Sharpening Stainless Steel blades / sharpening woes

[Christy]

I'm starting a separate thread as I don't want to hijack another one. I saw a comment that not all skate sharpeners (the tool, not the person) can sharpen stainless blades. I know that Matrix blades need a special jig because of the chassis, but had always assumed that all skate sharpeners could sharpen both carbon and stainless blades.

The reason I ask is that I have Matrix stainless blades and have recently changed sharpeners, purely for geographical reasons. My old sharpener did a great job and I never had a problem. My new sharpener doesn't have the jig but can sharpen Matrix blades so I specified the ROH and provided a pair of blades recently sharpened by the good sharpener, however after 4 attempts there's been one sharpening that was OKish and I could skate with. All of the other sharpenings have resulted in me sticking to the ice, not being able to get any edges, and all sorts of other issues that have meant wasted ice sessions. Other people use that sharpener, and those with stainless blades have commented that they need one or two sessions after a sharpening to "break the blades in," which is not something I ever had to do with my old sharpener.

The new sharpener tells me he is doing the correct ROH so I am trying to work out the problem and how we can fix it. Obviously every skate sharpening machine is different, the diamond is different, the pressure applied is different, the number of passes, etc. but I am now wondering if it could be the fact the blades are stainless that is causing the problem? Any thoughts or advice please?

[Bill_S]

The first thing that I'd do is to check to see if the edges are level. Uneven edges may cause similar issues. Use a stick of wood and press it against the blade. Sight down the length of the blade to see if the stick is level across the edges.

You DON'T want to see something like this...



My Wissota sharpener provides a choice of two grinding wheels - one meant specifically for stainless, especially stainless hockey runners (https://wissota.com/product/911-skate-sharpener-80-grit-pink-grinding-wheel-stone),

...and another specifically for carbon steel blades - (https://wissota.com/product/blue-wheel).

Because I skate on carbon steel blades, I purchased the Wissota "blue" wheel designed for them. However, I have sharpened stainless blades using that wheel. They have all been children's skates with low-level blades FWIW. It takes longer to sharpen stainless because it cuts slower, and I need to dress the grinding wheel more frequently to keep it from becoming fouled. I can get a smooth finish on them if I use Wissota's Skate Sharpening Wax on the blade for the last pass or two, otherwise the surface is slightly rougher than carbon steel. However, I don't know if that difference is enough to produce what you describe.

To have something to compare, here's a photo of a carbon steel blade that I sharpened, for practice, on an ancient rusty pair of skates...



This is typical of what I get on carbon steel with the 100 grit wheel. I would suspect that the 80 grit (Wissota pink wheel) would not produce a surface as smooth because it is coarser, but I would still expect it to be fine on the ice.

Check for level edges first before exploring different grinding wheels.

[tstop4me]

I'm starting a separate thread as I don't want to hijack another one. I saw a comment that not all skate sharpeners (the tool, not the person) can sharpen stainless blades. I know that Matrix blades need a special jig because of the chassis, but had always assumed that all skate sharpeners could sharpen both carbon and stainless blades.

The reason I ask is that I have Matrix stainless blades and have recently changed sharpeners, purely for geographical reasons. My old sharpener did a great job and I never had a problem. My new sharpener doesn't have the jig but can sharpen Matrix blades so I specified the ROH and provided a pair of blades recently sharpened by the good sharpener, however after 4 attempts there's been one sharpening that was OKish and I could skate with. All of the other sharpenings have resulted in me sticking to the ice, not being able to get any edges, and all sorts of other issues that have meant wasted ice sessions. Other people use that sharpener, and those with stainless blades have commented that they need one or two sessions after a sharpening to "break the blades in," which is not something I ever had to do with my old sharpener.

The new sharpener tells me he is doing the correct ROH so I am trying to work out the problem and how we can fix it. Obviously every skate sharpening machine is different, the diamond is different, the pressure applied is different, the number of passes, etc. but I am now wondering if it could be the fact the blades are stainless that is causing the problem? Any thoughts or advice please?

<<Emphasis added.>> Here is another difference between stainless steel and plain carbon steel blades.  During grinding, burrs are formed along the edges.  The tech typically removes the burrs with a whetstone.  But the burrs on stainless steel tend to be more pronounced and persistent than on plain carbon steel.  So the deburring needs to be done more meticulously.  The fact that other skaters with stainless steel blades are OK after one or more break-in sessions points towards this problem.  If you don't know how to feel for burrs (Be careful! You can get nasty cuts on your finger tips, if you do it wrong.), ask an experienced skater or coach to show you how to feel for them, and, if present, how to remove them.

[tstop4me]

This is typical of what I get on carbon steel with the 100 grit wheel. I would suspect that the 80 grit (Wissota pink wheel) would not produce a surface as smooth because it is somewhat coarser, but I would still expect it to be fine on the ice.

I looked at the Wissota site, and they didn't specify the composition of the wheels.  On other brands, the wheels vary in composition as well as grit size:  typically (harder) silicon carbide for faster removal and (softer) aluminum oxide for a better finish. 

