Kuzmin No-waxing thesis

Gene,

See Zach's website article for the new link to the Kuzmin paper.

My reading of the Kuzmin paper is that he is covering a relativley
narrow range of conditions - warm and what may be dirty snow. His
Appendix B identifies 4 cases (conditions) ranging from Case 1 with
Fine Grained snow -2C Air/-4C snow temperatures, two "wet corn" cases
and one "wet fine" condition. The wet condition cases have air temps
of +2C to +5C. Four snow conditions are not a lot for experimental
work. Significantly more cases and tests are needed to establish a
statistical confiedence level of the experimental reliability.

The Kuzmin paper's conclusion is contrary to my observations with
watching ski tourers with "no-wax" skis that are not waxed. Their
unwaxed "no-wax" skis frequently ice which would indicate that some
moisture is being "absorbed" into the surface layer of the p-tex base
allowing for the freezing of snow crystals to the base.

As said, I would be interested in reading the peer reviews of the
Kuzmin paper.

Edgar

wrote:

I read all of Kuzmin's thesis. It did inspire me into further reading
(it had bibliogrpahy) but otherwise it's prety weak "reasearch". His
arguments are mostly pseudoscientific, for example, the argument on
penetration of large molecules of wax versus penetration of small
molecules of water. Many reasons can be found why water does not
penetrate the base (the most trivial one is that the base is
hydriphobic), and, in fact, he does not show what experiments he did to
demonstrate that water does not penetrate the base. I wonder what kind
of "thesis" the writing is. It could possibly qualify as a junior
college research assignment.


I was (as many of you) reading the Kuzmin's thesis. I would like to
share some notes I made for myself:

Page 9: "We have never observed any penetration of water into an unwaxed
ski base. Comment: most of the polymers do absorb water (up to 30 weight
%), but it's true, it absorbs less then 0.01% of its weight. You find
data on that on the internet.
(http://www.dunone.com/dunone2/Products.htm) But, it's not a proof of
absence of pores (hydrophoby, surface tension of water etc.).

Page 14, Table 1: We would like to draw attention to the fact that we
believe that the "Wax absorption" in table 1 is not a true absorption,
but is in fact a film of wax bonded by adhesion to the ski running surface.

Comment: We believe...
Density of wax is ~1g/cm^2 (close to water, I assume because it floats),
2mg on 1cm^2 would be (2/1000 of 1cm) 20µm thick or 2/100mm, that's a
lot. You easily scratch that off with your fingernail.

Page 54: How many pairs of skis, 4 or 6, damned.

Page 55: 3.1 Is obscure to me.

Page 55: more then the half of the tests failed for unmentioned reasons.
I just would like to put a questionmark there. I would hesitate to
publish such selective data. How did the refused glide test data look
like? Or shall he fire his technicien?

Page 55 ff
Test result graphs on paper B: Each case has snow and air temperature
indicated: before, after or average during the tests?

How would a 5km skied pair test next morning (without new preparation,
of course). How would flipping the skis (Not waxed becomes waxed, and
vice versa) look next day.

These things would be a nice double check to exclude the influence of
the glide caracteristics (depending on temperature, softness of the
snow) of the ski. These vary as we know even for skis from one batch.
Look for example at Fig.10 and the reference pairs for case 3 (dotted
lines). It's interesting, isn't it? These reference skis are different
at the same temperature and may react different to rising temperatures.
I guess that the temperature simply rose during the tests and the
indicated temps are averages.


General remarks or suggestions:
I miss something to caracterise the snow. How old, how dirty was it? I
guess from the picture that the test slope was in the woods. Are any
airports or facories close by?

My conclusions:
L.Kuzmin made an interesting work in the right direction. I would
appreciate to save 1-2 h per week skipping waxing. There should be one
solid material gliding at least for transformed and another for fresh
snow. The current situation looks strange to me.

End of my notes.

