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How to get a razor edge?

post #1 of 43
Thread Starter 
It takes a lot of work with dozens of passes of each grit diamond stone to get an absolute razor edge on slalom skis. Should it be taking this much? I progressively get finer with the stones, and a LOT of black stuff comes off (using water always). It just takes so, so many passes to get it sharp.

Should I be sharpening the base angle as much as the side angle?
post #2 of 43

LOOK at the edges !  Use  10X assist. 

Black is NOT the color of metal removal.

post #3 of 43
i disagree. The removed metal left on the stone looks a very dark gray when wet.

But bigger picture, no do not file/stone the base.
If an edge is really dull, it makes sense to file than stone forever. But I think that is rare. (Others will disagree. Racers file frequently.)

You know when you are done with a stone by sound and feel. If your edges have hit something, the first few passes will sound scratchy. Then the sound goes away. A few more passes and the feel changes -- smoother and less resistance. You are done, or switch to a finer grit.
post #4 of 43
Thread Starter 
Okay. But how much should it take to get a razor edge with no dullness?
post #5 of 43
First, a disclaimer. I don't race. I like a sharp edge, but I don't obsess about it (except for new skis).

For normal routine wear, doing a touch up after a couple of ski days this is my routine (I'm going from memory, it would be more accurate if I kept track as I did it.)

Start with extra coarse, 100 grit. Find any hits (rough spots) by feel with my fingers. Do short fast strokes at those spots till they smooth out, maybe ten reps. Do one pass of short overlapping strokes (wiggle my hand rapidly as I move down the ski), or maybe two. Then maybe five-ish long passes down the whole ski.

Then five-ish long passes with a fine grit, and five-ish with extra fine.
Total time less than ten minutes per edge.

Isopropyl alcohol works better than water - lower surface tension. I use a laboratory squirty bottle (makes a stream of liquid come out a fine pipe when you squeeze the bottle). When I wet it, I rinse away the debris. If there is a lot, I clean it with a couple scrubs with a nylon brush without removing the stone from the guide. Mine I got at the hardware store, I think it is meant for cleaning brake parts, but it is about toothbrush size.

One other thing I noticed is that the right clamps make the job easier. Originally I used a spring clamp I happened to have lying around but it was too big. Got better ones at Harbor Freight when I happened to see them -- small but strong grip.

If a rock hit is particularly bad, I will smooth the base with an stone (a real stone, not diamond). Very minimally, using just finger motion, just at the hit. Not like the way you do the side edges.

Also note the isopropyl you get from the drug store is already a water-alcohol mix. Get the weakest you can find -- usually 70 percent. Not the 90.
post #6 of 43
oh, and if the deposit on your stones is the same color as your sidewalls, you need to find the sidewall prep thread.
post #7 of 43
I have a U16 racer at home and do plenty of ski prep. If you want your edges race sharp, you need a file like the Swix World Cup or similar. After the file use two-three different diamonds going frim coarse to fine rto make the edges shiny. Don't touch the base with anything but a fine stone/diamond and rubber stone.
post #8 of 43
Thread Starter 
Quote:
Originally Posted by Karlsson View Post

I have a U16 racer at home and do plenty of ski prep. If you want your edges race sharp, you need a file like the Swix World Cup or similar. After the file use two-three different diamonds going frim coarse to fine rto make the edges shiny. Don't touch the base with anything but a fine stone/diamond and rubber stone.
Great. Thanks. Filing is usually not done often, most people suggest once a season. How often do you file in order to get ice-ready edges? Won't the filing greatly shorten the life of the ski?
post #9 of 43
Filing does shorten the life of a ski, but it's the only way to get them really sharp. I file after 5-6 trainings and diamond after each. Or if I know the course is going to be extra hard due to weather and for races. Say the fiile comes out 6-7 times every season for SL and GS and a couple of times for SG. The edges are not an issue for the latter, and give SL:s and GS skis a four-five season life span. But at youth years only kept one season (sometimes even less) and the sold on to kids in the younger groups.

