Sintered vs Extruded Ski Base

[Stephen]

Thought I would start a new Subject, based on some comments in another thread.

I wonder about the qaulity of the base on the WL Asnes models...
Anyone know if they are sintered or are they extruded?
What is the wax-retention like on the WL version?

The Enlgish Asnes site has the Nansen BC description posted to the Nansen WL base descriptor-

From the Norwegian site- "ekstrudert"= extruded.

What is the wax-retention like on the Nansen WL- especially on refrozen, abrasive snow and ice?

I have wondered about the sintered / extruded thing myself.
For example, I “think” the base on my Voile Objective BC are extruded.
They sure don’t hold wax well, no matter how well I prep them.
I’m wondering if some skis are made with a combination of the materials: sintered for the glide surfaces and extruded for the traction surface?
It seems like the extruded material is shinier than the sintered.
I’ll look later and compare the bases on my Wax and WL Ingstads to see what I can see.

Maybe others have more knowledge of these things?

[Montana St Alum]

My understanding is that extruded bases are made by melting polyethylene pellets together and sintered by crushing them. It seems as though having a combination would be creating an inferior base at a higher cost (compared to the more expensive sintered bases), so I doubt those are available.
I think that, because they're melted down, extruded bases don't have "pores" that can hold wax, whereas sintered bases do.
Are "fish scale" skis generally extruded? It seems that would be a better design in some ways, since wax retention isn't as much of an issue and extruded are generally easier to patch, I think.

[lilcliffy]

I’m wondering if some skis are made with a combination of the materials: sintered for the glide surfaces and extruded for the traction surface?

Fischer's Offtrack-Crown insert is extruded- the shovel and tail are sintered. Stroke of genius.

A quick Google Search didn't give me a good article on skis- but here is a very good article- focused on snowboards:
https://snowboardingprofiles.com/extrud ... st-for-you

The reason I asked about the Nansen WL specifically is that I am considering using the Nansen WL as both a waxless hilly touring ski for my extended spring skiing (with extremely-wide temperature ranges and lots of abrasive refrozen snow), as well as grip-waxing it in the heart of my winter. As extruded bases do not retain wax as effectively as sintered bases- I am wondering about the pros and cons of this...On the one hand- having longer wax retention is desired- but on the other hand, a stripped extruded base glides better than a stripped sintered base...

I am starting to think that the extruded WL Nansen is the version I would want...
And- also- this would equally apply to my intended use of a ski like the Sverdrup-
I think that I would prefer the WL version of the Sverdrup over the waxable...

[Stephen]

Thread drift already, but…
I have been thinking I would like a T78 for variable temps and spring snow (XCd).
Then I came into a shorter pair of Ingstad WL (which I have not had a chance to ski yet), so will see if that fills the gap.
I got to try a shorter (than my recommended) length T78 for a few minutes and thought they seemed fine.

As for the original subject, I’m somewhat familiar with the differences in materials, and waxing characteristics.
@lilcliffy’s comment on the mix of materials on the Fisher is interesting.
On the Objectives BC, it’s not really an XC ski (desire for glide), so the cost and complexity of mixed materials would not make much sense, from a marketing perspective, even though it might be desirable from a user perspective.
Although, the non-BC version of the Objective does have a sintered base, so it would be nice if Voile (and Åsnes) matched Fisher’s practice of constructing their BC skis with sintered glide surfaces.
Åsnes says this:
“Sinter sole
If you disregard the waxless skis, we manufacture all of our skis with a waxable sintered sole of higher quality than often found in BC and alpine touring skis.”

I wonder if there is some limitation in terms of putting a fish scale pattern on sintered bases?

[Woodserson]

I have a Kneissel 59 (It's like the Fischer Country BC) that's extruded base, the entire base. Hard plastic, does not hold wax well. Or at all. It's terrible.

I have many Fischer products with the superlatively good Offtrack Crown. The scale portion is the extruded hard shiny plastic like the Kneissel ski, and inserted separately into the base with sintered glide portions fore and aft. Sometimes I wax portions of the extruded scale section, it usually doesn't last too long.

I have two Objectives, a WAX and a BC (nonwax). On the BC there is not split between scales and base, like the KOM, it is all one piece. However, the glide-portion of the base of the BC and the base of WAX are indistinguishable by touch or eye to each other. I, unlike Stephen (for whatever reason), do not have any problems with glide wax longevity on my Objective BC's (or KOM's).

I wonder if by "extruded" they mean they stamp the scale pattern into the base and don't pattern it, so it looks hard and shiny. I could be wrong, but I have never really looked at my Objective BC's, KOM's, or Nansen WL's and been like, "yup that glide portion looks like those Kneissel's or the Offtrack Crown." Never. It totally looks and feels like a sintered base.

I don't know though. Just speculation.

[Montana St Alum]

[/quote]
Fischer's Offtrack-Crown insert is extruded- the shovel and tail are sintered. Stroke of genius.
[/quote]

Technology is great!

[Shenanagains]

Not a lot to add here except that Voile waxless models have had sintered glide zones in the past, and an obvious seam between the glide and patterned sections of their bases.

Did that change at some point?

