Chain waxing + graphite question

[HarryB]

On 7 Mar 2006 20:40:55 -0800, "41" <[email protected]> wrote:

[snip]
>
>As an aside, carnuba is or at least was also used as a wax on dental
>floss, although paraffin may be used too, perhaps in combination. As
>another aside, MP's example of waxing surfboards interested me and I
>found this:
>
>http://en.wikipedia.org/wiki/Paraffin
>Uses
>
> Candlemaking
> Coatings for waxed paper or cloth.
> Coating for many kinds of hard cheese, like Edam cheese.
> Preparing specimens for histology.
> Solid propellant for hybrid rockets
> Sealing jars, cans, and bottles
> In dermatology, as an emollient (moisturiser)
> Surfing, for grip on surfboards as a component of surfwax.
> [...]
>
Under "General Uses" on the outside of the box of the wax (paraffin) I
use to wax my chains there is listed, among other uses:
"...
3. Lubricate sticking drawers, windows, doors and zipper fasteners.
5. Lubricate snow skis and toboggans.
...."

Harry

 

[41]

41 wrote:
> Peter Cole wrote:
> > 41 wrote:

> > > Yet, paraffin is not dissolved by water and is extremely hydrophobic.
> > > So why do paraffined chains so quickly squeak and rust in the rain?
> > > Think about it.
> >
> > I have. It's much harder to get wax to adhere to a wet metal surface
> > than a dry one, so I assume (speculate) that once water gets into the
> > link and wets the metal it starts eroding the wax film by interfering
> > with the replenishment process.
>
> If this were the case, and the reservoir mechanism is as you describe,
> would not the problem be solved simply by drying the chain, and then
> presto you could use it again without further relubrication?n

And further, if the lubricating paraffin film is actually there, and
since paraffin is so highly hydrophobic, how is water wetting the
surface at all?

 

[41]

HarryB wrote:
> On 7 Mar 2006 20:40:55 -0800, "41" <[email protected]> wrote:
>
> [snip]
> >
> >As an aside, carnuba is or at least was also used as a wax on dental
> >floss, although paraffin may be used too, perhaps in combination. As
> >another aside, MP's example of waxing surfboards interested me and I
> >found this:
> >
> >http://en.wikipedia.org/wiki/Paraffin
> >Uses
> >
> > Candlemaking
> > Coatings for waxed paper or cloth.
> > Coating for many kinds of hard cheese, like Edam cheese.
> > Preparing specimens for histology.
> > Solid propellant for hybrid rockets
> > Sealing jars, cans, and bottles
> > In dermatology, as an emollient (moisturiser)
> > Surfing, for grip on surfboards as a compo nent of surfwax.
> > [...]
> >
> Under "General Uses" on the outside of the box of the wax (paraffin) I
> use to wax my chains there is listed, among other uses:
> "...
> 3. Lubricate sticking drawers, windows, doors and zipper fasteners.
> 5. Lubric ate snow skis and toboggans.

Yes, we used to unstick zippers by rubbing them with a candle. If you
have a loose one around though, you might want to compare the results
with lubricating with grease. Likewise, if you surf, consider what
would happen if you tried greasing your surfboard for grip.

Don't grease the skiis though.

I ask again: why do we not need (and cannot use) skates on waxed
floors, but we do need to use them or something similar on greased
floors and on ice?

 

[Peter Cole]

41 wrote:
> Peter Cole wrote:
>
>>41 wrote:
>
>
>>>Old fashioned paste floor wax, like good automobile wax, relies on
>>>carnuba (carnauba) wax, the hardest and highest melting point natural
>>>wax. It is both chemically and physically very different from paraffin:
>
>
>>I can find no information for the
>>specific formulation of any paste floor w ax. Do you have some, or are
>>you just speculating?
>
>
> I knew in advance that this was the traditional ingredient and the
> reason for that, and googled "carnuba" to find a specific value for the
> hardness- and to also see if it was still commonly used as such.
> Answer: yes, and furthermore it is used for other things far more
> commonly than I would have expected (it used to be expensive). For
> example, it seems we are eating a lot of it.

I have used paste floor wax and carnauba-containing car wax and ski wax,
etc. etc. They are all lubricants because they share the property of
melting at the pressure point and forming a film of high strength
separating the sliding components. This "It's a dessert topping! No,
it's a floor wax!" discussion, while entertaining, is beside the point.

>
>
>>>>Wax sticks well to plastic, and because it's hydrophobic will displace
>>>>the water film between the board and skin.
>
>
>>>Try reigning in the speculation a bit. If what you say were true, then
>>>to dry the soles of my feet, I need only step on a paraffined board. Of
>>>course that does not happen.
>>
>>Of course it does. Try rubbing a wax of your choice under water, it
>>won't be slippery. If the water film remained it would be.
>
>
> Today I wet my thumb, and pressed it against paraffin, either slowly or
> quickly raising the pressure to as high as I could manage. I then
> removed my thumb from the paraffin. In both cases it remained as wet as
> before.

I don't think you're trying hard enough.

> I then tried rubbing that wax both dry, and under water. In both cases
> it was not slippery, and there was not much difference between the two,
> but I would say that the wet wax was slipperier.

As in the case above, you won't get any where near 100% contact between
skin and wax, there will be pockets of water and water in the fingerprints.