[Christy]

<<Emphasis added.>> Here is another difference between stainless steel and plain carbon steel blades.  During grinding, burrs are formed along the edges.  The tech typically removes the burrs with a whetstone.  But the burrs on stainless steel tend to be more pronounced and persistent than on plain carbon steel.  So the deburring needs to be done more meticulously.  The fact that other skaters with stainless steel blades are OK after one or more break-in sessions points towards this problem.  If you don't know how to feel for burrs (Be careful! You can get nasty cuts on your finger tips, if you do it wrong.), ask an experienced skater or coach to show you how to feel for them, and, if present, how to remove them.

I know the original sharpener definitely used a whetstone, as I watched him, but the new sharpener doesn't allow people to watch, however I did ask if he did that and he told me that he does.
I also asked how many passes he does on the wheel as the original sharpener did around 3, checked the blade, then another 2 or 3. The new sharpener seemed to think that was a low number and said he does about 10. Not sure if that makes a difference.

[tstop4me]

I know the original sharpener definitely used a whetstone, as I watched him, but the new sharpener doesn't allow people to watch, however I did ask if he did that and he told me that he does.
I also asked how many passes he does on the wheel as the original sharpener did around 3, checked the blade, then another 2 or 3. The new sharpener seemed to think that was a low number and said he does about 10. Not sure if that makes a difference.

There's still the issue of how well he uses the whetstone.  At one time, a very good sharpener went MIA, and several of my friends went to a new guy.  They were having all sorts of problems.  I checked their edges, and the deburring was done sloppily (and these were plain carbon steel).  I carry a whetstone [and a steel (I'm probably the only person who does)] in my kit bag.  I fixed the burrs, and they were really happy.  So you still need to check ... as well as the levelness of the edges, as Bill suggested.

[Christy]

There's still the issue of how well he uses the whetstone.  At one time, a very good sharpener went MIA, and several of my friends went to a new guy.  They were having all sorts of problems.  I checked their edges, and the deburring was done sloppily (and these were plain carbon steel).  I carry a whetstone [and a steel (I'm probably the only person who does)] in my kit bag.  I fixed the burrs, and they were really happy.  So you still need to check ... as well as the levelness of the edges, as Bill suggested.

Will definitely check the levelness and work out how to check for burrs. I'm not sure the coaches know as they just suggested the skates might be too sharp. Actually that's what the new sharpener said too. He said maybe change ROH to 1/2 and that would reduce sharpness, but I think the burrs possibility sounds more sensible as I tried 1/2 once and didn't like it, and I've always been happy with 7/16ths. I'm also a bit confused about how "too sharp" would make my blades stick to the ice 

[tstop4me]

Will definitely check the levelness and work out how to check for burrs. I'm not sure the coaches know as they just suggested the skates might be too sharp. Actually that's what the new sharpener said too. He said maybe change ROH to 1/2 and that would reduce sharpness, but I think the burrs possibility sounds more sensible as I tried 1/2 once and didn't like it, and I've always been happy with 7/16ths. I'm also a bit confused about how "too sharp" would make my blades stick to the ice 

If you can't find someone who knows how to check for burrs, let me know, and I'll make a sketch (rather convoluted using words only).

[Christy]

If you can't find someone who knows how to check for burrs, let me know, and I'll make a sketch (rather convoluted using words only).

Thank you so much for the offer    I'll ask around and let you know if I can find the info.

[Query]

One of the signs of a good sharpener is that the results are CONSISTENT. I'm not convinced by your description that he qualifies. I'm not sure that the wrong wheel would produce the inconsistent results you describe. Though if he uses a really coarse grain wheel, so he can sharpen blades faster, that might lead to somewhat inconsistent results, as well as very dull edges.

I wonder if, without the right jig, he is trying to level and/or center the blade on the wheel by hand. A really good tech can do that, using hand or power tools, but you need better hand-eye coordination than I personally possess.

If the sharpener is GOOD, and doesn't remove much metal / sharpening, a blade will last about 30 sharpenings, more or less. (Assume a good sharpener using power tools removes .003 inches of steel. Assume the relationship of your toe pick to the rest of your blade is messed up after .1 inches are removed.) So -- drop 3 sharpenings off the lifetime, and see how much the bad attempts cost you in terms of replacing blades - you are paying for more than lost ice time. E.g., if your blades cost $300-$500 per pair, each sharpening costs you at least $10-$16.67 more per pair than you think, maybe several times that. Add in lost ice time, wasted lessons, and he is costing you a lot. If you actually drive to his shop, that costs you more too.

If he isn't very good, he is probably removing more metal, maybe several times as much or more, and you may be paying even more for his sharpenings, indirectly. If there is another nearby tech within a few hours drive, it is likely worth it. Dubious techs also frequently modify the rocker profile (the longitudinal edge curvatures) in unpredictable ways, leaving you with a blade that can be very difficult to skate on. For example, new blades have one or more transition points up front, near the ball of your foot, between different rocker curvatures. You typically balance on or near that point, especially when turning or spinning. But if the tech smooths out the transition, or moves it, you can't feel where it is anymore, and you may rock around different parts of the blade. A really, really bad tech may remove part of your toe pick, and if he does that badly enough, you may as well throw away the blade.