[Stephen]

@Shenanagains made me look…
I am feeling quite unobservant!
There IS a visible seam at the beginning and the end of the fish scale pattern on the Objective BC, I had just not noticed it before.
@Woodserson might want to double check his — I would bet his are the same as mine (three seperate pieces of plastic on the base.
This still leaves the question as to whether or not the Objective BC has a sintered base.
On the Voile website, it clearly says that the non-BC Objective has a sintered base.
Whereas, the construction specs for the BC version make no mention of sintered bases.
Since that is a valuable feature, I would be surprised if the just forgot to call that out.
That’s worth a call to Voile by me on Monday to find out.

As for the difference in our experience of wax longevity on the Objective BC, maybe the difference is subjective.
Maybe as long as it lasts seems “normal” to @Woodserson.
I have the sense it’s gone faster than I would expect, but maybe my expectations are not realistic.
I’m using Swix Universal Glide Wax. Maybe he’s using something better?

As a side note, I also glide wax the fish scales and don’t think I have noticed a discernible loss of traction, and hope that I get more glide, but have my doubts about that.

I think its definitive that the Asnes WL skis do not have sintered bases, since they implicitly say so on their website.
https://www.en.asnes.com/the-inside-of-our-skis/
“Sinter sole
If you disregard the waxless skis, we manufacture all of our skis with a waxable sintered sole of higher quality than often found in BC and alpine touring skis. This gives good wax absorption, better waxing properties, good gliding, and a long-lasting sole. All of our skis come with soles and grinding specifically chosen to function optimally in Nordic and polar conditions.”

[Woodserson]

@Shenanagains made me look…
I am feeling quite unobservant!
There IS a visible seam at the beginning and the end of the fish scale pattern on the Objective BC, I had just not noticed it before.
@Woodserson might want to double check his — I would bet his are the same as mine (three seperate pieces of plastic on the base.
This still leaves the question as to whether or not the Objective BC has a sintered base.
On the Voile website, it clearly says that the non-BC Objective has a sintered base.
Whereas, the construction specs for the BC version make no mention of sintered bases.
Since that is a valuable feature, I would be surprised if the just forgot to call that out.
That’s worth a call to Voile by me on Monday to find out.

As for the difference in our experience of wax longevity on the Objective BC, maybe the difference is subjective.
Maybe as long as it lasts seems “normal” to @Woodserson.
I have the sense it’s gone faster than I would expect, but maybe my expectations are not realistic.
I’m using Swix Universal Glide Wax. Maybe he’s using something better?

As a side note, I also glide wax the fish scales and don’t think I have noticed a discernible loss of traction, and hope that I get more glide, but have my doubts about that.

I think its definitive that the Asnes WL skis do not have sintered bases, since they implicitly say so on their website.
https://www.en.asnes.com/the-inside-of-our-skis/
“Sinter sole
If you disregard the waxless skis, we manufacture all of our skis with a waxable sintered sole of higher quality than often found in BC and alpine touring skis. This gives good wax absorption, better waxing properties, good gliding, and a long-lasting sole. All of our skis come with soles and grinding specifically chosen to function optimally in Nordic and polar conditions.”

Good catch Shenanagains! Yes there is a seam on my Objective BC's.

As for Asnes, who knows what they are talking about. The translation/info on that site leaves a bit to be desired. I also have two MT51's here... my WAX and Cannatonic's WL's (which are totally terrible). The bases look and feel exactly the same to each other.

The difference between my Objectives, Nansens, and MT51's are so indistinguishable to me, I am going to speculate that extruded bases made today are probably better than extruded bases made in the past (such as my Kneissl skis for instace) and so I'm not going to even worry about it. It's a performance function I don't even think I can quantify.

Wax wise, I'm just hot waxing TOKO glide blue/red/yellow depending on temp. Nothing fancy. I rarely scrape unless it's blue. Either way, both skis seemed to wear wax as the other.

[fgd135]

Sintered bases are made from ptex/poly pellets crunched under tremendous pressure, creating the pores that help anchor wax on bases, are harder than extruded plastic bases, and have superior glide characteristics. Bases are machine-skived from the material, and waxless patterns have to be cut or machined, in general, but the material and process is expensive compared to extruded plastic.

With extruded bases, liquid poly is simply extruded, or molded, into shape. It glides less well, damages more easily on debris, and does not hold kick waxes for very long, although using a binder wax will help with that.
Extruded bases are easier to repair with a ptex candle than the harder sintered bases. Waxless patterns can easily be molded into extruded plastic material, and more modern base patterns reduce some of the drag associated with positive-type, raised extruded waxless bases.

Entry level skis, price point skis, non-race skis and etc. have lower manufacturing costs when extruded bases are used. Some manufacturers were not then, and some are not now, set up to manufacture skis with sintered bases, at least in quantity and continue to use extruded bases on their models.

A ski with an extruded base, waxable or waxless, or with a waxless center panel, uses that material as a cost-saving measure, imho.

This discussion has been around for a while.

Sintered Ptex bases first showed up on nordic racing skis in the late 1970s; Fischer was the leader in sintered base manufacture of waxed and waxless XC racing(RCS), and touring, (E99) skis as early as 1980 or 81, when all the other top brands, Kastle, Karhu, Rossi, Epoke, etc., were selling touring/tele skis with only extruded bases.
The famous phrase of the 1980's:"I really like my Epoke 900's, but the bases could be faster, they're Slow-Pokies".

If your waxless skis have a molded pattern of flukes or petals or scales, the bases are probably extruded.