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base structure: fact or crap?

post #1 of 15
Thread Starter 

Hi, Guys,

 

This may be a newbie question -- as I'm a tuning newbie -- but I'm wondering if there is any (unbiased) empirical/scientific evidence supporting imparting structure on a ski base that is later waxed.

 

I know that wax layers can also be imparted with structure, which I'd think would last a few hundred yards/meters -- maybe a portion of a ski race, which could be material.

 

But as for base structure, I'd wonder how a) it could make a difference initially with wax on top, and b) it could make a difference once the wax gets worn down, b/c I'd think the surface wax would be evenly abraded away, leaving any structure channels clogged with the remaining wax.

 

I've always wondered about this, and now that I'm building out my tuning kit I've noticed that while there are plenty of products and opinion about structuring, there does not seem to be a clear consensus on what works. This is at least a yellow flag to me, but I thought I'd ask here in case evidence or studies exist (studies sans industry ties, which might be unrealistic, I realize).

 

Should I skip the structure brushes?

 

James

post #2 of 15

fact

 

As for structure brushes, I'm not sure what you are looking at. Something like a very aggressive barbecue brush can add structure for skiing in spring time snow and is really worth having if you will be skiing in very wet springtime slop.

post #3 of 15

Fact.

Brushes remove the wax between the structure grooves, and leave wax in the pores of the sintered P-tex base material.

post #4 of 15

fact

 

Microscopic grooves in the base (structure) keep the base from sticking on the snow via water suction.

 

I have skied on skis with really messed up structure and they were almost unskiable even on green terrain.

 

When you wax, you scrape and brush most of the wax off - the structure is still in effect.

 

A skivisions base flattening tool with a ruby stone is good for imparting structure.  The structure is mostly created during stone grinding, a steel or brash brush may open up the structure, but you need to use a rilling tool, or a stone on the base to really create structure.

post #5 of 15

I think you have the right idea except you are missing one part.  The wax is ironed into the base and you scrape the excess off.  This wax bleeds out as you ski, lubricating the surface to prevent oxidation and enhance glide.

 

Here is more info on ski base structure.

post #6 of 15

I can tell you from personal experience what happens when your ski bases don't have a structure.  Last year, the first day of the ski season, I was so busy with a new real life job, that I went skiing with the coat of storage wax on my skis (not even a scrape).  It was a Maplus race base (purple), which is a relatively hard wax, and the conditions were a mixture of warm natural and man-made, with the man-made still in the form of machine-powder patches.  Many times during the day, I came very close to going over the "handlebars."  By the end of the day, there was still enough wax on my skis to scrape of.  The idea that you don't need to scrape because it'll come of on the first run was completely debunked that day, under those conditions.  It would've been a good Mythbusters episode for all the 17 people who'd manage not to fall asleep.

 

The purpose of the structure is to break the surface tension between the bases and the surface of the snow.  Perfectly smooth, unstructured bases, will cling like glue to wet snow.  Structure breaks up the surface tension.

 

There's a lot of science and art about what structure is optimal for what type of snow.  For most non-pros, this is an overkill.  I wax/tune my skis every weekend, and brush the wax out religiously (except the faithful incident mentioned in the first paragraph).  I don't bother with my own structure tools, and the only time I do anything about the structure is when I get a base grind, but usually because of flatness or excessive repairs.

 

I'm of the school that a good structure on the bases is like fine wine.  With regular waxing/scraping/brushing it matures and becomes faster.  A freshly ground bases will take a few cycles of waxing/scraping/brushing/skiing to become slick again.  I have hard time believing that FIS level skiers would actually regrind the bases for the spring portion of the WC circuit.  Once you have a fast gliding base, don't mess with it.

 

I do most of my brushing with horse hair, nylon or bronze brushes.  Steel brushes are very aggressive, and I'd recommend staying away from them, until you develop the confidence.  It's very easy to over do it.  Do not experiment on an expensive pair of skis.

 

Bottom line: brushing to expose the structure after waxing, is very important, or you significantly give up performance.  Obsessing about the structure, unless you're a pro, is a waste of time.

 

Finally, regular waxing protects the bases against wear'n'tear.  I have no proof of this, but my own experience, and experience of friends is that ski bases saturated with wax are more resilient to nicks and gouges.  I have skis with 50+ days of skiing without a slightest nick in the bases.  (Lawyer disclaimer: it's not Kryptonite - if you hit a rock, you'll leave some ptex behind, no two ways about it).