>>>>Wax has high film strength, that's what makes it prevent floor scuffs.
>>>
>>>
>>>Carnuba is indeed very strong (strong enough for a bicycle chain? I
>>>doubt it but don't know). However, paraffin is not. Paraffin is also
>>>very brittle.
>
>
> I thought you were referring to hardness, since we were talking about
> the solid state. Film strength usually refers to the liquid state.

Yes, which is where waxes do their lubrication.

>>I'm sure there are many papers describing the use of wax lubricants in
>>industrial applications, here's one I found quickly:
>
>><http://www.hitachi-pm.co.jp/english/seihin/tec-report/2002/pdf/tec2002_e_05.pdf>
>>
>>Sliding Property of F e-Cu-C Sintered Materials under High
>>Contact Stress and at Low Sliding Velocity
>>
>>"If wax is used as lubricant for impregnation instead of oil, the
>>durability of the bearing can be increased, because wax has a stronger
>>film intensity and about
>>2.7 times as large a coefficient of thermal expansion as that of
>>lubricating oil."
>
>
> I give you an "A" for googling but only a "Gentleman's C" for reading.

> The key paragraph is the following:
[snip]
> One reason for the good performance of the wax is
> its high film strength.

This is the only part of relevance to my argument. I was rebutting the
claim that waxes have poor film strength. I'd rather not participate in
broadening the argument.

>>You think waxed floss wouldn't make a difference on dry teeth? I beg to
>>differ. You've obviously not done much hand sewing where bee's wax is
>>used to lubricate the thread. No water there.
>
>
> We are straying very far from bicycle chains (porous reservoir
> bearings, cloth fabric, dental floss). In fact the cloth should have a
> water content similar to the relative humidity of the atmosphere.
> Whatever, obviously paraffin does not make for the highest friction
> pair, I am merely saying it is not slippery (like oil or ice is
> slippery).

It is precisely slippery like ice is slippery, in that under pressure it
melts, forming a strong film that separates sliding parts. Melted wax
does have higher viscosity than water, so the film will have higher
friction than water.


> But this is of no matter: as I said somewhere else, what
> (should be) considered a lubricant depends on the context. Of course if
> you have a very high-friction pair, then putting a medium friction pair
> coating on will help. But the specifics matter: in sewing, the pressure
> between fabric and thread is zilch.

It is certainly not. Do the math if you doubt it.

> In dental floss, you have one
> entry, a few rubs, and one exit, and I don't know that the pressure is
> so high.

Again, do the math.

> In bicycle chains, you have very high pressures and very many
> passes to squeeze any wax, solid or putatively liquid, out from the
> interface, and no mechanism to recirculate it back- unless you want
> porous sintered pins and links. No thanks.

The pin and inner plate shoulder interface bears a load only on a
fraction (less than half) of its surface. The remaining surfaces are
never compressed, so the wax wouldn't be squeezed out. The loaded
surfaces do rotate (unloaded) over the never-loaded surfaces, so it's at
least possible for reservoirs of wax to persist and replenishment to occur.


> As an aside, carnuba is or at least was also used as a wax on dental
> floss, although paraffin may be used too, perhaps in combination. As
> another aside, MP's example of waxing surfboards interested me and I
> found this:
>
> http://en.wikipedia.org/wiki/Paraffin
> Uses
>
> Candlemaking
> Coatings for waxed paper or cloth.
> Coating for many kinds of hard cheese, like Edam cheese.
> Preparing specimens for histology.
> Solid propellant for hybrid rockets
> Sealing jars, cans, and bottles
> In dermatology, as an emollient (moisturiser)
> Surfing, for grip on surfboards as a component of surfwax.
> [...]

I'm not sure what you're trying to show with this list. Wax is not used
as a lubricant on surf boards, but rather as a traction surface.

 

[Peter Cole]

41 wrote:
> Peter Cole wrote:
>
>>41 wrote:
>>
>>>Peter Cole wrote:
>>>
>>>
>>>>41 wrote:
>>>>
>>>>
>>>>>Peter Cole wrote:
>>
>>>>To which paper are you referring? The only reference I can remember is
>>>>to the Spicer paper:
>>>> <http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf>
>>>>which claimed that lubrication had no effect on chain efficiency.
>>>
>>>
>>>That was the claim. However, if you look closely at what they found,
>>>you will see, as I explained in an earlier post, that that is not the
>>>case. They found no difference between an unlubricated chain and a
>>>waxed (i.e., unlubricated) chain, but lubrication (oil) reduced the
>>>energy losses by 17-24% as I stated above.
>>
>>I think you're reaching. To look at the more interesting points (higher
>>loads):
>>
>>At 200W, 60rpm, 52x15, they measured 96.5% for no lube
>>At 175W, 60rpm, 52x15, they measured 97.5% for White Lightning (wax)
>>
>> From the curves, the 175W extrapolated to 200W would be > 98%, so,
>>using your terminology, more than 40% improvement with wax.
>
>
> Thank you for taking the time to do the calculations to prove for me my
> point, which was:
>
> #this reinforces the suspicion that oiling the chain
> #instead of waxing it could reduce energy losses by much more than
> #17-24%, perhaps somewhere towards 40% or more.
>
> Wow- you are making me feel like a prophet.