I of course repeated what many of you have said. I'm wondering what kind
of research ski companies do on base materials. I can't believe they
don't. The current situation might be as it is (spending a lot of time
for waxing) because the glide of pure base materials is already very
good and it takes a lot to improve more and/or the problem gliding on
snows and ices and dirts is really weired.

Gentlemen,
Put on your headlights, it's skiing time and new moon.

Cheers
Holger

Thanks. Warm conditions speak to fluoro and lots of popular waxes, at
least theoretically. I can't emphasize enough that this is a masters
thesis not a public paper, so it wouldn't be peer reviewed unless
submitted to a journal. That didn't stop Kuzmin or someone from
addressing the public through the press, though given the subject it
probably would have leaked sooner or later. Perhaps others will now
replicate it and publish in peer-reviewed journals. I'm not trying to
defend Kuzmin, but point out that if you want to go after him it
should be on the basis of what he claimed, did and concluded. And it
should be taken for the level of research that it is, not what the
press presented it as.

Gene


"Edgar" wrote:

Gene,

See Zach's website article for the new link to the Kuzmin paper.

My reading of the Kuzmin paper is that he is covering a relativley
narrow range of conditions - warm and what may be dirty snow. His
Appendix B identifies 4 cases (conditions) ranging from Case 1 with
Fine Grained snow -2C Air/-4C snow temperatures, two "wet corn" cases
and one "wet fine" condition. The wet condition cases have air temps
of +2C to +5C. Four snow conditions are not a lot for experimental
work. Significantly more cases and tests are needed to establish a
statistical confiedence level of the experimental reliability.

The Kuzmin paper's conclusion is contrary to my observations with
watching ski tourers with "no-wax" skis that are not waxed. Their
unwaxed "no-wax" skis frequently ice which would indicate that some
moisture is being "absorbed" into the surface layer of the p-tex base
allowing for the freezing of snow crystals to the base.

As said, I would be interested in reading the peer reviews of the
Kuzmin paper.

Edgar

Hi Zach,

What about that?
http://www.tagesanzeiger.ch/dyn/lebe...n/585973.html: =ABWenn die
heutigen Skilauffl=E4chen richtig behandelt werden, braucht es kein
Wachs.=BB

And about that: =ABGood morning Mr. Kuzmin,

Regarding "porosity" in UHMWPE skibases:

There are no "pores" in press sintered UHMWPE as some wax manufacturers
tell the people since 40 years.

(I guess the "pore-myth" comes from long ago, when ski had no PE base
and the gliding area consisted of the wood the ski were made of.
Wood is indeed porous in structure, so the wood cells (pores) could be
filled with wax)

Back to UHMWPE: As stated no "pores" are in the material.

The mechanism of waxabsorption in UHMWPE is simple: By bringing the
UHMWPE base material in contact with hot wax ( Paraffin) this "low
molecular PE"
goes into solution in the amorphos regions of the amorphous/crystalline
PE.[as the old chemists said: "similia similibus solvuntur" ].

By cooling down the skibase (on snow) there is a tendency of the wax to
migrate out of the PE matrix as the solubility is a function of
temperature.

I am working in R+D of skibases since 38 years and as stated above,
have never seen a "pore" in UHMWPE, but false theories are
unfortunately longliving!!

Have a nice day

best

Urs Geissb=FChler
Chemical Engineer
Research & Development Manager
IMS Kunststoff AG
R=FCtimoosstrasse 5
CH-3076 Worb
SWITZERLAND
tel: +41(0)31 838 0215
e-mail: http://www.ims-plastics.com=BB

Zach Caldwell wrote:
I hope I didn't make the claim that I was doing anything like "science"
with my little demonstration. I did my experiment to satisfy my own
curiosity on the matter, not to create any indisputable proof. As
Andrey has pointed out - there is huge room for error in my "garage
type" experiment. That's a very apt description of what I did. For
goodness sake, I used electrical tape and printer paper - just what was
lying around. I had to make quite a number of attempts to satisfy
myself that I wasn't simply getting wax leaking around the edges of the
ribbon. I started with just masking tape - and that surely wasn't doing
the job. I ended up with a pretty convoluted layering set-up involving
sandwiching the edges of the ribbon between two sticky surfaces, and
then taping the whole thing down - it reminded me of making roof
flashing. Anyway, it's surely not science, but I'm satisfied for my own
purposes that I saw wax go through the base material.

