the sludge.
And one may need to peel a shim off the bearing caps
if a knock developed.
spro wrote: Wed Feb 21, 2018 6:31 pm Yes Steve. This information fits together although it covers a long time span. The sludge was the unburned carbon particles which had to settle somewhere. I thank all the contributors to this discussion.
And back in those days, lead deposits would be in
there too.

Good Luck!
-Blue Chips-
Webb
spro
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Re: Does Motor Oil Corrode Brass?

Post by spro »

Great point Webb. They shipped it out to the grand Valleys in some cases. Don't want to get there from here. Just want to say something about that but I won't.
Ironman1
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Re: Does Motor Oil Corrode Brass?

Post by Ironman1 »

From ShopFloorTalk forum:
From an oil chemist
I am betting that the gear oil you used is
a GL-4 or GL-5 gear oil, those are EP gear oils using a sulfur phosphorus
EP agent that will eat up than nice bronze bull gear in your worm gear set.
The S-P EP additive is not compatible with any copper alloys. Bronze and
brass are not going to last.

I would recommend your replace it with one of the following:
This covers all options:
Mobil SHC Gear 460

This is a good lubricant, despite the poor marketing:
Super Lube 54432 Synthetic Gear Oil ISO 460, 1 quart Bottle, Translucent: Amazon.com: Industrial & Scientific

This will work but will not be cheap:
https://www.mobil.com/English-US/Ind...le-Series-Oils
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Self education will make you a fortune.- Jim Rohn

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John Hasler
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Re: Does Motor Oil Corrode Brass?

Post by John Hasler »

Ironman1 wrote: Wed Feb 21, 2018 11:24 pm From ShopFloorTalk forum:
From an oil chemist
I am betting that the gear oil you used is
a GL-4 or GL-5 gear oil, those are EP gear oils using a sulfur phosphorus
EP agent that will eat up than nice bronze bull gear in your worm gear set.
The S-P EP additive is not compatible with any copper alloys. Bronze and
brass are not going to last.

I would recommend your replace it with one of the following:
This covers all options:
Mobil SHC Gear 460

This is a good lubricant, despite the poor marketing:
Super Lube 54432 Synthetic Gear Oil ISO 460, 1 quart Bottle, Translucent: Amazon.com: Industrial & Scientific

This will work but will not be cheap:
https://www.mobil.com/English-US/Ind...le-Series-Oils
For every comment like that I can find another equally authoritative one asserting that modern automobile lubricants no longer attack brass. Thus my tests. This says nothing about the various racing/off-road/industrial EP oils not regulated by the EPA, though.
Ironman1
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Re: Does Motor Oil Corrode Brass?

Post by Ironman1 »

True enough. But after opening my worm drive and finding it lubricated with chinese Yak fat, and the gear faces dry, I thought gear oil would be a good thing. There are gear lubes out there that work and are safe on brass. I want something a bit thicker than motor oil for my saw.
Formal education will make you a living;
Self education will make you a fortune.- Jim Rohn

"Opportunity is missed by most people because it is dressed in overalls and looks like work." Thomas Edison
John Hasler
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Re: Does Motor Oil Corrode Brass?

Post by John Hasler »

Ironman1 wrote: Thu Feb 22, 2018 9:11 am True enough. But after opening my worm drive and finding it lubricated with chinese Yak fat, and the gear faces dry, I thought gear oil would be a good thing. There are gear lubes out there that work and are safe on brass. I want something a bit thicker than motor oil for my saw.
That's why I intend to compound my oil using mostly Lucas heavy engine oil additive. It's pure hydrocarbons and has an ISO viscosity of about 1500. My next step is to measure the actual 40C viscosity of the Lucas and the 5W20 synthetic so that I can compute the correct ratio to get the viscosity I want (I'm aiming for ISO 680). The synthetic will improve lubricity and provide additives which I want as long as they don't attack brass. I have spur gears in there as well as the worm.

I'll be able to use up the leftover Lucas in my tractors. Or maybe I should inject it into my joints. Some of them seem to be in need of a lubricity improver.
spro
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Re: Does Motor Oil Corrode Brass?

Post by spro »

It is interesting how different lubes are more appropriate over time of the machines. We know the originals.
Glenn Brooks
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Re: Does Motor Oil Corrode Brass?

Post by Glenn Brooks »

One other thing to consider, if you intend to use modern GL - 5 gear lube is that these extreme pressure oils are designed to lubricate modern hypoid gear systems, not older non -hypoid low pressure gear trains. The EP oils have a very small molecular structure that does not coat low pressure gears, such as found in older manual machine tools. The oil is to slippery, and it runs off the gear bearing surfaces. Hence it does not coat the gears and causes excessive wear due to poor Lubrication in low pressure gear boxes.
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John Hasler
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Re: Does Motor Oil Corrode Brass?

Post by John Hasler »

I intend to use a mixture of Lucas engine oil additive which is essentially ISO 1500 mineral oil and enough GL-5 synthetic to bring the viscosity down to about 680. The gearbox contains a 6:1 worm and a 4:1 spur gear. The worm will be fully immersed and the spur gear point of contact will also be immersed. The spur gear efficiency will be suboptimal with this heavy lubricant but I anticipate no wear problems with it.

The Lucas additive is interesting stuff. It is all mineral but there is some amazingly sticky (but still slippery) stuff in there. After cleaning the equipment I used to make some measurements I'm quite sure that it running off bearing surfaces is not going to be a problem.
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