My point was to address the lubricating qualities of wax. You claimed
the data showed no efficiency improvement of wax relative to bare metal.
I think the data showed otherwise.

 

[Peter Cole]

41 wrote:
> Peter Cole wrote:
>
>>41 wrote:
>
>
>>Since soaking a chain in liquid wax (or the equivalent) deposits a fair
>>amount of wax in the various clearances in the chain, I would assume
>>that normal link articulation would replenish the film just from
>>rotational contact on those reservoirs. Speculation on my part, but I
>>don't know how the proponents of the technique would get the claimed
>>durability otherwise.
>
>
> A good example of replenishment from a reservoir is the porous sintered
> bearing discussed earlier. In that example, the bulk temperature melted
> the wax to a liquid state. I find no comparable mechanism in bicycle
> chains and do not see how wax could be replenished. See also my reply
> to JB which should appear momentarily. I believe the claimed durability
> is simply from the fact that their chains are clean.

This is possible. As far as I know, there are no data for wear rates of
bare chains vs. waxed chains in a clean environment, so we're both
speculating on the relative contribution of metal-to-metal vs.
contaminant abrasion.

Wax is a lubricant in this application, it has the film strength. The
only unknown is whether a replenishment mechanism exists and how
effective (durable) it is.

>>>Yet, paraffin is not dissolved by water and is extremely hydrophobic.
>>>So why do paraffined chains so quickly squeak and rust in the rain?
>>>Think about it.
>>
>>I have. It's much harder to get wax to adhere to a wet metal surface
>>than a dry one, so I assume (speculate) that once water gets into the
>>link and wets the metal it starts eroding the wax film by interfering
>>with the replenishment process.
>
>
> If this were the case, and the reservoir mechanism is as you describe,
> would not the problem be solved simply by drying the chain, and then
> presto you could use it again without further relubrication?n

Perhaps that argument would follow, but perhaps the replenishment
mechanism is from wax particles that get washed away, or perhaps the
water lifts the wax layers in the clearances causing fracture into
particles, which then get washed away, I don't know, and I have no
experience with waxed chains to draw upon.

 

[Peter Cole]

41 wrote:
> Peter Cole wrote:
>
>
>>Although I've never done it, if
>>I had to slide a refrigerator across a floor, I'd expect it to be much
>>easier with that film of paraffin.
>
>
> So would I. The contact area is large and there is only one slide
> anyway. But consider: would it be easier to slide with a film of
> grease? In fact, probably not, because you wouldn't even be able to
> stand up to push or pull on the fridge. Likewise, consider a
> solid-melting lubricant like ice: think of how much easier it would be
> to slide that fridge around- if you had skates to push yourself with.
>
> Why don't you need skates on waxed floors, but you do need something
> comparable on ice or on greased floors?
>

Wax is different than grease in that it exhibits "stiction". It presents
a high friction surface until the pressure melts it, at which point it
shifts to low friction. This phenomenon is obvious in cross country ski
waxes. Ice is similar except that solid ice has much lower friction than
solid wax.

 

[41]

Peter Cole wrote:
> 41 wrote:
> > Peter Cole wrote:

> I have used paste floor wax and carnauba-containing car wax and ski wax,
> etc. etc. They are all lubricants because they share the property of
> melting at the pressure point and forming a film of high strength
> separating the sliding components.

This is the claim, but it is yet to be proved nor a specific (i.e.
bicycle chains, not porous sintered bearings) citation found. In fact,
the only one we have shows that this does NOT occur, waxed chains
showing no lubrication improvement over dry chains. If the situation
were as you say, we would see this improvement. Yes, I know what you
are going to say, see further comments below or in the reply to your
next post on these two items.


> >>>Try reigning in the speculation a bit. If what you say were true, then
> >>>to dry the soles of my feet, I need only step on a paraffined b oard. Of
> >>>course that does not happen.
> >>
> >>Of course it does. Try rubbing a wax of your choice under water, it
> >>won't be slippery. If the water film remained it would be.
> >
> >
> > Today I wet my thumb, and pressed it against paraffin, either slowly or
> > quickly raising the pressure to as high as I could manage. I then
> > removed my thumb from the paraffin. In both cases it remained as wet as
> > before.
>
> I don't think you're trying hard enough.

I think you are trying too hard.

I wish you good luck with your patents on paraffin blotters and the
paraffin drying press.


> > I thought you were referring to hardness, since we were talking about
> > the solid state. Film strength usually refers to the liquid state.
>
> Yes, which is wher e waxes do their lubrication.

This is speculation. They may lubricate by other mechanisms (ski waxes)
and they may not lubricate by this mechanism (surfboards; bicycle
chains?). The specifics matter.


> > I give you an "A" for googling but only a "Gentleman's C" for reading.
>
> > The key paragraph is the follow ing:
> [snip]
> > One reason for the good performance of the wax is
> > its high film strength.
>
> This is the only part of relevance to my argument. I was rebutting the
> claim that waxes have poor film strength. I'd rather not participate in
> broad ening the argument.

You should consider doing that, as the authors were not confident that
film strength was in fact the explanation or even a contributory
explanation. They noted that higher film strength oil was in fact
worse.


