 Poster: A snowHead
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For those who don't know what 'Sintering' is (and that includes me) I looked it up and these seem like the relevant bits (courtesy of Wikipdeia).
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Sintering is the process of compacting and forming a solid mass of material by heat[1] or pressure[2] without melting it to the point of liquefaction.
Sintering happens naturally in mineral deposits or as a manufacturing process used with metals, ceramics, plastics, and other materials. The atoms in the materials diffuse across the boundaries of the particles, fusing the particles together and creating one solid piece
Plastics sintering
Plastic materials are formed by sintering for applications that require materials of specific porosity. Sintered plastic porous components are used in filtration and to control fluid and gas flows. Sintered plastics are used in applications requiring caustic fluid separation processes such as the nibs in whiteboard markers, inhaler filters, and vents for caps and liners on packaging materials.[4] Sintered ultra high molecular weight polyethylene materials are used as ski and snowboard base materials. The porous texture allows wax to be retained within the structure of the base material, thus providing a more durable wax coating. |
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| Gazzza wrote: |
Interestingly I never bother with a hot wax scrape cycle first. I just wax, leave overnight, scrape, repeat, then I'm set for my next week.
I've done a hot wax scrape once and I'm not convinced it made a huge improvement.
If I'm doing a ptex repair then I will just clean out the area to be repaired, using wax remover spray.
Otherwise I just wax, and go ! |
You'd be quite amazed by how much dirt comes off with a hot wax, especially after spring skiing!
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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The porous texture allows wax to be retained within the structure of the base material, thus providing a more durable wax coating
I was kind of hoping that someone would come up with some sort of evidence for porosity/permeability when as many people say that UHMWPE is non-porous and can hold neither wax nor water.
Strangely no pictures of these holes/pores or wax soaked bases on the internet.
Also - how does the wax soak into the base if the hot box isn't at the melting temperature of wax?
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You need to Login to know who's really who.
You need to Login to know who's really who.
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It's magic.
Or possibly diffusion.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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I would imagine to show the porosity you would need to be putting things under an SEM. Not many folk have those knocking around, let alone can take great pictures with them. The preparation for the sem is likely to destroy any wax remaining due to the drying needed to prevent any water vapourising in the vacuum.
There are also no RCT's of survival rates with and without a parachute on leaping from an aircraft.
I'm happy to keep on doing the useless waxing, is there any " evidence" it can do any harm?
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You'll need to Register first of course.
You'll need to Register first of course.
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Mr Charnley may know a thing about this, especially after the scrubbing brush salesman showed him this fancy plastic back in the day. Anyone know the relevance? My Grandad was lucky enough to benefit, and I've met a few people who worked with him directly.
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@glasgowcyclops has some pretty heavy duty microscopy at his disposal, think he even took a look at some edges post tune-up last year.
Get on it Bob! Need a white paper on ski base porosity and wax absorbtion fact vs fiction please.
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I know a man with more scopes than you can shake a stick at! This is hardly the type of thing he's interested about though.
I have a surgical operating microscope I use at work that does 24X mag with a camera attached. I'll take a ski to work next week and see what it looks like. It will have had the wax scraped off at chill factore tomorrow though. I will take a freshly waxed ski as a comparison. But at 24X I don't think we will see much. Be interesting to see how my edge tuning worked out though.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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I started this topic and there is a lot of anecdotal evidence, like ones skis are more slippery the next day after waxing and this maybe true but it could also be that the conditions have changed. There is disagreement whether the wax is absorbed on just sits on the surface, maybe it will last for a couple of runs or or stay for a season. Are the bases permeable or not, should I scrape while the wax is hot or leave it overnight. Should I squirt some teflon type stuff on my skis every few runs.
It would be nice to hear from a ski manufacturer about this subject. After all they are not concerned about wax sales or servicing particularly so they surely could be impartial.
I cant say that I'm now armed with the definitive answer. But as I said before, I'll carry on coz I like doing it.
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It is clear that polyethylene is non-porous but when you take powdered polyethylene and sinter it then you create a solid with lots of pores. This is the process used to create polyethylene filters so I think that a sintered ski base does contain pores and so waxing is useful.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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| tarrantd wrote: |
| It is clear that polyethylene is non-porous but when you take powdered polyethylene and sinter it then you create a solid with lots of pores. This is the process used to create polyethylene filters so I think that a sintered ski base does contain pores and so waxing is useful. |
Now that is interesting - but a couple of points arise from this:-
Anyone with extruded bases are wasting their time trying to 'soak' the base with wax - do folks know if their bases are sintered or extruded?
If sintered bases are powdered UHMWPE forced together under pressure at a lower temperature than the melting point of the polyethylene then i can see that there could be gaps between the molecules that you could fill with wax if you melted it on. The question would be - are the gaps big enough to do this - without compromising the strength of the base?
How far could you melt wax into the base with a waxing iron - and once it was in there - how would it ever get back out given that the bases are sitting on snow?
What would stop the wax continuing into the core of the ski - do some skis not have wooden cores?
Is the theory that the wax in the gaps anchors the surface wax better and stops it being removed by friction?
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You know it makes sense.
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A good guide is the heat on the topsheet when waxing.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Now that makes a bit more sense - that the wax can reduce the friction on the base - especially if the base has scratches on it or bits of dirt/dust stuck to it. The question would be how long does the wax last before its worn off and i think that depends on the snow and whether there is dust or other contaminants on the snow to do this. I dont believe that wax is held in the pores of the base and somehow gets pumped out to replenish the wax film on the surface of the base. The wax is in solid form when the ski is on the snow.
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Poster: A snowHead
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@rob@rar, am with you, see previous post.
@ropetow, yes, HDPE is sort of made of petrol, via a steam cracker and an HDPE plant
For all - UHMWPE and all other types of polyethylene are very different substances. However, they are all hydrophobic - and all to the same extent. Chemically, they're all pretty much identical. I can describe the differences if anyone wants.
Wax is softer than polyethylene. I'll lay money that it's a byproduct of polyethylene manufacture. Wax fills the microscopic holes and gives you a nice smooth surface that slides on snow. When that surface wears out, wax again. Slide smoothly again. Repeat as necessary.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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@WindOfChange,
If you want an anal article on bases or waxing just go to an XC site 
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