Edit. And for me personally, I file my own skis perhaps after 7 days, diamonding them after each 2-3 days. So filing 2-3 times a season. I get 20-25 days. Would like more...
post #10 of 43
Thread Starter 
Quote:
Originally Posted by Karlsson View Post

Filing does shorten the life of a ski, but it's the only way to get them really sharp. I file after 5-6 trainings and diamond after each. Or if I know the course is going to be extra hard due to weather and for races. Say the fiile comes out 6-7 times every season for SL and GS and a couple of times for SG. The edges are not an issue for the latter, and give SL:s and GS skis a four-five season life span. But at youth years only kept one season (sometimes even less) and the sold on to kids in the younger groups.

Edit. And for me personally, I file my own skis perhaps after 7 days, diamonding them after each 2-3 days. So filing 2-3 times a season. I get 20-25 days. Would like more...
Thanks. After a day of freeskiing on icy conditions my edges go from a razor to slightly dull, and it takes dozens of diamond stone passes in each grit to get it close to that razor again. Should it be going like this? What is the process you use to get ice-ready edges every day?
post #11 of 43
Ski prep is hard work 😃 Sounds like about what I'm doing. Perhaps not 12 passes, more like 8-10 passes with three different grits. But you won't get the edges completely back to were you began (considering they were fresh). After a few days (depending on conditions, needs and skiing style) you have to file to get them sharp.
post #12 of 43

I touch up my edges and wax the skis after each 5 half days of skiing during the season. I average skiing 125 days each year. I have had great results using the Holmenkol Crystal Finish File 4 inch 15teeth per CM from Artechski.com. This fine tooth file permits me to sharpen the side edge of the skis weekly, removing very little material from the edge. I follow up with 10/12 passes using two grits of diamonds (200/600) and several passes with an Arkansas Fine Stone. This proactively keeps my edges very sharp, not needing to play catch-up with dulling edges. Use of this file has shown very little loss of edge width on the skis even after a couple years of tuning/skiing. I only use the more aggressive files to set the initial edges or heavy damage. As suggested by others, I only touch the base edges in order to remove bigger nicks. 

Holmenkol Crystal Finish File
Extremely sharp, straight, & long lasting non-chromed file.

Used for very fine removal of edge. Has 15 teeth per cm for professional results.

Superb for base beveling, as the tooth height is the shortest, yielding the most accurate base bevel when used with Holmenkol base edge file guides.

post #13 of 43

I file (or now use the Swix EVO electric tuner) a few times a season, maybe every 10-15 days, possibly less if it's been very icy.

 

If I can I debur with stones every day or two, at the most I'll go three days.

 

Ski in the East.  Don't race.

 

I'm not worried about losing too much edge.  What am I a curator?  Ski the edges and bases off of them.  They'll make more skis.

post #14 of 43
I too use two different files - Swix chrome WC 15 and 20 tpc fine cut. 15 doesn't come out every time.
post #15 of 43

Never touch the base edge unless you just finished stone grinding, flattening the base, etc. Be diligent about wiping water and snow off the skis at the end of the day so you never have to remove rust from them. Getting sharp side edges has always been a ton of work for me doing the whole stone progression thing. I want to upgrade to an electric edge sharpener but don't want to pay $100 per wheel. Some day...

post #16 of 43
Also want to add an extremely important step: shave off sidewall! Inme the sidewall is often the problem when you don't manage to get the edges race sharp. Make sure to get rid of a healthy bit before you start working on the edges. I use a sidewall tool from ... name escapes me. But I've tried a few different makes and they all worked. Swix might be the one I preffer.
post #17 of 43
I agree, sidewall prep is key, otherwise your tool rides on the plastic sidewall instead of the edges. I'm sure there are threads about that somewhere.

Racers need to file frequently, but they need the absolute sharpest edge possible. Infrequent filing with frequent stone touch-up is good for the rest of us, even on real ice.
post #18 of 43

I sharpen my skis almost every day. A few years ago I switched to an electric edger. So much faster and you can easily edge the skis more than 100 times. Razor sharp each time.