> > Whatever, obviously paraffin does not make for the highest fr iction
> > pair, I am merely saying it is not slippery (like oil or ice is
> > slippery).
>
> It is precisely slippery like ice is slippery, in that under pressure it
> melts, forming a strong film that separates sliding parts. Melted wax
> does have h igher viscosity than water, so the film will have higher
> friction than water.

So is it film strength or is it viscosity? And why do we need skates on
ice but not on waxed floors? In some circumstances, like the sintered
bearing, it is clear that it does melt and so lubricates. This is
proved by the fact that when tested in those circumstances, the
friction drops dramatically. Likewise, it is proved that this is NOT
the case in bicycle chains, because this does NOT happen.

>
> > coating on will help. But the specifics matter: in sewing, the pressure
> > between fabric and thread is zilch.
>
> It is certainly not. Do the math if you doubt it.

I was thinking of entering the thread. Yes, when tightening the loop,
it does rise. Do you really think this application is the same as with
a bicycle chain.


> > In dental floss, you have one
> > entry, a few rubs, and one exit, and I don't know that the pressure is
> > so high.
>
> Again, do the math.

What are you talking about. There is no math without instrumenting my
mouth first. Forget it.


> The pin and inner plate shoulder interface bears a load only on a
> fraction (less than half) of its surface. The remaining surfaces are
> never compressed, so the wax wouldn't be squeezed out. The loaded
> surfaces do rotate (unloaded) over the never-loaded surfaces, so it's at
> least possible for reservoirs of wax to persist and replenishment to occur.

That's a better hypothesis, but I'm yet to be convinced that it would
work, for reasons in my reply to JB as well as for the recirculation
mechanism. Without load, how is the wax picked back up. With load, it
is squeezed out. As you can see, it's a ways to go before confirming
that this is actually the way it works. But the final aribiter is that
the measured performance of waxed chains is not improved over dry. See
my next reply to reiterate that they "White Lightninged" the chain in
two different ways, one of which, the one with the improved lubricity,
in fact had a grease residue.


> > As
> > another aside, MP's example of waxing surfboards interested me and I
> > found this:
> >
> > http://en.wikipedia.org/wiki/Paraffin
> > Uses
> >
> > Candlemaking
> > Coatings for waxed paper or cloth.
> > Coating for many kinds of hard cheese, like Edam cheese.
> > Preparing specimens for histology.
> > Solid propellant for hybrid rockets
> > Sealing jars, cans, and bottles
> > In dermatology, as an emollient (moisturiser)
> > Surfing, for grip on surfboards as a component of surfwax.
> > [...]
>
> I'm not sure what you're trying to show with this list. Wax is not used
> as a lubricant on surf boards, but rather as a traction surface.

That is what I am trying to show with this.t

 

[41]

Peter Cole wrote:
> 41 wrote:

> >>>> <http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf>
> >>>>which claimed that lubrication had no effect on chain efficiency.
> >>>
> >>>
> >>>That was the claim. However, if you look closely at what they found,

> My point was to address the lubricating qualities of wax. You claimed
> the data showed no efficiency improvement of wax relative to bare metal.
> I think the data showed otherwise.

Please read again carefully both the relevant sections of the paper,
noting the discrepancies and the curiously missing data points in table
2, and my earlier comments, combined with a bit more explanation below:

#There were several other problems with this study, which I listed in
an
#earlier post. The main one is that they did not validate their
cleaning
#procedure by disassembling the chain and showing that no residual
#grease was left. They themselves seem not to have had confidence in
#their basic procedure, since to obtain what they called a "clean
#chain", they used a much more thorough one: both Castrol Degreaser and

#kerosene in vigorous conditions. To get rid of the factory lube for
the
#basic test, they used only Simple Green [in undescribed conditions].
They had a third cleaning
#procedure, Simple Green and/or Castrol Degreaser, and this accounts
for
#a discrepancy in values I noted earlier:

##There is a discrepancy between table 1 and table 2, where
##for the 52-15 combination @60RPM/100W, White Lightning, we see values

## of 92.3 and 91.1 respectively.
[Note that curiously, the other values are missing from this table.
>From this fact and from the fact that they used a very different and
far more vigorous cleaning procedure to produce the clean chain, I
believe they understood that their primary experimental setup was
contaminated with grease. They even describe the results differently:
for their primary data, the chain was only "cleaned". For the secondary
series, the chain was "thoroughly degreased/cleaned", while for the dry
chain, it was "fully degreased". QED:]

#The lower value of 91.1 is for the more thorough cleaning. This
#difference of 1.2% is significant by their error margins, comes close
#to the 1.7% or so found with oil, and thus proves that their basic
#procedure did not remove the factory lubricant adequately. Their table

#1 for White Lightning is in fact for factory grease plus White
#Lightning.

 

[41]

Peter Cole wrote:
> 41 wrote:
> > Peter Cole wrote:
> >
> >
> >>Although I've never done it, if
> >>I had to slide a refrigerator across a floor, I'd expect it to be much
> >>easier with that film of paraffin.
> >
> >
> > So would I. The contact area is large and there is only one slide
> > anyway. But consider: would it be easier to slide with a film of
> > grease? In fact, probably not, because you wouldn't even be able to
> > stand up to push or pull on the fridge. Likewise, consider a
> > solid-m elting lubricant like ice: think of how much easier it would be
> > to slide that fridge around- if you had skates to push yourself with.
> >
> > Why don't you need skates on waxed floors, but you do need something
> > comparable on ice or on greased flo ors?
> >
>
> Wax is different than grease in that it exhibits "stiction". It presents
> a high friction surface until the pressure melts it, at which point it
> shifts to low friction. This phenomenon is obvious in cross country ski
> waxes.

