Lubrication Engineering Hack Chat

Rafe Britton will host the Hack Chat on Wednesday, October 19 at noon Pacific.

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You know the old joke: if it moves when it shouldn't, fix it with duct tape, and if it doesn't move but it should, fix it with WD-40. For a lot of us, that's about as far as our expertise on lubricants -- and adhesives -- goes. That's a shame, because with hundreds of years of petrochemical engineering expertise behind us, not to mention millennia more of ad hoc experience with natural substances, just reaching for that trusty blue and yellow can for a spritz is perhaps a wasted opportunity. Sure, it'll work -- maybe -- but is it really the right tool for the job?

Modern lubricants are extremely complex and highly engineered materials, often built atom by atom to perform a specific job under specific, often extremely challenging, conditions. Oils and greases are much more than just the slippery stuff that keeps our mechanical systems running, and while you might not need to know all the details of how they're made to put them to use, a little inside information could go a long way in making sure your mechanism lasts.

We've invited Rafe Britton on the Hack Chat to talk about all aspects of lubrication engineering. With degrees in engineering and physics, Rafe runs Lubrication Expert and the Lubrication Explained channel on YouTube to help his clients figure out what they don't know about lubrication, and how to put that knowledge to use in the real world. Be sure to bring your questions and concerns about lubrication, as well as your lubrication success stories and failures -- especially the failures!

Event Logs

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Hack Chat Transcript, Part 2
Dan Maloney • 10/19/2022 at 21:49 • 0 comments

Rafe12:43 PM
@Andy Pugh I was mainly talking gaseous - there are some air bearings and things like that, but like I said they're very niche.

Sergio Kviato12:44 PM
Please tell about bearings lube

Rafe12:45 PM
Okay, so then most of the solid lubricants act the same. If you look at the molecular structure of graphite, boron trifluoride, molybdenum disulphide, calcite or boron nitride, they all look mostly the same - sheets of atoms with low shear strength.

Thomas Shaddack12:45 PM
Solid lubes are good for vacuum applications. Except graphite.

Andy Pugh12:46 PM
Low shear sheets sounds very use-once?

Thomas Shaddack12:46 PM
Boron trifluoride is a gas...?

Rafe12:46 PM
The choice of which one to use mainly comes down to the operating requirements. You see a lot of Moly used because it has very good oxidation stability - it even gets used in the space industry, where the oxidation stability is very important.

Thomas Shaddack12:47 PM
in space, is it about oxidation stability, or about working even without water molecules like what graphite relies on?

Rafe12:47 PM
@Thomas Shaddack sorry that was a brain fart, I meant boron nitride. Specifically hexagonal boron nitride, because there are a few different isomers that don't have the same lubricating properties.

Thomas Shaddack12:47 PM
yup, the cubic boron nitride is a diamond-class abrasive. (handy for ferrous metals that dissolve diamonds at high temperatures at contact zone.)

Andy Pugh12:48 PM
Why is oxidation stability important in space? Are we talking about the atmospheres in crewed areas?

Rafe12:48 PM
So in space it's a bit weird - in low earth orbit you ironically need really good oxidation stability because there's not much oxygen up there, but the oxygen that is present is in atomic form. So not O2, just random highly reactive oxygen atoms looking for a friend.

Thomas Shaddack12:49 PM
Or about low earth orbits where there are way too many single oxygen atoms, all eager to bond to something? (Yes, space corrosion IS a thing.)

Rafe12:49 PM
Obviously once you get above that, then you're in the clear -the main thing you need to deal with is temperature variation and like @Thomas Shaddack said, the lack of water that would help graphite work.

Rafe12:50 PM
In space applications, that an example where the solid lubricant is actually part of the machine surface - which is the same as moly coated piston rings. Generally it's sputtered onto the surface.

Thomas Shaddack12:51 PM
I saw eg. plastics that are composites with solid lubricant particles embedded in polymer matrix. I also saw eg. electrodeposited nickel codeposited with teflon particles.

Rafe12:51 PM
Moly still gives you that really nice lubricity, but in piston rings it also helped with run in because moly is quite soft. We're starting to move away from moly rings because they're not durable enough for really high combustion pressure and sometimes they flake off, which means bad things for the engine.

Rafe12:52 PM
On the solid lubricants stuff, this video does a better job of visualising it:

Rafe12:53 PM
Also if you're invested in piston rings and liners then I did this interview with a piston ring specialist: he goes into much more detail that I ever could about some of the new spray-bore technologies.

Dan Maloney12:54 PM
So out of curiosity, what's the deal with dielectric grease? What's added to give it electrical properties? Or subtracted, I suppose.

