STP as a general lube?

Apart from high viscosity, it brings ZDDP

From the MSDS it doesn't look as though it has any other additives (these would normally "show up" on the sheet).

ZDDP is an anti-wear additive: the following lifted from Imperial College (London) who know about this sort of thing.

"Zinc dialkyldithiophosphates (ZDDPs) are the most successful lubricant additives ever invented. They were introduced over 60 years ago, have been in continuous use ever since and are still being employed in all current engine oils. During the last decade however, concern about the impact of phosphorus oxides on the exhaust after-treatment catalyst, especially its ability to reduce NOx and particulate emission, has necessitated a progressive reduction in the permitted concentration of this additive. Parallel to this there is also a tendency for oil drain intervals to be extended, which has resulted in a general increase in the level of dispersants employed in engine oils. Unfortunately, some nitrogen-based dispersants used in engine oil formulation are antagonistic to ZDDP".

In the UK power industry it is sometimes used when installing steam turbines. This involves lowering various shafts into half-bearings and twiddling them to align couplings, etc. The high viscosity means it doesn't drain away too quickly. The oil companies generally don't approve in case its additives interfere with "their" additives.

It looks fairly safe to me for your applications, but you should always be aware that some oil additives (e.g. EP additives) can cause corrosion of copper-based bearings, and if you mix different types of oil especially from different manufacturers the additives can "fight" (though I believe this is rare).

It's well marketed so probably expensive for what it is. But if you are using it in modest quantities convenience probably counts.

Way back when, we used STP to install press-fit bearings. Over a period of a day or so, the STP would get squeezed out of the joint, You could then press it apart and find no trace of the lubricant. This was a good thing for this application, but it would suggest that you wouldn't want to use STP in high pressure applications.

On Fri, 26 Feb 2010 04:02:49 -0500, the infamous "Buerste" scrawled the following:

If you use STP, you'll have to add oil to it for it to be considered a lube. I warned a shadetree mechanic about spinning a bearing when I saw him wiping his fresh rod and DIPPING his main bearings in the crap. Since I was just attending UTI and a punk 17 y/o kid, he didn't listen until 4 days later, when the recipient called from Nebraska...with a spun bearing. I think STP's owners saw enough of those to finally start adding actual _lubricants_ to the can, but I'd make sure if I were you. This was my experience in 1972.

Googling msds stp: The Clorox Company. No shit! Owns 409, Glad, GreenWorks, Liquid Plumr, Tiles, SOS, PineSol, and ArmorAll (who owns STP). Amazing. OK, they've totally reformulated it since then. It's mostly mineral oil now.

STP, I learned back then, clumps oil molecules so they don't run off the bearing surfaces when it's sitting overnight, keeping the engine from wearing and making things much more slick. I switched to Slick 50 when it came out but haven't used any additives for a couple decades.

STP reminded me of getting honey on my hands way back when. Does it still do that with the new formulation? Sticky, never seems to quite wipe off?

-- "Politics is the art of looking for trouble, finding it whether it exists or not, diagnosing it incorrectly, and applying the wrong remedy." -- Ernest Benn

=A0 =A0 =A0 =A0-- Ernest Benn

Just to add fuel to the fire: WAY back when, we owned a 1959 Austin Healey Sprite. Used a 4 cylinder Austin engine. Being poor, I did all the servicing, including oil changes. I had heard so much about STP that I decided to add it to the oil. Well the next oil and filter change, I found all my STP in the oil filter cannister. The actual filter material was cotton felt material. The STP would not pass through it and the filter effectively filtered it all out of the oil. Never used STP again.

Paul

I hate to pull answers like this out of my ass, but I'm thinking STP isn't very good. Heavy way oil might be a better choice.

Scott Logan has stated more than once that he uses way oil (Vactra #2, I think) for everything except geared headstocks. And he oughta know.

Scott Logan has stated more than once that he uses way oil (Vactra #2, I think) for everything except geared headstocks. And he oughta know.

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A quick Google tells me I need to try Vactra, it seems ideal for my machines. Thanks! Now, if I could get people to use it on EVERY point....

Vactra has a tackifier to make it stick to ways better than other lubricants. Might keep it stuck to your rollers longer than other oils.

Most of the slant bed CNC lathes I service use #2. I've 'heard' #4 is for vertical apps like VTL's but that might be a wives tale.

Wes