Poster: A snowHead
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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The problem isn't having a single pass but the use of basegrinds to smooth out any cuts and grooves. Under his methodology you could easily have 50 passes by a lazy tech to remove a cosmetic scratch.
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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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Exactly.
I do like the horrible residue of the 250 passes……
I have had many core shots and divots - action: metal grip, pTex and wax.
I have a number of ‘very not flat’ skis some convex some concave - action: most of them ski fine, and I am not inclined to have them ground flat.
I have one pair of skis with a delaminating tail and thin thin bases - action: use them on rock ski days they show just how bad skis can get and still work
As you and others have said in the past….don’t oversweat the details.
I like to sweat the details regarding background knowledge, and then that often leads me to not worry about trivial and irrelevant details.
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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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My son, effortlessly the best skier in the family, will ski on anything. He once inherited a "worn out" pair, left by a guest in a chalet where he was cooking. Skied on them half the season, then one of them came apart in a spectacular crash somewhere up on the Grand Motte. He skied down to Val d'Isere, to meet me, on the remaining one, but didn't want to litter the mountain, so his young cousin carried the spare one down and sent a text saying "Nick on one ski, bit slow, be a bit late". You could put a fat finger between the top layer with the binding on and the layer beneath. He was quite regretful, had become fond of them.
He never knew whether the ski delaminated so spectacularly because of the crash, or he crashed because it delaminated.
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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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Dave of the Marmottes wrote: |
The problem isn't having a single pass but the use of basegrinds to smooth out any cuts and grooves. Under his methodology you could easily have 50 passes by a lazy tech to remove a cosmetic scratch. |
This ^ I always ask for them to go super light on the base but they still want it looking clean which is irrelevant on anything other than a race ski
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You'll need to Register first of course.
You'll need to Register first of course.
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The stone is only there to structure the base, nothing else. Putting loads of pressure on during a pass will cause loads of other problems, mainly the heat causes the base to concave a lot and you rail the ski. Two passes tip and tail should be enough for a well prepped ski.
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If you take a close look, the "tech" is only using the belt sander, not the stone, so he's really not taking any material off per pass, obviously after hundreds of passes he's managed to wear the base down, but nowhere near as much as a stone grind.........
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@KenX, I don't think he's a tech per se - It's "Angry Snowboarder" - he does board/product reviews.
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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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That video is total bollux. The belt being used looks pretty fine, somewhere in the 120-150grit range which would only ever be used for a fine finishing pass to remove the 'fuzz' left from using from previous lower grit belts. As the guy says, "the base is polished" and the shine can be seen, whereas when material is properly removed the finish that's left is matt and fuzzy. Plus there's no mention of the drum speed and feed speed etc which has a huge effect on the amount of material removed. Unfortunately they've speeded up the film so it's not possible to see the actually drum and feed speeds used.
On skis/boards that have concave bases shops would typically use a 60grit belt to flatten/impact linear structure (as many passes as 'necessary'), followed by an 80grit (as many passes as 'necessary'), followed by 1/2 passes with a 120-150grit belt. If the bases are pretty flat to start with then they'll skip the 60grit stage. The problem for the customers is that, especially with large resort shops that have fully automatic machines, is that the machines, instead of being set to take off the minimum amount of material, are set to tackle the worst case base in one pass so that the ski/board doesn't need to go through the machine again. The same applies to edge sharpening as well. Plus many shops grind skis/boards that don't need a grind at all but instead use the grind process to remove/dress down base repairs as it's a lot quicker than removing them by hand.
KenX wrote: |
If you take a close look, the "tech" is only using the belt sander, not the stone, so he's really not taking any material off per pass, obviously after hundreds of passes he's managed to wear the base down, but nowhere near as much as a stone grind......... |
As @orange says, the stone grind only imparts structure to an already belt sanded base. It's the belt work that takes off the vast majority of material and the stone only removes a fraction of the material to cut the 'tread'. Many shops don't have a stone grind machines as a belt grind gives a perfectly satisfactory linear structure and many of the shops that do have a stone grinder don't actually use it due the cost of replacing the stones, especially as Moonflex having been producing a patterned diamond belts for a number of years now which are quite a bit cheaper and which won't shatter in contact with the base edge angle.
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@rogg, hence the use of "inverted commas"..........
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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@spyderjon, what type of stone grinder do you use? The one in our shop could definitely kill a ski in 2 or 3 passes if not used right!
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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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KenX wrote: |
@spyderjon, what type of stone grinder do you use?...... |
I no longer have a stone grinder as it makes no commercial sense. I have an RoffB LM18 RPA R50 Active belt grinder for which I also have some Moonflex diamond belts for a non-linear grind. I've also previously owned a Wintersteiger Sigma and an old Reichmann. And on the rare occasion when a customer requests a specific grind (usually a high level racer) then I have a local 'wealthy' friend who, amongst his many toys, has a Montana CSB stone grinder.
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@spyderjon, ….well this is Snowheads at its best…discussion on a key topic which gets inside the leading craft knowledge and professional practice and makes it available to all members. I had always assumed that practice still was based on sanding to level the base and stone grinding to establish structure. Very interesting to know that Moonflex belts are making life easier for techs and improving servicing. And I am always worried about how the servicing machines are set up if I need a base service, since we have access to different shops in different villages and worry when a favourite tech moves or retires.
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You know it makes sense.
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rogg wrote: |
... It's "Angry Snowboarder" - he does board/product reviews. |
Oh, he's the guy I caught out apparently making up a review of a powder board some years back. He got quite angry when I reviewed his "review", which is presumably how that works.
I just double checked his review of my current board, and I'm struggling to believe he rode that either.
Some of the wording struck me as reminiscent of an actual board decent review of the same thing by Whitelines.
At least this video clearly shows he's actually used a base grinder, not just read the manual.
Quote: |
Moonflex diamond belts for a non-linear grind |
Non linear in what sort of way?
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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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phil_w wrote: |
......At least this video clearly shows he's actually used a base grinder, not just read the manual..... |
It this comment directed at me?
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Poster: A snowHead
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For me the video is anecdotal.
The number of passes is irrelevant, as with consumable abrasive surfaces theres a diminishing return as the sand / Emery / Glass paper becomes smoother and less abrasive with each pass.
I think the point of it is that we should not be worried about ski-techs gently passing boards on a belt a couple of times.
It's a bit hypocritical of me because I when I don't do my boards myself I take them to a shop where they do the job by hand.
On the odd occasion that they've been closed or I needed an emergency repair then the other places I've been have never destroyed any of my boards through servicing them, and have been perfectly ok afterwards. Though it doesn't compare to the hand job in terms of finish.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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spyderjon wrote: |
It this comment directed at me? |
Not remotely, at the Angry guy and the fact that his reviews of snowboards appear not to involve riding them.
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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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You need to Login to know who's really who.
You need to Login to know who's really who.
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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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It’s true that most places that grind skis will use various belts to do the bulk of the material removal and then finish on a stone.
However, if you want your skis ground in the best possible way, all (or at least most) of the work should be done on the stone. Belt sanding is cheap and lacks precision but offers an even finish on so many of today’s skis.
The finish from stone grinding bases properly is like comparing chalk with cheese to that of a sanded finish. Sadly, lots of people don’t know how to use a stone grinder (or belt sander for that matter) very well at all.
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