Kuzmin No-waxing thesis
Edgar
scraping being better than waxing. The paper's abstract says that
stonegriding and waxing are not as good as an alternative treatment.
Kuzmin theorizes that steel scraping is better than waxing because it
picks up less dirt.
Zach's website has an interesting experiment and commentary cahllenging
the Kuzmin thesis.
http://www.engineeredtuning.net/Basematerialdemo.htm
Peer review reports should be interesting.
Edgar
revy...@yahoo.com
(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.
revy...@yahoo.com
conclusive, either. E.g., I was not convinced the wax did not leak
around the seal that he made around the ribbon. Also, it's not clear
how thick the ribbons were, and how consistent the thickness of the
ribbons is.
I think the right question to ask is not if the wax penertrates or not
(an all-or-nothing kind of question), but how deep the wax penetrates.
A garage type experiment may not address this. Say, the penetration is
1 micron. Then, one will need 0.5 micron thick ribbons to detect
penetration by Zach's method. I am not mentionning that roughness of
the surface of the ski is probably on the order of 100 microns which
makes this all even more complicated.
One could dissolve a fluorescent dye in wax, wax the skis, then make a
slice of the ski and see the gradient of the fluorescence. But this is
not a garage type experiment.
Zach Caldwell
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.
Zach
cpella
You should ask the ski manufacturers if they can send you some
longitudinal slices of base material of different depths of say .1 mm
increments ( would have to be a pretty good bandsaw :-) ). Then you
could repeat your "garage" experiment to see how far the wax actually
can penetrate. I think if you got up to 1 mm you can safely rebuke his
thesis.
And if Kuzmin's theory is based on flimsy premises, I also wonder how
bad or anachronistic his ski testing methodology is?
What is the current state of the art for testing glide at the WC level?
Chris
Zach Caldwell
non-scientific (!) I can "feel" how deep the wax goes when I'm metal
scraping good base material. I'd say we're talking about several
hundredths of a mm - probably not even 0.1mm.
In fact, I believe that Toko (and probably other wax companies) have
done actual scientific tests to determine how deeply wax saturates the
base. I'm sure Ian Harvey would be happy to comment. Or you could try
looking up the Toko Tech Manual which is actually a fairly useful
document. Plenty of propaganda, but also plenty of good information.
There is no state of the art of glide testing on the world cup. Speed
traps are used, but everybody recognizes their limitations. The major
issue with glide testing on the world cup is that there is very little
opportunity for controlled bench-mark testing because most of the
process is geared toward race skis. It's a question to coordinating the
confluence of lots of different variable, the most important in most
cases being ski selection. The skis really have to be skied for feel.
Anyway, Kuzmin has used accepted ski testing methodology. No problems
there. But by the same token his data is pretty thin, and most people
with experience running speed traps would want to see much more.
Z
NordicSkiRacer
read it). But no one has addressed the most important question to a
racer: Is a structured and waxed ski faster than a steel-scraped and
unwaxed ski? And does the difference in "fastness" change over the
course of a race?
Rather than figure out if a ski holds wax, perhaps the test should be
to compare sets of skis just after they are waxed/not waxed and after
they have been skied in. For example,
1. Multiple glide tests (the before test) of structured/waxed skis and
scraped/unwaxed skis are performed, with an average & standard
deviation taken.
2.Both sets of skis are skied on.
3. Periodically - every 5km? - the skis are glide tested.
The results would show which set of skis was faster or slower at the
start (when most racers test glide) AND which skis got faster or slower
relative to the other set over time.
Simple test - although there are lots of variables that would be
difficult to control. Do enough tests, and patterns begin to appear...
Mike
Zach Caldwell
simple test. But you need data. So far the information I have is
anecdotal - not enough hard numbers involved. However, the metal
scraped skis have been very, very far from competitive. When/if I come
up with anything I can call "data" I'll share it, for sure.
However, anybody in their right mind would be crazy not to question my
findings. Talk about a conflict of interests! Having tested hand
structures based on metal scraping as part of my regular testing over
the past four or five years I'll say up front that I'm extremely
skeptical. When I bought a stonegrinder I had already had plenty of
experience working with hand stuctures, and I didn't spend all that
money because I thought that grinding MIGHT be faster.
I would suggest that anybody who feels that Kuzmin's work is convincing
should run their own tests. Competition testing is always the best way
to get good information in any case. It can be hard to determine what's
"significant" in benchmark testing. Less hard at the mid-point of a
marathon. I'm really looking forward to hearing the Birkie stories from
the people that do the metal-scrape/no-wax treatment. Naw THAT will be
some data!