Sergio Kviato12:54 PM
do you have video for bearings lubricant?

Rafe12:54 PM
Great question @Dan Maloney

Rafe12:55 PM
So - dielectrics are an interesting one - there's obviously a lot more interest in the topic now that EVs are starting to become a thing. Getting the dielectric properties right is about balancing the electrical properties of the base oil and additives.

Thomas Shaddack12:55 PM
Could have also answers for improvising high voltage/transformer oil for high voltage hacking.

Rafe12:56 PM
As a general rule - the less polar, the less charge is carried....
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Hack Chat Transcript, Part 1
Dan Maloney • 10/19/2022 at 21:48 • 1 comment

Dan Maloney12:00 PM
Hi folks, let's get started! Welcome to the Hack Chat, I'm Dan, and Dusan and I will be moderating today for Rafe Britton as we talk about lubrication engineering

Thomas Shaddack12:00 PM
Fun thing for solid lubricants. Hexagonal boron nitride vs tungsten disulfide, the latter is much more dense so you get much less volume of the powder at the same gram.

bboyes12:00 PM
My favorite spray can lube for the last couple years is CRC Power Lube

Dan Maloney12:00 PM
Hi @Rafe! Welcome aboard

Rafe12:01 PM
Thanks @Dan Maloney - pleasure to be here everyone

Dan Maloney12:01 PM
Thanks for the early morning sign on, too -- really appreciate it. Can you start us off with a little about yourself?

Ulte joined the room.12:02 PM

Rafe12:03 PM
Sure! My name is Rafe Britton and I'm a lubrication engineer out of Sydney, Australia (hence the early start). I spent 13 years at Mobil where I did one time drilling gas wells in various locations around the world before becoming part of the lubes team. So in the O&G world, I've been as far upstream and downstream as you can get.

Dusan Petrovic12:03 PM
Hi Dan, Rafe, welcome everyone!

Rafe12:03 PM
Spent six years at mobil lubricants as a field engineer assisting industrial customers with technical problems, and now I'm out on my own doing the same thing as an independent consultant.

Rafe12:04 PM
So I now have the fortune of not having to sell any particular product :)

Dan Maloney12:04 PM
Cool, didn't know you were on the exploration and production end of things too!

Rafe12:04 PM
Yeah!

Rafe12:04 PM
I really enjoy lubricants because it's this amazing blend of mechanical engineering, chemistry and physics. Plus it's applicable to anything that moves, so I get to work with alot of different industries.

EcPc12:05 PM
Did some work in clutched AWD systems... Lube was incredibly important.

Rafe12:05 PM
Makes the job really interesting. But anyway, that's my background. My specialty is mostly industrial lubricants, but know enough about engine oils to be dangerous.

EcPc12:06 PM
I believe mobil supplied some sort of tractor hydraulic oil we used in a few systems... had great Mu-V

Andy Pugh12:06 PM
On that subject, what's the "magic" in the "traction fluid" in Rotrex superchargers (and, possibly, also Kopp Variators)?

Rafe12:06 PM
I'm also really keen to help educate people about lubricants and lubrication (which is why I'm here).

Rafe12:06 PM
Great question to start us off about tractor fluids!

Andy Pugh12:07 PM
(I have a Variator and Kopp are insistent that anything but Shell Morlina SL10BL (or something a few letters away from that) will result in instant failure.

Rafe12:07 PM
Ok, so the trick with tractor fluids (from a formulation standpoint) is that a tractor fluid is pretty general purpose. As a rule - it's easy to formulate for a single application, but difficult when it might be used in many different applications. So with a tractor fluid, it often needs to act a little bit like a hydraulic fluid, a little like a gear oil, a little like a bearing oil, a little like a circulating oil.

Sergio Kviato12:07 PM
What the components of Motor Oil. Also what the difference between Gas eng oil and diesel oil?

Rafe12:08 PM
So with tractor fluids, the "magic" is threading the needle between the competing requirements of those different applications.

EcPc12:08 PM
@Rafe Also clutch cooling + friction additives

EcPc12:08 PM
it has to wear a lot of hats

Andy Pugh12:09 PM
I am planning to build a spindle-speeder modelled after the Rotrex, but I was hoping not to have to seal it and/or supply pumped lubricant.

Sergio Kviato12:10 PM
Is there real difference between Oil for motorcycle and car?

Rafe12:10 PM
@EcPc - yes, sorry I forgot to mention that too. It's the same issue we're also having in the industry at the moment with EV fluids. In the interests of efficiency and weight savings, most have gone with a "wet motor" design in which the transmission and electric motor are lubricated...
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