I realized pretty soon after I started working on skis professionally
that there is a lot of room for applied science in the ski preparation,
but that trying to be truly "scientific" about the development of new
methods, grinds, and treatments is a pandora's box. We don't work in a
controlled environment - there are far too many variables at play. The
best we can do is to work on an empirical model and test variables as
the opportunity arises. In my view Kuzmin's work falls far short of
science for several reasons. It is clear that he has started with
conclusions (which he started to form, by his report, at the 1995 world
championships in Thunder Bay). Then he has selected the variables he
wants to test, ignored the rest, and presented his findings as
indicative of the need for a paradigm shift.

I don't claim to have the ability to explain scientifically the way
that skis work. I do, however, have a pretty large head start on the
scientists out there who approach this work theoretically without any
tactile working knowledge of the materials in use. One micron is what -
a hundredth of a hundreth of a mm? In my experience that's at least an
order of magnitude smaller than the scale that we're actually working
at. The thickness of the ribbon that I tested was 0.02mm as measured on
a digital caliper - suggesting that it was in truth someplace between
0.01 and 0.03mm. I'm sure that, measured on the scale of microns, there
is a great deal of variability in the thickness of the thing. But
experience tells me it doesn't matter too much. If wax is penetrating
one micron it might as well not be penetrating at all. We're not
talking about molecule-size pores in the actual UHMWPE here - we're
talking about sintered structure. Len Johnson has poked a small needle
into one of the 'pores' in a ski base, working under a microscope. I've
measured weight gain in a ski due to what I assume is wax saturation on
the order of 0.7-1.0 grams (using a heatbox). You're not going to get
that out of 1 micron penetration, or a film on the ski base, etc. We
truly needn't get too carried away here.

I've had quite a number of people tell me that I approach the ski prep
business very scientifically. And I've had another handful claim that
I'm totally unscientific and that I should be running computer models,
measuring in microns, etc. I think this is a reflection of a
fundamental misunderstanding of, on the one hand, what science is, and
on the other hand, what ski preparation is.
=20
Zach

Excellent - somebody who knows something. I believe your point is the
same one that I tried to make several posts ago - that we're not
talking about pores in the UHMWPE, we're talking about the amorphous
areas in the sintered PE matrix. From the point of view of a waxer
rather thah a chemist, we're working with ski bases that are capable of
absorbing hot wax - is that correct? Or is it as Kuzmin has stated -
that "no penetration of glide wax into the base is possible. After
scraping and brushing only a very small amount of glide wax cover the
ski running surface as an adhesion film"?

You're link doesn't work for me Urs. But thanks for the clarification.

Zach

Yes, you read Urs correctly Zach. Ski wax penetrates into the base
material.
Kuzmin is wrong.

For other fair readers IMS, where Urs works, makes the most famous
version
of ski bases, named "P-Tex". So if Urs has been there for 38 years he
likely
knows his stuff very well. The IMS website has changed over the past
few years
but has lots of cool information. I'll point people to one of IMS's
current PDF files
on ski bases:
http://files.ims-plastics.com/files/...ning_bases.pdf

This PDF includes tables for the amount of wax absorbsion for different
versions
of P-tex. So this is not hidden information. IMS has been publishing
this info for
years and years.

I wanted to highlight one comment Urs made for skiers in general (I
know Zach
knows this already :-) :
By cooling down the skibase (on snow) there is a tendency of the wax to
migrate out of the PE matrix as the solubility is a function of
temperature.

