Resetting base bevels - best way to flatten skis

[Steve]

If the base edge is bevelled away from the base by even ½ degree, why would the structure pass impact it? Is it too deep to avoid the base edge?

 

[Dakine]

It is impossible to get a flat interface between two materials with differing moduli of elasticity with a grinding operation.
This is because the wheel puts a downward force on the base to make it cut and the materials spring back to differing degrees.
By using multiple light passes you can come close.
When things really have to be flat it takes a skiving (cutting) operation.
Precision machine tools have their ways hand scraped to eliminate high spots and get them flat within a few wavelengths of light.
Skis wouldn't ski differently if they were that flat.
As @Jacques can attest, the way to true flatness is by using a sharp steel scraper after the skis have been "flattened" structured.
Not many folks have the skill or patience to do this.
Certainly not me and I'm not rabid about really flat skis anyway.
I do run a steel scraper down the ski before waxing to find out just how base high they are and where.
According to @Primoz, even World Cup techs aren't this crazy about ski flatness.
Snow and ice are not flat either so good enough is good enough.

 

[Jacques]

It is impossible to get a flat interface between two materials with differing moduli of elasticity with a grinding operation.
This is because the wheel puts a downward force on the base to make it cut and the materials spring back to differing degrees.
By using multiple light passes you can come close.
When things really have to be flat it takes a skiving (cutting) operation.
Precision machine tools have their ways hand scraped to eliminate high spots and get them flat within a few wavelengths of light.
Skis wouldn't ski differently if they were that flat.
As @Jacques can attest, the way to true flatness is by using a sharp steel scraper after the skis have been "flattened" structured.
Not many folks have the skill or patience to do this.
Certainly not me and I'm not rabid about really flat skis anyway.
I do run a steel scraper down the ski before waxing to find out just how base high they are and where.
According to @Primoz, even World Cup techs aren't this crazy about ski flatness.
Snow and ice are not flat either so good enough is good enough.

Yes, as I state in a few of my videos, I too do not care about a ski being perfectly flat!
Reasonably flat is good.
It's easy to flatten out a convex base, but near impossible to flatten a concave base with a steel scraper.
There are a few really fancy steel scrapers out there somewhere that will cut even steel. I have never had one, so don't know for sure.
The SkiVisions deal has a steel bar along with the stones, so maybe.

 

[GregK]

I’ve had issues with stone grinder residue left on that has stained the top sheets on skis. Ski top sheets have clear coat finishes similar to a car so using a car wax with chemical cleaners or mild abrasive polishes mixed in will remove any stains.

Look for car waxes with “cleaner wax” “removes small swirls or scratches” in the description to let you know it has some chemical cleaners or polish mixed in them. Or if you have car polish on hand, use it first to remove any stains then follow with a wax/sealant/coating to protect after polishing. You shouldn’t need something as strong as a compound unless you were looking to remove scratches on the top sheet.

Use my Detailing polishers all the time on top sheets to remove scratches or stains.

 

[Dakine]

Yes, as I state in a few of my videos, I too do not care about a ski being perfectly flat!
Reasonably flat is good.
It's easy to flatten out a convex base, but near impossible to flatten a convex base with a steel scraper.
There are a few really fancy steel scrapers out there somewhere that will cut even steel. I have never had one, so don't know for sure.
The SkiVisions deal has a steel bar along with the stones, so maybe.

A Ski Vision with a burred cutter is a wicked beast.
Not for amateurs.

 

[Scruffy]

A Ski Vision with a burred cutter is a wicked beast.
Not for amateurs.

What's your technique for burring the Ski Vision steel bar?

 

[Jacques]

Yes, as I state in a few of my videos, I too do not care about a ski being perfectly flat!
Reasonably flat is good.
It's easy to flatten out a convex base, but near impossible to flatten a convex base with a steel scraper.
There are a few really fancy steel scrapers out there somewhere that will cut even steel. I have never had one, so don't know for sure.
The SkiVisions deal has a steel bar along with the stones, so maybe.

Oh darn it! I said convex twice! In the second time I meant to say CONCAVE! My bad! Hard to flatten concave with a scraper!
I was too late coming back to edit.

 

[dbostedo]

Oh darn it! I said convex twice! In the second time I meant to say CONCAVE! My bad! Hard to flatten concave with a scraper!
I was too late coming back to edit.

I fixed it.

 

[Sibhusky]

I knew what you meant.

 

[oldschoolskier]

I’ll confirm @Jacques comment re flatten concaved skis with a scrapper not possible. Stone or belt yes as steel needs to be removed. Scrappers for doing machine beds for flatness would gouge the bases as they function differently compared to card scrappers used by skiers. So the only manual method is filing and in this method a draw filing technique is used, sort of looks like scraping. Trick is not to flex the file while doing this thereby creating new problems. Do not cross file as you will drive metal shavings into the bases.

Belt sand relies on operator experience and skill not to over pressure the ski not to create problems and create a good finish.

On stone grinders because it machine controlled (cnc) higher pressures and speeds can be used however fluid must be used. The fluid used in a stone grind is to ensure three things. Clearing scarf from the cut, to prevent clog of the wheel which in turn generates heat (bad), removes heat generated by the cutting action (bad) and finally lubricates grind action to keep grind action cool (good).

This fluid is sophisticated mix of chemicals and oils to do all these things, however are not always good (read as definitely really bad) for a ski if allowed to soak in.

A good operator should (must) remove the excess (at minimum) to the point that little noticeable moisture is left (not enough to stain, but maybe a residue) and then give a wipe down (which ideally drys and leaves a clean ski). If you get your skis back in any other conditions I would seriously consider a different shop and they really have no clue on what they are doing thereby potentially harming your skis life.

 

[Dakine]

What's your technique for burring the Ski Vision steel bar?

I square up the bar by working it through a series of wet sandpaper grits on a piece of glass till the edge is sharp.
Then I burr it by clamping it in a vice and running a piece of carbide rod down the length at a 45 degree angle (usually) with heavy pressure.
You won't believe how a properly burred edge will cut.

 

[Steve]

I have a carbide rod I run my steel scrapers down after sharpening them on a file mounted in a vice.

Never thought of putting a burr on my Ski Visions bar, thanks!

How do you maintain the stones?

 

[Scruffy]

I square up the bar by working it through a series of wet sandpaper grits on a piece of glass till the edge is sharp.
Then I burr it by clamping it in a vice and running a piece of carbide rod down the length at a 45 degree angle (usually) with heavy pressure.
You won't believe how a properly burred edge will cut.

Cool, thanks. I bought the green stone that is suppose to be used to burr it up, but it doesn't seem to do much. I'll try your method.

 

[Dakine]

I have a carbide rod I run my steel scrapers down after sharpening them on a file mounted in a vice.

Never thought of putting a burr on my Ski Visions bar, thanks!

How do you maintain the stones?

I don't use the stones.
A good operator on a Winterstiger is much better for that.
But, if you take your skis in flat and get a grind that is only as wide as the waist of the ski and then file and hone, that's the best an amateur can do.

 

[CalG]

I don't use the stones.
A good operator on a Winterstiger is much better for that.
But, if you take your skis in flat and get a grind that is only as wide as the waist of the ski and then file and hone, that's the best an amateur can do.

This is the new goal

WC base structures

Nice thing about a sunny race (at last!) and high-def cameras is that sometimes you can catch a glimpse of the ski bases in the finish area. Here is Head (Sara Hector) and Völkl (Alice Robinson). Structure looks overall narrower across the base on the Head skis.

www.pugski.com

Don't try this at home!

But we will!

;-)