Zach
Gene Goldenfeld
licentiate dissertation is typically a third year graduate paper, the
equivalent of a masters thesis in the U.S. It's rare that the quality
of research at this level can make it past an "Interesting," and then a
specialty library shelf. My experience was that these are more useful
for their bibliographies than their substance.
It's normal to start with a hypothesis, which is anywhere from a hunch
to a conclusion, to be tested (in this case, it's the null hypothesis
that's at issue). Fishing expeditions (data mining) without hypotheses
are not research, tho many economist's models are built that way. The
key is whether the methodology and variables chosen allow for results
to come out either way, or are highly stacked toward the a favored
conclusion. I have to take a pass here.
I do think it's essential to distinguish between two kinds of tests and
claims. The first, and most important, was a skiing test: Does adding
glide wax to skis vs. some nude condition make a difference in the
field? I understand Kuzmin reported a variety of results. The second
are any tests or explanations for the causes of those results. In
speaking to Kuzmin's claims, I think many comments are tending to
overlook the first and jump to the second, i.e., "It can't be true
because it doesn't make any sense according to existing theory or my
lab experiments..."
Gene
Bjorn A. Payne Diaz
You might consider comparing freshly ground skis with and without wax.
That would be limiting the variables to adding wax, and the change in
base structure that occurs because of scraping and brushing. You could
scrape and brush the unwaxed ski, but you have to make sure to have a
new brush and clean the scraper so you don't introduce wax.
Another test (hate to keep adding work) would be to test steel scraped
skis with and without wax. (Same reasoning as above.) It sounds like
you're testing steel scraped without wax vs. ground with wax. I think
the other tests would fill in the "holes" (not a scintering pun) of
it's really the wax making the difference or the ski base structure.
I started reading the thesis and it already seems like an editorial
rather than a scientific paper. I think the wax companies are probably
correct with ideas like wax penetration and that waxing a ski prevents
abrasion, but probably don't really know why. I don't think there's any
reason to worry about "oxidation" of a ski base, but I'll read further
and comment later.
Jay
Edgar
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
Holger Neupert
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) 20痠 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
Gene Goldenfeld
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
leon...@msn.com
What about that?
http://www.tagesanzeiger.ch/dyn/leben/wissen/585973.html: «Wenn die
heutigen Skilaufflächen richtig behandelt werden, braucht es kein
Wachs.»
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: urs.geis...@ims-plastics.com http://www.ims-plastics.com»
Zach Caldwell
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
rod...@skiwax.ca
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/Extruded_and_press-sintered_running_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
Anders
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 future: waxing may well
become obsolete one fine day, but you'll still have your hands full
with finestructuring:-)
Anders
Holger Neupert
@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.
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 150痠. I thing we would find this kind of graph elsewhere too.
Does somebody know what and how they actually measured?
Holger
Helgor Teupern
leon...@msn.com wrote in news:1138835302.596547.186770
@z14g2000cwz.googlegroups.com:
> What about that?
> http://www.tagesanzeiger.ch/dyn/leben/wissen/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
leon...@msn.com
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° (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
NickBrown
process? Having spent a certain amount of time metal scraping, having
learned much from zach, I would be interetested in knowing what
'scraping' means to you. 'Scraping is maybe not the best word, be
'peeling' is perhaps better for what zach is doing, although 'base
peeling' in this country already is associated with another process
(base shaving?). Symantics may be cluttering things a bit, but I am
very glad to hear that the scraping in your process is different from
what Zach uses.
The strands that come off in zach's method are of high integrity and
can be the full with of the ski (to the center groove) and nearly the
full length of the ski. There is virtually no macro-texture remaining.
I tried to photograph some very clean scraping, but havn't had so much
success yet. Suffice to say, that it looks very much like a glass
surface when zach is finished. To me this is a true basemark.
"chipping" to me implys a rough, irrecular and abrupt removal - like a
dull scraper on CH4 - the process used by zach is much more like using
a cheese slicer perhaps.
A 'rougher' scraping job does leave a texture which is in many ways
functionally equivalent (but very differnet) from a stonegrind pattern
in terms of generating turbulance. Some stonegrind patterns can be made
fine enough and clean enough to resemble a scraped ski base.
Could you supply pictures of your scraper, scraped ski base vs ski base
or describe the process?
Also, have you measured the heat generated while scraping? I know that
a dull scraper generates significant heat --- but that is in the area
of Zachs expertise.
I do seem to remember hearing stories from thunder bay of trying to
remove all wax and structure from the skis - but I haven't heard of
similar conditions in the years since.
-Nick
Holger Neupert
@g49g2000cwa.googlegroups.com:
> 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° (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
>
Of course we care mainly about paper B and glide on real snow. Interesting
to read, though.