This is why you really want to brush your ski bases well. So you don't
spent the
first 5km using the snow to brush off this "migrated" wax. Even better,
why you
want to cool your skis down and then do the final brushing.

To make a comment on the Kuzmin paper directly:
I would rate it at most at the level of a senior undergraduate's term
report (aka
an undergraduate thesis). I've actually had e-mail discussions with
several people
about this paper including people at the Mid-Sweden University. The
Swedes
describe the "licentiate" as at half-masters level. The quality (or
lack thereof) of
the paper has people within the university wondering how this got
approved.

Rodney

"Zach Caldwell" wrote in news:1138803936.402894.315360
@o13g2000cwo.googlegroups.com:

I don't claim to have the ability to explain scientifically the way
that skis work. I do, however, have a pretty large head start on the
scientists out there who approach this work theoretically without any
tactile working knowledge of the materials in use. One micron is what -
a hundredth of a hundreth of a mm? In my experience that's at least an
order of magnitude smaller than the scale that we're actually working
at. The thickness of the ribbon that I tested was 0.02mm as measured on
a digital caliper - suggesting that it was in truth someplace between
0.01 and 0.03mm. I'm sure that, measured on the scale of microns, there
is a great deal of variability in the thickness of the thing. But
experience tells me it doesn't matter too much. If wax is penetrating
one micron it might as well not be penetrating at all. We're not
talking about molecule-size pores in the actual UHMWPE here - we're
talking about sintered structure. Len Johnson has poked a small needle
into one of the 'pores' in a ski base, working under a microscope. I've
measured weight gain in a ski due to what I assume is wax saturation on
the order of 0.7-1.0 grams (using a heatbox). You're not going to get
that out of 1 micron penetration, or a film on the ski base, etc. We
truly needn't get too carried away here.

I was looking for a microscope picture I thought I've had seen somewhere
showing a cross section of a saturated ski base. I found something else
instead: http://www.tokous.com/thermo_bag.htm

I can't see correctly what they put on the y-axis. But penetration stops
at about 150µm. I thing we would find this kind of graph elsewhere too.

Does somebody know what and how they actually measured?

Holger

Zach Caldwell kirjoitti:

You're link doesn't work for me Urs. But thanks for the clarification.

If you google for "tagesanzeiger kuzmin" and click on the cached
version of thetopmost hit, you should get the whole nine yards of
German in a flash.

BTW there's no reason for you worry about your futu waxing may well
become obsolete one fine day, but you'll still have your hands full
with finestructuring:-)


Anders

wrote in news:1138835302.596547.186770
@z14g2000cwz.googlegroups.com:

What about that?
http://www.tagesanzeiger.ch/dyn/lebe...n/585973.html: «Wenn die
heutigen Skilaufflächen richtig behandelt werden, braucht es kein
Wachs.»

Hi Urs,

taken from the above link:

"Urs Geissbühler von der Firma IMS-Kunststoff in Worb, dem weltweit
führenden Hersteller von Skibelägen, erklärt dagegen, dass ihn die
Resultate von Kuzmin nicht überraschten: «Er rennt bei mir offene Türen
ein.» Dass man wachse, sei ein Übrigbleibsel aus der Ära der Holzski, so
Geissbühler. «Meiner Meinung nach wirkt Wachs vor allem auf der
psychologischen Ebene.»"

Interesting to hear from somebody how has certainly a lot of experience
in the field. It would be nice to have some data prooving your point of
view. My own skiing tells me the opposite. But I'm aware that my pairs
ski are fare too different to do conclusive testing (not to speak about
lack of time). Many people would be interested to safe time on waxing and
ski instead.

Did your company publish data or tests?

Holger

And about that: «Good morning Mr. Kuzmin,

Regarding "porosity" in UHMWPE skibases:

There are no "pores" in press sintered UHMWPE as some wax manufacturers
tell the people since 40 years.