Are you sure that is the mechanism, is it pressure or is it friction,
or is it the water that is melting. In either case, note that it only
works over a limited range of temperatures, snow sharpnesses, and water
contents. Let's see, in my wax kit I have one generic wax (not
paraffin), two different brand soft waxes, one or two medium hardness
waxes, two or three hard waxes, two or three very hard waxes, one extra
hard wax, one super-hard wax, a ground wax, and then a whole selection
of even more for ice or above zero. When I cork them in, vigorously
rubbing with a cork or the palm of my hand, the friction is very high
and remains so, to the extent that it squeaks. Rubbing with my hand the
temperature can get high (showing poor lubrication), to the point of
hurting. When I melt them in with an iron, so that there really is
liquid layer, the friction is very low. Why do waxed floors squeak when
you walk on them, if the pressure melts them?

 

[[email protected]]

George King writes:

>> # What is or is not a lubricant obviously depends upon context,
>> # meaning the friction pair and the pressure. For example, sand is
>> # not generally considered a lubricant, and I expect you wouldn't
>> # have gone after me if I had said SAND IS NOT A LUBRICANT, but it
>> # will reduce friction if interposed between the adhesive sides of
>> # two pieces of Scotch tape, or for that matter, between a shoe and
>> # a dry sidewalk- or a tire and same. We are talking here about
>> # bicycle chains. Coefficients of friction vary wildly depending
>> # on the precise context

>> Hold it! As I said, this is delving into tribology and from what I
>> read here tribological definitions are missing. The concept of
>> "third body lubricants" includes materials like sand. Although
>> abrasive, such particles work as friction reducers both in the
>> sandy road surface and for instance, in hard disk storage medium in
>> which wear debris reduces friction between transducer sliders and
>> disk.

> In most fields there are lumpers and splitters. The splitters
> sometimes come up with uncomfortably narrow definitions ("glass is
> not a solid because it is not crystalline") while lumpers may come
> up with uncomfortably wide ones ("sand is a lubricant"). Sometimes
> the gap is bridged by judicious use of the prefix "quasi". If I
> empty a bag of ball bearings on the road, have I lubricated it?
> Whether ball bearings or sand, if I want to calculate the friction
> and wear characteristics induced by my act of lubrication, I have
> to consider whether or not the interface between my (third body)
> lubricant and the relevant surfaces is... lubricated. In other
> words, whether or not my lubricant is lubricated! I am not a fan of
> such contortions and would need a compelling reason to accept one.

> My own view is that, in order to avoid idiosyncracies, classes
> should be based on the laws of the system. In other words, systems
> which share the same broad laws should be considered to belong to
> the same broad family. This is the concept of a natural kind. For
> example, the gas laws for gases. Are there broad families of
> tribological equations (laws) satisfied by both third-body
> lubricants, say for example sand, and all other lubricants? If so
> then I would be happier to consider sand as a lubricant, third-body
> or otherwise.

>> You might consider how two solid materials slide on one another.
>> In all cases, one or both materials flow at flash-points if there
>> is no separating lubricant. Asperity contacts cause temperatures
>> many times higher than the apparent bulk temperature and these
>> serve to cause local melting.

> Some amateur remarks:

> I thought that, given the wide variety of calculated asperity
> temperatures, according to the various models and assumptions, and
> given the difficulty of experimentally verifying those temperatures,
> that this mechanism, although proposed some half-century ago, and
> having what could be described as most-favoured theory status, still
> was somewhat unresolved, certainly as a blanket statement for all
> material pairs under all conditions.

http://tinyurl.com/rrlxt (PDF)

> Besides, could not the sliding, although perhaps you would then not
> call it sliding, be accomplished by brittle fracture of asperities
> and accumulation of wax dust. Paraffin is brittle.

"Brittle" in this case is also one of those splitters. Wax smears
when it is rubbed upon and deforms plastically at room temperatures.

> In any case, I wonder about the following. If we are considering
> paraffin-paraffin contact, paraffin is a weak substance. As an
> example, yield pressure appears in the numerator of the expression
> for asperity temperature in Archard's equations, and with hard
> materials having yield pressures in the gigapascals generating
> temperatures in the hundreds of degrees, what is going to happen
> with something as weak as paraffin? On the other hand, if we are
> considering the steel asperities in the chain, then (a) since the
> contact and durations are so local, these must be continual to keep
> the paraffin liquid; (b) would not the temperatures would be high
> enough to locally carbonize the paraffin and locally melt the steel;
> and (c) in any of these circumstances, the paraffin wouldn't be
> lubricating anyway.