The idea of gliding on unwaxed surfaces is tempting. Your data presented in
paper B is a little thin to proof it, I think.
Cheers
Holger
leon...@msn.com
It is not so easy to describe in writing (especially with my English)
how I scrape the base, much easier to show. But I can not present any
movies or pictures on this forum.
Removed material in my case does not look as a chipping (cutting
waste), it looks as a sawdust or as a fleece.
I have to remain, that steel scraping of ski base was a commonly
accepted and commonly used from end of 1970s until beginning 1990s.
Leonid
Zach Caldwell
Thanks for taking the time to address some of the criticism that has
been levelled against your work. I'm sure it has been difficult to see
your paper come in for so much criticism by people who have not done
the research and who don't have the many years of experience that you
have.
Adressing your last point - you should rest assured that your Paper A
has, received significant attention, at least from me. As I have
mentioned in many places, the research is very interesting, and should
be taken seriously. I am not a scientist, and I don't measure contact
angles, etc. However, I have been interested in surface roughness and
have been working on a method to apply a controlled microstructure to a
ski base for some time. I think you have identified a very important
point.
However, I think that you have very effectively shot yourself in the
foot with a poorly considered presentation. You have boldly challenged
the "mantras" of established practice, but you have challenged them
with information that is at times false - or at least misleading. I
have made no attempt to discredit your research. However, your
step-by-step assertion that a ski base cannot absorb ski wax because it
doesn't absorb water is flawed and foolish, and runs counter to basic
observations. You yourself have just noted that wax can stain a base,
and that wax can be absorbed "as a solution". Perhaps this is different
enough from "penetration" to warrant some caution in the use of
terminology. But your insistence that ski wax only forms an adhesion
film on the surface of the base does not do much for your credibility.
You might have done better by starting with the question of whether we
need any wax in the ski base, rather than pointing out the stupidity of
the conventional wisdom. Your approach has simply ensured that you make
a lot of people angry.
I think you have made other assumptions that have led you to make
inappropriate and inaccurate generalizations. For instance, your
initial decision to focus only on lubrication and surface
contamination, leaving aside solid deformation, ploughing and capillary
attraction is probably intelligent from the perspective of experimental
design, but it does not strengthen your case when you make broad
generalizations based on your research. For instance, you have stated
that the results of Paper A and your pattern analysis (based only on
concerns identified in your examination of lubrication and surface
contamination) demonstrate the need to find a process other than
stonegrinding for preparing bases. Having just ignored the factors of
solid deformation, ploughing and capillary attraction, not to mention
the role of what I will call macrostructure - or the grind pattern on
the ski - you have claimed that stonegrinding is not the best way to
treat the ski base. Once again, a foolish choice - you've now alienated
not only the waxers, but the stonegrinders - and all based on a very
incomplete analysis (by your own admission) of the factors governing
ski speed.
I can continue to give examples of where you have made misleading
assumptions and stupid generalizations, but to use your words :"this is
sufficient to understand how hard it is to find any grain of
rationality this matter".
Regarding your point #5 - it has been clear to me that your metal
scraping process cannot be the same as mine. I'm not quite sure how you
arrive at the term "chipping" for what I do. Perhaps in Russian and
Swedish "chipping" means something other than what I understand it to
mean. I normally use a steel cabinet scraper that I sharpen with a
burnisher, but I have also used an HSS metal scraped similar to the one
you have shown (with a 90degree rather than an 80 degree edge). I
believe I have seen the result of the process you use - my observation
is that the base material is lifted from the base, and then much of it
is rolled back onto the base under considerable heat and pressure. The
result is a sort of "frosted" appearance. Under magnification the
sintered structure of the base material is no longer apparent and a
highly roughened surface is the result. If you try to wax this surface
it is true that little or no wax will penetrate. It is also true that
this surface stays relatively fast in wet snow, and I have used it in
races. I have also tried to use this preparation in colder conditions
with dry snow and I have had no success. I will readily admit that I
have, each time, waxed the ski after sealing the base with a metal
scraper. This has most likely made it somewhat faster to start with,
and then made it slower. But I think in many cases the wax has been
stripped of the surface almost immediately. I have also not tested this
preparation sinse I started stonegrinding skis, although I have worked
on ways to seal the base AFTER grinding. Your research has prompted me
to test these sealed bases again.
Incidentally, my "chipping" process, which might better be called
"peeling" as Nick Brown has pointed out, can be quite fast in dryer
snow when additional hand structure is added, and it is waxed
(horrors!). I don't know whether you have tested this process, but if
you consider the current term to describe it to be "chipping" I am
guessing that you might not have a good understanding of the process.
