Kuzmin No-waxing thesis

Would it be possible to describe or show a picture of your scraping
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

wrote:
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

wrote in news:1138882148.632720.15070
@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

Hi Nick,
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

Dear Leonid,
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

Leonid,

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

Jay, check out this Science paper:

Science. 2003 Feb 28;299(5611):1377-80.

Yeah, since I'm not at the U of M, all I can get is the abstract. I
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

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.

http://www.ims-plastics.com/main/Show$Id=1168.html

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

Zach, in this note you sounds more of a scientist than Leonid in his
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).