> Nevertheless, as I replied to someone else, suppose it really were
> the case that liquid paraffin is being generated and lubricating the
> interface under great pressure. If so, it will be pushed out of the
> interface, and then no longer be subject to the movement and
> friction that melted it. So, it can not replenish the surface
> again. The system is not like a porous sintered bearing that
> someone else had proposed before, which acts as a reservoir for the
> wax, continually replenishing and being replenished. Nor is it like
> friction with ice, where again there is a reservoir to continually
> relubricate the surface. There may be a lot of wax around a waxed
> bicycle chain, but I see no mechanism to allow it to recirculate
> with the contact surface.

In thin films, materials behave differently than in bulk. Displacing
wax from an interface is not done merely by pressing the surfaces
together. Whether wax is liquid in boundary layers or not is
immaterial since boundary layers do not behave as liquids or they
would never remain in such interfaces as lubricants. The definition
of a liquid in this case being that it has no fixed shape or rigidity,
freely agglomerating to its bulk condition after flowing out of such
an interface. Such layers can be removed by energy such as heating or
ultra violet bombardment, and by chemical means. In the case of wax
or oil, water is a sufficient chemical, having a greater affinity for
steel than wax.

Jobst Brandt

 

[Peter Cole]

41 wrote:
> Peter Cole wrote:

>>
>>Wax is different than grease in that it exhibits "stiction". It presents
>>a high friction surface until the pressure melts it, at which point it
>>shifts to low friction. This phenomenon is obvious in cross country ski
>>waxes.
>
>
> Are you sure that is the mechanism, is it pressure or is it friction,
> or is it the water that is melting.

Apologies, to be clear, it's the snow that's melting, not the wax.

 

[Peter Cole]

41 wrote:
> Peter Cole wrote:
>
>>41 wrote:
>>
>>>Peter Cole wrote:
>
>
>>I have used paste floor wax and carnauba-containing car wax and ski wax,
>>etc. etc. They are all lubricants because they share the property of
>>melting at the pressure point and forming a film of high strength
>>separating the sliding components.
>
>
> This is the claim, but it is yet to be proved nor a specific (i.e.
> bicycle chains, not porous sintered bearings) citation found. In fact,
> the only one we have shows that this does NOT occur, waxed chains
> showing no lubrication improvement over dry chains. If the situation
> were as you say, we would see this improvement. Yes, I know what you
> are going to say, see further comments below or in the reply to your
> next post on these two items.

I'm afraid we disagree in our interpretations of the data, to continue
would only be repeating ourselves


>>This is the only part of relevance to my argument. I was rebutting the
>>claim that waxes have poor film strength. I'd rather not participate in
>>broad ening the argument.
>
>
> You should consider doing that, as the authors were not confident that
> film strength was in fact the explanation or even a contributory
> explanation. They noted that higher film strength oil was in fact
> worse.

Once again, I'll stand by my interpretation.

>>It is precisely slippery like ice is slippery, in that under pressure it
>>melts, forming a strong film that separates sliding parts. Melted wax
>>does have h igher viscosity than water, so the film will have higher
>>friction than water.
>
>
> So is it film strength or is it viscosity? And why do we need skates on
> ice but not on waxed floors?

As I said above, solid water is slippery, solid wax is not. With enough
pressure both melt, melted wax is more viscous than melted ice (water).


> In some circumstances, like the sintered
> bearing, it is clear that it does melt and so lubricates. This is
> proved by the fact that when tested in those circumstances, the
> friction drops dramatically.

I don't think the porosity of the bearing surface affects the
lubrication mechanism. It may present a different replenishment
mechanism, but that is unproven.

> Likewise, it is proved that this is NOT
> the case in bicycle chains, because this does NOT happen.

I can't reach that conclusion.

>
>>>coating on will help. But the specifics matter: in sewing, the pressure
>>>between fabric and thread is zilch.
>>
>>It is certainly not. Do the math if you doubt it.
>
>
> I was thinking of entering the thread. Yes, when tightening the loop,
> it does rise. Do you really think this application is the same as with
> a bicycle chain.
>
>
>
>>>In dental floss, you have one
>>>entry, a few rubs, and one exit, and I don't know that the pressure is
>>>so high.
>>
>>Again, do the math.
>
>
> What are you talking about. There is no math without instrumenting my
> mouth first. Forget it.

You can estimate the pressure from the force on the thread/floss
(tension) and the contact area. I'll agree it's not an ironclad argument
since the wax is also coating surface irregularities, so it's a complex
(like most lubrication) scenario. How much wax is melting at the
interface vs. shearing, I don't know. My guess in sewing with waxed
thread is that melting is occurring, but I can't prove it.


>>The pin and inner plate shoulder interface bears a load only on a
>>fraction (less than half) of its surface. The remaining surfaces are
>>never compressed, so the wax wouldn't be squeezed out. The loaded
>>surfaces do rotate (unloaded) over the never-loaded surfaces, so it's at
>>least possible for reservoirs of wax to persist and replenishment to occur.
>
>
> That's a better hypothesis, but I'm yet to be convinced that it would
> work, for reasons in my reply to JB as well as for the recirculation
> mechanism. Without load, how is the wax picked back up. With load, it
> is squeezed out. As you can see, it's a ways to go before confirming
> that this is actually the way it works. But the final aribiter is that
> the measured performance of waxed chains is not improved over dry. See
> my next reply to reiterate that they "White Lightninged" the chain in
> two different ways, one of which, the one with the improved lubricity,
> in fact had a grease residue.