Well, that is probably enough for today. I think you have done some
interesting research Leonid, but I think that you have presented it in
a poor light and that you have probably made life very difficult for
yourself. It is always hard to challenge existing paradigms. If it is
your aim to make skis faster and to convince people to use your process
then you should set about making fast skis. The market will always
gravitate toward successful treatments (a distinctly capitalist
notion). If your conclusions are correct you could probably do very
well selling a special "kuzmin" metal scraper! If, on the other hand,
you aim is to insult the intelligence of a great many people and ensure
that you get very little respect and no thanks from the collective ski
racing community, then you have set about it in just the right way.
Especially with the many press-releases coming out as much as a year in
advance of your paper.
Best wishes,
Zach Caldwell
Bjorn A. Payne Diaz
Can you describe the proposal by Wenzel on surface roughness. My
thought would be that the contact angle is larger when the H-bonds are
more ordered (stronger overall bonding). So if you add a solute to the
water droplet, the contact angle is reduced. If the surface is more
hydrophobic and doesn't bond well with water, the contact angle is
increased.
So if the surface is rough, you have hindered perfect water order, and
I'd expect the contact angle to be reduced, just as you measure. You
state:
cos theta w = r (cos theta y) where r is the roughness factor.
and then state roughness makes the hydrophobic surface more
hydrophobic. (It seems opposite to me.) Can I assume the cos theta y
(Young's) is the measured contact angle?
Jay Wenner
revy...@yahoo.com
Science. 2003 Feb 28;299(5611):1377-80.
Bjorn A. Payne Diaz
feel a little odd commenting on the paper without studying it closely
but:
-CH8 on a scraped ski has a lower contact angle than the bare ski. This
suggests CH8 is less hydrophobic than the petex. Nothing earth
shattering there.
-CH8 on a ground ski has a higher contact angle than the bare ski, but
a lower contact angle than CH8 on the scraped ski. This suggests that
the wax reduces the roughness of the ski and this reduction in
roughness has a greater effect than (the reduction) in hydrophobicity.
Even though it reduces the roughness, it doesn't reduce it to the point
of a scraped ski. This seems to be the opposite conclusion of Loenid.
-Different bare grinds have different contact angles. This suggests the
grinds have different roughness. So, more rough, lower contact angle.
(Again, opposite of Loenid if I interpret this correctly.)
The discussion section is pretty brief and doesn't discuss these
points.
I'd go look up the 1936 Wenzel reference, but geeze, I'd actually have
to drive to the U and do some work.
Jay Wenner
Janne G
NordicSkiRacer
leon...@msn.com wrote:
> ...But I can not present any movies or pictures on this forum...
> Leonid
Hi Leonid,
If you have any movies or pictures, I can publish them for you on
http://NordicSkiRacer.com to aid in the discussion.
Mike
revy...@yahoo.com
thesis. You spelled out my thoghts exactly. To a scientist, Leonid's
thesis just can not qualify as a scientific research. You experiment on
wax absoprtion is more scientific than Leonid's writings. (Not that I
am trying to talk you into selling me another pair of great skis at a
discount).
NordicSkiRacer
have reduced the size so it doesn't take up so much bandwidth - it's
now about 1.7MBs. You may download it at
http://www.nordicskiracer.com/Equipment/waxing/kuzminsteelscraping.wmv
Mike
Gene Goldenfeld
http://www.skinnyski.com/gear/display.asp?Id=4430. An interesting
point: he waxed Kuzmin's wife's skis for the Birkie a few years back
and says it took 3 days to undo the damage Kuzin had caused.
Gene
"Edgar" <ej...@juno.com> wrote:
> Zach may be too busy to post his response to the Kuzmin paper on steel
> scraping being better than waxing. The paper's abstract says that
> stonegriding and waxing are not as good as an alternative treatment.
> Kuzmin theorizes that steel scraping is better than waxing because it
> picks up less dirt.
>
> Zach's website has an interesting experiment and commentary
> cahllenging the Kuzmin thesis.
> http://www.engineeredtuning.net/Basematerialdemo.htm
>
> Peer review reports should be interesting.
>
> Edgar
>
rod...@skiwax.ca
It always takes a lot longer to write than for someone to read.
I just wanted to add a comment about the Red Creek steel roto
brush. As Ian highlights Kuzmin used it after waxing and Ian
takes him to task on this. My comment is that Red Creek has
been very specific about when a steel roto brush should be used.
It has never been suggested that a steel roto brush be used after
waxing with warm waxes. Which makes it all the more questionable
why Kuzmin did this.
Rodney