Viable at-home alternative to grinding?

[sparty]

So with the number of skis in my quiver and my wife's, trying to keep everything flat is a bit of a challenge—the reliable local shop charges $50 per grind, and that adds up rather quickly. I can get the guys doing race skis to sneak my race skis through occasionally, so I'm trying to come up with a solution for the rest of the skis (groomer, all-mountain, touring and soon kids' skis). I tried just getting stuff flattened and blanked at another local shop that actually offered standalone flatten & blank service, but that's still $30/pair, and the results weren't exactly encouraging—the skis came back closer to flat, but at least the two pair of groomer skis were still concave across the shovel. The touring skis are wide enough that I need to get a longer true bar to be sure, but I can guess.

I did pick up Toko base-angle guides this year, so I have no problem resetting the base edges as long as I can get the skis flat (and, in the case of significant rock damage, get through that). With the skis I had flattened and blanked, I used sandpaper to impart a little structure, cleaned up as best I could with a metal scraper, Scotchbrite, and brushing (before doing normal base-prep wax/brush cycles). The overall results seemed pretty good—the skis glide and turn well—but $30/pair is hard to swallow if the skis are coming back truly flat.

I've been considering trying to pick up a Ski Visions base planer and the associated accessories, but my dad had one of those years ago, and I don't recall getting the result I was hoping for. I was, however, a teenager at the time and I've tuned a lot of skis since, so I'm hoping that the tool is good and it was user error. I'd also be open to other suggestions, but the basic goal is to be able to maintain flat bases on non-race skis.

 

[KingGrump]

If I start with a flat p-tex base. Keeping the p-tex base flat is usually not the issue for me. The base bevel growing pass what I like is usually the real issue. The issue of growing base bevels is marginal in softer snow. Gets to be a hand full when the snow gets firm.

 

[sparty]

If I start with a flat p-tex base. Keeping the p-tex base flat is usually not the issue for me. The base bevel growing pass what I like is usually the real issue. The issue of growing base bevels is marginal in softer snow. Gets to be a hand full when the snow gets firm.

I've had both issues on different pairs of skis, although I have to admit that I'm not 100% sure the convex skis were ever truly flat; I'd like to be able to address both convex/concavity issues as well as over-beveled edges. I'm assuming that if I can get a ski to truly flat, I can reset the bevels appropriately.

 

[Scruffy]

The SkiVissions base flattener tool works, but it's a sh!t ton of work to flatten a ski or bring a flat ski down enough to reclaim the base edge bevel. I've had one for like 20 years now and use it every year on at least one or two skis. I've purchased the newer style stones and new metal bars. Turns out that the Ptex is pretty tough stuff. You'll need to put a burr on the metal bar to scrape effectively, but the bar, she is very hard. Much easier to get a burr on a BACHO scraper. If you've got a lot of time and want an upper body workout, go for it. If you're thinking a few strokes of easy planning like a wood plane, yeah no. I use the structure stones to removes some ptex, and then the metal bar, or sometimes I just skip the metal bar and use a BACHO after the stones.

YMMV, but... if you have a lot of time on your hands...

 

[crgildart]

There was a time when people filed their skis flat every other week with a bastard file. Belt or stone grinds were something only the top level racers had done regularly.

I've done this before... about 15 seconds on each ski with a handheld belt sander. Then finish it smooth with a tuning file, set your edges, and see if it's worth saving a few dollars. Ruining a $600 pair of skis in an effort to save $50 might not be the desired result though. Unless you're really good with sanders, routers, etc I recommend you just file or pay the money for a grind.

 

[KingGrump]

I've had both issues on different pairs of skis, although I have to admit that I'm not 100% sure the convex skis were ever truly flat; I'd like to be able to address both convex/concavity issues as well as over-beveled edges. I'm assuming that if I can get a ski to truly flat, I can reset the bevels appropriately.

I think the key is to start off with a flat ski. The new auto feed machines with a good tech usually yields a good job. My "local" guy will do the base bevel for $5 more. I confirm the base flatness with couple different true bars. I have a 14" bar for the wider skis.
On the road, I do not trust the techs with the base bevel so I usually will have the shop flat grind the ski. I like a margin type structure so the base structure do not get on the base edge. Many shops screws that up.
If it is a good snow year out west, I can get 50 days out of a grind. Bad year - about 30 days. New England, the base bevel can be gone in couple weekends.