Well it's a hypothesis. What's really needed to settle the matter is the
comparative wear rates of waxed vs. bare chains in a clean environment.
But, if chains wear predominately from contamination, then the claimed
effectiveness of wax must come from its ability to seal the clearances.
My interpretation of the Spicer data showed friction reduction, but then
White Lightning isn't paraffin, either.

>>>As
>>>another aside, MP's example of waxing surfboards interested me and I
>>>found this:
>>>
>>>http://en.wikipedia.org/wiki/Paraffin
>>>Uses
>>> Surfing, for grip on surfboards as a component of surfwax.
>>> [...]
>>
>>I'm not sure what you're trying to show with this list. Wax is not used
>>as a lubricant on surf boards, but rather as a traction surface.
>
>
> That is what I am trying to show with this.t

Solid wax is somewhat sticky to skin, and retains some of that quality
even when wet. In this application the pressure wouldn't be enough to
melt the wax, so there would be no lubrication.

 

[Peter Cole]

41 wrote:
> 41 wrote:
>
>>Peter Cole wrote:
>>
>>>41 wrote:
>
>
>>>>Yet, paraffin is not dissolved by water and is extremely hydrophobic.
>>>>So why do paraffined chains so quickly squeak and rust in the rain?
>>>>Think about it.
>>>
>>>I have. It's much harder to get wax to adhere to a wet metal surface
>>>than a dry one, so I assume (speculate) that once water gets into the
>>>link and wets the metal it starts eroding the wax film by interfering
>>>with the replenishment process.
>>
>>If this were the case, and the reservoir mechanism is as you describe,
>>would not the problem be solved simply by drying the chain, and then
>>presto you could use it again without further relubrication?n
>
>
> And further, if the lubricating paraffin film is actually there, and
> since paraffin is so highly hydrophobic, how is water wetting the
> surface at all?
>

I'm not sure that it is, it may just be washing out wax particles. If it
is, I'd guess that the film isn't complete (has voids), and once the
water wets bare spots, they can't reacquire wax, so the bare spots grow.
It might also be a thermal effect, with water transporting enough heat
from the contact points to inhibit the melting of the wax. There may be
no one on the planet that understands what's going on in these
circumstances, I certainly don't. Wax-water interaction in low speed
high load bearings probably isn't a hotbed of research.

 

[Peter Cole]

Peter Cole wrote:
> 41 wrote:
>
>> Peter Cole wrote:
>
>
>>>
>>> Wax is different than grease in that it exhibits "stiction". It presents
>>> a high friction surface until the pressure melts it, at which point it
>>> shifts to low friction. This phenomenon is obvious in cross country ski
>>> waxes.
>>
>>
>>
>> Are you sure that is the mechanism, is it pressure or is it friction,
>> or is it the water that is melting.
>
>
> Apologies, to be clear, it's the snow that's melting, not the wax.

A further point, ice is rather unique in that melt point goes down with
pressure (in the temp/pressure region of interest). Paraffin doesn't, so
the mechanism of paraffin melting would be from friction, not pressure
related phase change like ice.

 

[41]

Peter Cole wrote:
> 41 wrote:

> > the only one we have shows that this does NOT occur, waxed chains
> > showing no lubrication improvement over dry chains. If the situation
> > were as you say, we would see this improvement. Yes, I know what you
> > are going to say, se e further comments below or in the reply to your
> > next post on these two items.
>
> I'm afraid we disagree in our interpretations of the data, to continue
> would only be repeating ourselves

If you like. But I can't help wondering how you explain to yourself why
these authors neede to use three very different cleaning procedures,
which they respectively described as resulting in a "cleaned" chain, a
"thoroughly degreased/cleaned" chain, and a "fully degreased" chain.
And further, why two of these resulted in significantly different (by
their error margins) efficiency values for the same experimental
conditions. If you'd care to share, you would not be repeating
yourself.á

 

[41]

[email protected] wrote:

> "Brittle" in this case is also one of those splitters. Wax smears
> when it is rubbed upon and deforms plastically at room temperatures.

I agree for e.g. beeswax but for paraffin I believe it would have to be
a warm room. Surely out riding at e.g. 10-15 °C it is a lot more
brittle than plastic.


> In thin films, materials behave differently than in bulk. Displacing
> wax from an interface is not done merely by pressing the surfaces
> together. Whether wax is liquid in boundary layers or not is
> immaterial since boundary layers do not behave as liquids or they
> would never remain in such interfaces as lubricants. The definition
> of a liquid in this case being that it has no fixed shape or rigidity,
> freely agglomerating to its bulk condition after flowing out of such
> an interface. Such layers can be removed by energy such as heating or
> ultra violet bombardment, and by chemical means. In the case of wax
> or oil, water is a sufficient chemical, having a greater affinity for
> steel than wax.

Yes, I should have called to mind frequent comments of yours to the
effect of water having a greater affinity for steel than typical
lubricants. One thing confuses me, more than other parts of this topic:
apart from my own one-shot experience with paraffined chains in days
gone by, my experiences with waxes as a skier, and amateur knowledge,
one of the things that convinced me of the positions I have argued
here, is your own arguments on the subject:

>>Paraffin (canning wax), although clean, works
>> poorly because it is not mobile and cannot replenish the bearing

>> surfaces once it has been displaced. This becomes apparent with
any
>> water that gets on the chain. It immediately squeaks.