Saves a lot of time and in addition the heat makes the edges hardened, which makes them more durable.

post #19 of 43
It they are more durable, then why are you sharpening every day? Are you racing every day? Seems unlikely.
post #20 of 43
Real race skis have softer metal to start with.
Quote:
Originally Posted by sibhusky View Post

It they are more durable, then why are you sharpening every day? Are you racing every day? Seems unlikely.
post #21 of 43
Quote:
Originally Posted by Karlsson View Post

I have a U16 racer at home and do plenty of ski prep. If you want your edges race sharp, you need a file like the Swix World Cup or similar. After the file use two-three different diamonds going frim coarse to fine rto make the edges shiny. Don't touch the base with anything but a fine stone/diamond and rubber stone.

Using a Gummi stone on the base edge is not a good idea. It is too soft and a little bit of the rubber laps over the edge and in essence you dull the edge.

 

You should just use an 18--20 TPC file on the base and then hard Arkansas stone or surgical stone to polish it.  

 

 

I use a blue hard gummi to dull the ski ahead of the contact points on tip & tail and then as the very final step in tuning at a 45 degree angle with ABSOLUTELY NO PRESSURE one pass down the edge point.

post #22 of 43
Quote:
 I sharpen my skis almost every day. A few years ago I switched to an electric edger. So much faster and you can easily edge the skis more than 100 times. Razor sharp each time.

Saves a lot of time and in addition the heat makes the edges hardened, which makes them more durable.

 

 

What model did you get? If you were to do it again would you get a different one?

post #23 of 43
Quote:
Originally Posted by Atomicman View Post

Using a Gummi stone on the base edge is not a good idea. It is too soft and a little bit of the rubber laps over the edge and in essence you dull the edge.

You should just use an 18--20 TPC file on the base and then hard Arkansas stone or surgical stone to polish it.  


I use a blue hard gummi to dull the ski ahead of the contact points on tip & tail and then as the very final step in tuning at a 45 degree angle with ABSOLUTELY NO PRESSURE one pass down the edge point.

I use a gummi stone to clean the base edge (I actually do that to the side too). Sometimes there are some blackish residue that get stuck - we ski a lot on dirty snow I guess. Then a fine stone. Then go to the sides. Then maybee deburr with gummi as you describe. Haven't really had any trouble with hangung burr. Never dull the edges. Sharp from tip to tail.
And never use a file on the base unless setting the edge angle after a grind. Or if I would want to alter to a gentler angle.
Edited by Karlsson - 3/14/17 at 3:27am
post #24 of 43
Quote:
Originally Posted by Karlsson View Post


I use a gummi stone to clean the base edge (I actually do that to the side too). Sometimes there are some blackish residue that get stuck - we ski a lot on dirty snow I guess. Then a fine stone. Then go to the sides. Then maybee deburr with gummi as you describe. Haven't really had any trouble with hangung burr. Never dull the edges. Sharp from tip to tail.
And never use a file on the base unless setting the edge angle after a grind. Or if I would want to alter to a gentler angle.

To each his own, but diamond stones are much more effective at removing anything and are hard enough to polish at the same time. The 45 degree gummi procedure is NOT how to remove the hanging burr. 

 

 

That must be done with a hardstone flat against the base edge steel matched to the base edge bevel.  

post #25 of 43
Quote:
Originally Posted by mjp5 View Post
 

 

 

What model did you get? If you were to do it again would you get a different one?

I have a wintersteiger discman 2, and in the race club I also have access to a snowglide pro.

 

Pretty happy with both. The Snowglide is a bit better but much more expensive and also a bit questionable quality.

 

If I would buy one today I would also consider the Swix. It looks like good value for the money.

 

An additional advantage with a good machine is no burr. I have a 100x mini microscope that I use to inspect the edges, and it is incredible how clean the edge is.

post #26 of 43

The best way I have found to get a razor edge on a pair skis, in one sentence, was to learn to tip my skis purposefully, cleanly, equally and progressively starting with full frontal pressure that travels back along the ski, keeping my legs damp (strong but absorbant) and my skis weighted throughout the entire turn using flexion and extension to absorb all vertical impact (both positive and negative) for a vertically steady CoM while maintaining outside ski pressure dominance and fully active participation of the inside ski. I have also toiled with many of those stone and file thingies mentioned above. The first part, though, is much more fun to work on.

post #27 of 43

File is the only way to get a razor sharp ski, diamond stone effectively polishes and work hardens the edges after filling which provides the last little bit of sharpness but more importantly increases the edges durability ( will stay sharper longer), if you use diamond stones after every ski this would increase the window of days on snow between fillings.