(I guess the "pore-myth" comes from long ago, when ski had no PE base
and the gliding area consisted of the wood the ski were made of.
Wood is indeed porous in structure, so the wood cells (pores) could be
filled with wax)

Back to UHMWPE: As stated no "pores" are in the material.

The mechanism of waxabsorption in UHMWPE is simple: By bringing the
UHMWPE base material in contact with hot wax ( Paraffin) this "low
molecular PE"
goes into solution in the amorphos regions of the amorphous/crystalline
PE.[as the old chemists said: "similia similibus solvuntur" ].

By cooling down the skibase (on snow) there is a tendency of the wax to
migrate out of the PE matrix as the solubility is a function of
temperature.

I am working in R+D of skibases since 38 years and as stated above,
have never seen a "pore" in UHMWPE, but false theories are
unfortunately longliving!!

Have a nice day

best

Urs Geissbühler
Chemical Engineer
Research & Development Manager
IMS Kunststoff AG
Rütimoosstrasse 5
CH-3076 Worb
SWITZERLAND
tel: +41(0)31 838 0215
e-mail: http://www.ims-plastics.com»

Dear Zach,

Of coarse my work is not perfect, but it possible to find some useable
things even in my Licentiate Thesis. I shall explain my point of view:

1. It is wrong to say "the ski base absorbs wax" or "wax penetrates
into the ski base". We have to talk about solution. No one say "sugar
penetrates into hot tee".
2. Generally we may get some wax into the ski base as a solution.
But then, it is very difficult, almost impossible to get this wax away.
Anyone who have applied some glide wax with intensive color (e.g.
Vauhti Violet) on a transparent base have seen as the base really is
dyed a different color. Once the ski base is colored it cannot be
brushed off or removed with wax remover easily. We have to use steel
scraping to take away the wax together with some ski base. Do we need
any wax permanently in the ski base?
3. For the first we have to answer: why we need glide wax in/into
ski base? Glide wax and ski base (UHMWPE) have a similar hydrophobicity
(http://epubl.luth.se/1402-1757/2006/03/index.html, Paper A, pages
4-5), steel scraped ski base has higher dirt repellence (Paper B) and
ski base has a much higher abrasive resistance (Part I, pages 10-11).
So, why we need any glide waxes?
4. I am not a pure theorist. I have almost 40 years experience in
X-C skiing, as an athlete, as a coach, as a technician. As coach and
technician I did act on 3 Olympics (92, 94, 98), on 4 World
Championships (93, 95, 97, 99) and on many WC stages. I had been
employed on the Ski-go wax factory 1992-94. I did race on dry steel
scraped skis many times by my self and I did successfully prepared skis
by this method for other skiers (but they did not know about that).
5. What we see on the pictures on
http://www.engineeredtuning.net/Basematerialdemo.htm is not a scraping,
it is a chipping. It is not possible to get a good glide by this
treatment. Your treatment (chipping) is not able to make optimal
patterns on the ski base, see Paper A, page 4, Table 1.
6. Quite remarkable, Paper A did not get any attention from X-C
society. All attention is focused on Part I and on Paper B.
Nevertheless, it is results from Paper A comes into collision with a
very old assumption - contact angle on PE ski running surface treated
with a conventional glide wax is about 80-90=B0 (Part I, page 23). This
assumption is a major argument why we have to wax our skis with HF
waxes.

With best regards,
Leonid Kuzmin

Zach Caldwell wrote:
Excellent - somebody who knows something. I believe your point is the
same one that I tried to make several posts ago - that we're not
talking about pores in the UHMWPE, we're talking about the amorphous
areas in the sintered PE matrix. From the point of view of a waxer
rather thah a chemist, we're working with ski bases that are capable of
absorbing hot wax - is that correct? Or is it as Kuzmin has stated -
that "no penetration of glide wax into the base is possible. After
scraping and brushing only a very small amount of glide wax cover the
ski running surface as an adhesion film"?

You're link doesn't work for me Urs. But thanks for the clarification.
=20
Zach