#a non liquid lubricant
#cannot re-flow into the contact area once displaced by bearing
load.
#That it is as good as gone is apparent when a more active liquid
such
#as water attaches itself to the polished metal surfaces allowing
the
#last residue of wax to leave. That wax is as good as gone
already.

It does not sound as if you are now quite agreeing with this, or
perhaps it is merely a clarification. Could you clarify a little more?á

 

[[email protected]]

George King writes:

>> "Brittle" in this case is also one of those splitters. Wax smears
>> when it is rubbed upon and deforms plastically at room
>> temperatures.

> I agree for e.g. beeswax but for paraffin I believe it would have to
> be a warm room. Surely out riding at e.g. 10-15 °C it is a lot more
> brittle than plastic.

>> In thin films, materials behave differently than in bulk.
>> Displacing wax from an interface is not done merely by pressing the
>> surfaces together. Whether wax is liquid in boundary layers or not
>> is immaterial since boundary layers do not behave as liquids or
>> they would never remain in such interfaces as lubricants. The
>> definition of a liquid in this case being that it has no fixed
>> shape or rigidity, freely agglomerating to its bulk condition after
>> flowing out of such an interface. Such layers can be removed by
>> energy such as heating or ultra violet bombardment, and by chemical
>> means. In the case of wax or oil, water is a sufficient chemical,
>> having a greater affinity for steel than wax.

> Yes, I should have called to mind frequent comments of yours to the
> effect of water having a greater affinity for steel than typical
> lubricants. One thing confuses me, more than other parts of this
> topic: apart from my own one-shot experience with paraffined chains
> in days gone by, my experiences with waxes as a skier, and amateur
> knowledge, one of the things that convinced me of the positions I
> have argued here, is your own arguments on the subject:

My comment are about the tribology of chain and canning wax, not
whether it is a good method of caring for a chain. I am not in favor
of meticulous chain care and as you may have seen in the FAQ at:

http://www.sheldonbrown.com/brandt/chain-care.html

that IF you must do some of these things to your chain, then there are
a few logical things that occur and I mention those.

>>> Paraffin (canning wax), although clean, works poorly because it is
>>> not mobile and cannot replenish the bearing surfaces once it has
>>> been displaced. This becomes apparent with any water that gets on
>>> the chain. It [the chain] immediately squeaks.

# a non liquid lubricant cannot re-flow into the contact area once
# displaced by bearing load. That it is as good as gone is apparent
# when a more active liquid such as water attaches itself to the
# polished metal surfaces allowing the last residue of wax to leave.
# That wax is as good as gone already.

> It does not sound as if you are now quite agreeing with this, or
> perhaps it is merely a clarification. Could you clarify a little
> more?

I think the two statements above say the same thing in different
words. I see no ambiguity there. Canning wax is not a good chain
lubricant, especially in average dirty road conditions that include
rain.

Jobst Brandt

 

[Patrick Lamb]

On 7 Mar 2006 01:42:33 -0800, "41" <[email protected]> wrote:
>
>Patrick Lamb wrote:
>> On 6 Mar 2006 08:59:38 -0800, "41" <[email protected]> wrote:
>
>> ><www.thefreedictionary.com/thermal+equilibrium>
>> >Noun 1. thermal equilibrium - a state in which all parts of a system
>> >are at the same temperature
>
>OK, so you don't like this source.

No, I don't like the way you're arguing based on a dictionary
definition without understanding the subject. You don't understand
thermodynamics or thermal equilibrium, which leads to your missing the
point w.r.t. dynamic equilibrium. I get the feeling I'm arguing with
a pig, but on the off-chance that you are seriously trying to learn
something, I'll give it one more try.

You mentioned up-thread there was a thermal equilibrium reached at a
given temperature, and (incorrectly) inferred the entire chain was at
this temperature, based on a dictionary definition. You're missing
two things.

First, for the dictionary definition to hold, you can't have a flow of
energy. That means you're no longer driving the chain, so either
friction has dropped to zero (in which case the paraffin does a
marvelous job of lubricating at slightly below body temperature), or
the chain is no longer in motion (and no lubrication is required).

Second, if there is a dynamic equilibrium, the chain is losing as much
heat through radiation, convection, or conduction, as it is gaining in
frictional losses. Those frictional losses are generated at the
junctions between chain parts, and the heat is conducted through the
metal, but for conduction to occur, you have to have a thermal
gradient, which in turn means some parts are hotter than others. The
average temperature of the chain is what's reported (33 C, IIRC).

Pat

Email address works as is.

 

[Patrick Lamb]

On Tue, 07 Mar 2006 06:07:27 -0600, HarryB <[email protected]> wrote:

>On Fri, 03 Mar 2006 17:30:29 -0600, Patrick Lamb
><[email protected]> wrote:
>[snip]
>>I don't think any proponents of waxing the chain on this group have
>>advocated pure paraffin.
>>
>For the record: I use only "highly refined paraffin wax" (description
>printed on outside of box) and am pleased with the results. To date, I
>rode 488 miles on the one bike and 511 miles on the other since I have
>waxed those chains. And I don't plan on waxing tonight.

I stand corrected.

Pat

Email address works as is.