 

I find that after filling the areas that require sharpening ( I only file the dull part of the edge as there is no need to resharpen sharp areas) to a razor sharpness I then use two diamond files medium and fine (sometimes I'll add exta fine) with about two rounds of 4 to 5 passes each with a cleaning of both the diamond stone and the edge and full relubrication between rounds of passes.

 

This year I started using SVST Secret Sauce instead of water for a lubricant and it has upped the game. To save cost, I spray edge with water and the secret sauce directly on the diamond stone.

 

Also, I would suggest buying only the highest quality guides, diamond stones, and files. I wish I never wasted money on the cheap stuff, year in and year out I have been replacing stuff with top of the line and getting better results with each upgrade. case and point my diamond stones, upgraded from $15 KUU stones to the $70 each Swix top of the line stones and it was like magic :)

 

hope that helps

 

Matthew

post #28 of 43

Actually a 100 or 200 grit diamond will sharpen just fine.  Just takes longer than a file.

If you want to push that thought a 400 grit will sharpen as well (see electric edge sharpeners that use 400 as their medium stone which still cuts).  600 and above polish only.

post #29 of 43

This is a very good thread, IMO.  It touches on things I have been experiencing over the past few years. I use the pretty std. technique of progressively finer diamond stones to sharpen my side edges. Only deburr the bottom edges as needed. Occasionally I file the side edges before using the stones. I tend to use the file when the edges look banged up from some "off piste" activity. I deburr first, then use the file.

 

I have found there is dull, then there is sharp, and then there is razor sharp. Lately I haven't been getting to the razor sharp level on my skis with just the stones. I suppose I should be using the file more often, which maybe the main reason. When I use it I always seem to get back to razor sharp. When I don't use it, sometimes I get back to razor sharp and sometimes not. I do pay attention to my sidewalls and do the necessary planing with two different tools.

 

I can easily feel the difference on boiler plate surfaces and I can also feel the edges dulling over the course of the day when on boiler plate. I assume this is pretty normal for most, and this thread somewhat confirms this.

 

So why not razor sharp every time with the stones?

 

1.  It maybe time to replace my stones, they are probably 3-4 seasons old. I guess I have been thinking they are diamond and will never wear out? Somehow I think this is "too good to be true" thinking.

 

2. If the edges get banged up enough, the stones won't take off enough material to get back to razor sharp (I use 200,400,600 grits). Even with the 200 grit the stone stops cutting after so many passes. It does the noisey, then quiet, then slick progression described in a reply above. When it gets slick, it might mean it is time to clean the stone and the edges, and then repeat the process. This would make sense as the stone will get caked with the grey residue. I use Artech's cutting fluid on the stones every time. 

 

3. I might need to plane my sidewalls more often, but I think I do it often enough. I used the magic marker trick and took all the marker off the side wall with my stones.  BTW, that will leave a very black residue behind (it took me a minute to figure out where the "black" gunk was coming from).  After doing this I skied the skis and did not get "razor sharp" edges.

 

4.  Finally, it might be the hardness of the boiler plate surface. As the temp varies, the ice gets harder or softer. I skied in some -10F temps a couple of weeks ago and after sharpening a pair of skis with stones, did not have really good bite on some decent snow surface. The trail was steep and pretty well covered with hard powder, definitely not boilerplate, and I had to slow down to get my edges to bite in. My ski buddy on a pair of Stockli SC's was having no trouble getting an edge and I was sliding a bit on my MX78's. 

post #30 of 43
For what it's worth, I replace my 200 and 400 grit diamond stones every season. These are the higher priced WC ones as well; not the economy.
However we are a ski racing family so I'm sure I'm tuning much more than most. A quiver of 12+ skis (half of which are race skis) lends itself to this.
Our race skis get tuned almost every time they hit the snow.

As for "razor" sharp, I find rock hits to our free skis limit how sharp they can get (base hits mess with the actual edge geometry) compared to our race skis which are pristine and easily brought back to razor sharp status.
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