 

[Tony S]

I think the key is to start off with a flat ski. The new auto feed machines with a good tech usually yields a good job. My "local" guy will do the base bevel for $5 more. I confirm the base flatness with couple different true bars. I have a 14" bar for the wider skis.
On the road, I do not trust the techs with the base bevel so I usually will have the shop flat grind the ski. I like a margin type structure so the base structure do not get on the base edge. Many shops screws that up.
If it is a good snow year out west, I can get 50 days out of a grind. Bad year - about 30 days. New England, the base bevel can be gone in couple weekends.

I am just super conservative with doing anything to the base edge at all. Very light diamond stone with a guide, no cheating, if there are base-side burrs from rocks or whatever. Otherwise side edge work only.

But yes, you need a really good pro tune to start with. When you find someone good, insist on having that person do the grind, and make it worth their while.

 

[Doug Briggs]

...
Much easier to get a burr on a BACHO scraper. If you've got a lot of time and want an upper body workout, go for it. If you're thinking a few strokes of easy planning like a wood plane, yeah no. I use the structure stones to removes some ptex, and then the metal bar, or sometimes I just skip the metal bar and use a BACHO after the stones.

YMMV, but... if you have a lot of time on your hands...

And tough, strong hands.

 

[KingGrump]

Base flatness is probably way over emphasized. If the base is flat for about 1" along the edge, it's good enough for me. Very seldom do I ski with my ski dead flat on the snow. A small concavity is OK. The Grand Canyon, NO.

Base edge bevel is probably one of the most important tuning parameter to get right. Way more important than the side edge bevel.
Case in point. @Lady_Salina and @Old boot bought two new pairs of Head iRally to VT couple weeks back. They left their skis at W/B when they abandoned ship last March. Both pairs were mounted new out of the wrapper. One pair was not skiable. Spooky & hooky. I loaned her a pair of S9 for few days.
Before she left, I put a 1/3 tune on her Head iRally. The base bevel varied from 0 to 1 degree along the ski. It was atrocious. She called me and let me know they now skied like a dream. Factory tunes often suck.

 

[Dave Marshak]

I use the structure stones to removes some ptex, and then the metal bar, or sometimes I just skip the metal bar and use a BACHO after the stones.

BACHO?

dm

 

[KingGrump]

BACHO?

dm

A brand of steel scraper.

 

[Doug Briggs]

aka Cabinet Scraper.

That's what we used in the good old days. Square off the edge and put a burr on it with round shaft screwdriver as a burnishing tool.

 

[motogreg]

I too have struggled with my local shop to get bases flat.....it seems like flattening would be the first thing they would do, but after 2 trips my Mantras are still rail high.

 

[KingGrump]

I too have struggled with my local shop to get bases flat.....it seems like flattening would be the first thing they would do, but after 2 trips my Mantras are still rail high.

There is something wrong with their machine or process.

 

[crgildart]

I too have struggled with my local shop to get bases flat.....it seems like flattening would be the first thing they would do, but after 2 trips my Mantras are still rail high.

And rail/edge high is way easier to resolve than base high is..

 

[Noodler]

There is something wrong with their machine or process.

I agree.

@sparty - are you certain the base flattening service was provided by stone grinding and not a belt sander? Some shops will sell "base flattening" as a service, but they do it using a benchtop belt sander instead of a stone grind. Belt sanding is bad news for skis.

 

[sparty]

I agree.

@sparty - are you certain the base flattening service was provided by stone grinding and not a belt sander? Some shops will sell "base flattening" as a service, but they do it using a benchtop belt sander instead of a stone grind. Belt sanding is bad news for skis.

I didn't ask. I made the assumption that they were using their fancy, largely automated Wintersteiger.

 

[Noodler]

I didn't ask. I made the assumption that they were using their fancy, largely automated Wintersteiger.

In my experience, stone grinding is called a "stone grind" whereas base flattening sold as a "base flattening" is rarely a stone grind. You need to specifically ask for stone grinds.

 

[Doug Briggs]

You can't run a ski through an automated tuning machine that uses a stone, succeed in flattening the base and have high base edges. Can't do it. You could on a belt sander.

If you flatten a ski and the edges are high, your tech's skills are suspect. Seeing crates of bananas would give you a clue to walk out the door.

 

[NE1]

There is something wrong with their machine or process.

...or their operator...