 

My $0.02

post #7 of 15

That reminds me of the guy that bought 30 packs of ptex from me (that's 300 sticks).  After he got them he called with a question and I asked him what he did with them.  He said that he was going to use them to fill in his son's and his son's friends snowboards and then buff them down so they would be smooth as glass.  I tried to tell him as nicely as possible that that was exactly the opposite of what you wanted (for the reasons mentioned by others above).

post #8 of 15

Yes, base structure matters.  Your favorite backshop tech should be able to talk to you about how he dresses the stone on the machine.  The crosshatches on your base should form elongated diamonds during the cold months and shortened diamonds (like the tread on a tire) for warm months with wet snow.  At least he should be able to tell you about that

post #9 of 15
Thread Starter 

Guys, your responses have been very helpful -- thanks a bundle. Seems like in a nutshell, the idea is that you really ski on the p-tex with just a thin layer of wax (oozing out of the interstices?), vs. skiing on a big layer of wax.

 

I get this very clearly now.

 

To wander a little -- but related to structuring tools -- I do have a SkiVisions base flattener, but I've held off on using it yet.

 

Last winter I used a cheap file and quick, sloppy technique (i..e, filing with skis standing up, in the cold, manually pulling back brakes) to "set" the base angle -- note that I've read much since then and would NEVER try this again -- but I'd like to use a better file guide, more time, and a 100-grit diamond stone (or 300?) to at least even out my rush-rush edge job. Long way of saying that it would seem like I'd want properly flat bases before messing with the base geometry, b/c the base guides the file guide.

 

(And then I plan to mostly just do the sides after I get the base right.) Just a ramble, and thanks again for the kind posts,

 

James

 

post #10 of 15

Exactly; the wax is in the ski, not on the ski, so to speak.  And your bases are not made of PTex, that is simply to fill the holes.  Your bases from the factory are sintered (if your skis are worth anything), which allows the wax to "sink in."  As for base flatteners or planers, they work best as paperweights for your desk or possibly tire chocks if large enough.

post #11 of 15

mde, I agree with everything you say, but do have to say that I have had good success using the Ski Visions tool with a stone, not a blade.  Kind of like a very light stone grind.  Very light, just smooth it out a little.  What do you think of that?

post #12 of 15



 

Quote:
Originally Posted by Doctor D View Post

I think you have the right idea except you are missing one part.  The wax is ironed into the base and you scrape the excess off.  This wax bleeds out as you ski, lubricating the surface to prevent oxidation and enhance glide.

 

Here is more info on ski base structure.



Doctor D,

 

Here is a related question.  For a recreational skier (let's leave racing aside), would there be a noticeable performance gain from putting a different soft-snow structure into a sintered base during the spring?  Or is just using an appropriate wax good enough?

post #13 of 15
Quote:
Originally Posted by SkiMangoJazz View Post

mde, I agree with everything you say, but do have to say that I have had good success using the Ski Visions tool with a stone, not a blade.  Kind of like a very light stone grind.  Very light, just smooth it out a little.  What do you think of that?


I can imagine a stone would temper it some.  My gripe is that unlike a real grind, where the drivewheel puts equal pressure along the ski as it passes over the stone at a constant speed, a hand planer is not consistent enough (downward pressure or speed) to create an acceptable finish, although for smoothing out small spots or even just taking away excess filler, I can see it being useful.  Although, for all the skiing it looks like you do at the BEast, your skis should have that "natural" stonegrind by now

post #14 of 15
Quote:
Originally Posted by mdechristopher View Post


 Although, for all the skiing it looks like you do at the BEast, your skis should have that "natural" stonegrind by now


True dat.

post #15 of 15


 

Quote:
Originally Posted by quant2325 View Post



 



Doctor D,

 

Here is a related question.  For a recreational skier (let's leave racing aside), would there be a noticeable performance gain from putting a different soft-snow structure into a sintered base during the spring?  Or is just using an appropriate wax good enough?

 

Yes, anyone would notice the difference in wet warm snow because of the suction effect from the excess water.  I think structure and brushing are just as important.

 

Marc
 

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