Amazingly, some skaters van learn to skate on slightly uneven blade edges. But if the tilt goes back and forth along the blade, that gets really hard to correct for.

Another possibility: are either of your blades warped? E.g., if you put a straight edge along the side of the blade, can you see a gap anywhere? A second rate skate tech using a power sharpener, especially one without the proper blade holder, will produces edges that tilt one way at the ends, and another in the middle, or some other such uneven pattern.

Very sharp blades are BTW very easy to have misaligned, in terms of the fact that the edges might not point straight down. In particular, sometimes the edges are pushed off to the sides by sharpening - forming a "lip" or "burr".

If you want to feel the edges, to see how they point, touch them very lightly. I do not recommend drawing your finger ALONG the edge, as it is quite easy to cut yourself that way. I draw my finger ACROSS the edge, very, very lightly. If you do cut yourself (I don't, anymore), wash the cut clean, and bandage - you don't want an infection.

You can point the edges correctly, or deburr them (deburring means deliberately making them less sharp, but the ultrasharp pointed foil edges I prefer are more fragile), using a number of techniques. I take a small very fine grain flat sharpening stone, and brush the edge from the side upwards. In fact, half the time or more, that will work just as well as re-sharpening the edges, because a lot of the time non-sharp edges have just been bent. The technique is a little harder for edges that are bent inwards, but if you are careful, you can do it.

The usual technique is not to slide the stone along the sides - which scratches them up, and possibly therefore slows down the blades - but to bend them very slightly inwards.

There are a lot of Youtube videos demonstrating this type of thing.

tsop4me says he prefers using a "steel" to straighten edges. I haven't tried that. I like the fine flat stone partly because it also polishes the edge to make the edge more clean, but in theory, a steel might mean you would need to fully sharpen even less often.

Have you asked other skaters what they are doing about this bad tech? I assume they are having problems too. Maybe they have found someone they like, and you can carpool, or alternate who takes a group of skates with them to the distant tech.

I personally love sharpening myself using good purpose-built hand tools, like the Pro-Filer, but I admit it takes time to learn to DIY. It costs about $80 and is only available for 3/8" and 1/2", which is high - but compared to the costs I just cited, it isn't so bad. I try to remove no more than about .001 inches / sharpening - but if your dubious skate tech has made the edges uneven, or made them very dull, you will need to remove more to correct things the first time. If you do it right, you can substantially increase the lifetime of your blades relative to sharpening with power tools, especially if your tech is incompetent - but of course, you can do it wrong. E.g., it is really important you trace or otherwise record the original rocker profile, so you don't lose it. I also like to cover the toe picks with tape first, so I can't destroy them.

Buying your own power sharpening tool, like Bill did, is a pretty expensive route, if you are only doing your own blades. And that has an even bigger learning curve, because metal comes off so fast. Also, it won't fit in your skate bag. I personally haven't done it.

[Christy]

Thank you for the info. It gives me a lot to consider.

Most people use this sharpener, as there aren't many options, however very few have Matrix blades. In fact the only person I know who has Matrix blades did say they had some problems after a sharpening, but I think they have adapted to the way the blades have been sharpened. I can't visit my original sharpener because of Covid, but plan to return to them as soon as I can, so this is a (hopefully) temporary problem. I totally understand what you are saying about shortening the life of the blades and I don't expect them to last beyond the sharpenings with this new sharpener! Fortunately I managed to get them for a good price, and the sharpener said they'd checked them and they weren't warped. (I do trust them with this as they are very detail oriented).

To be fair this new sharpener is very willing to work with me to try to get a sharpening that works, but I think their experience and knowledge of Matrix blades is very limited and the lack of the correct equipment is definitely causing problems.

As I say I provided a pair of blades sharpened by my original sharpener as a guide and told them I wanted an ROH of 7/16ths. After the first sharpening I explained the problems I was having, and both the sharpener and my coach said maybe they were just too sharp. When I asked if they finished the blades with a stone they said they did but I got the impression it was just a cursory glance. I will ask specifically if they check for burrs and remove them, but I think I may get a blank look.

One thing I am struggling with is that both new sharpener and coach I ask keep saying the problem is probably the blades being too sharp (but I'm sticking to the ice!), then the sharpener says they will change ROH from 7/16th to 1/2 so they won't be as sharp, but I didn't think the ROH dictated the sharpness. I get the impression the sharpener is making a lot more passes on the wheel, and I was thinking that would make them sharper, and from the info I've learned today I'm wondering if more passes on the wheel would also cause more burrs? Am I totally wrong?

I'm thinking I should say 7/16ths (because that's always worked in the past), only 4-6 passes on the wheel, and check really well for burrs and stone them out (which pretty much describes the process of my original sharpener, which worked)

[tstop4me]

If you can't find someone who knows how to check for burrs, let me know, and I'll make a sketch (rather convoluted using words only).

Thank you so much for the offer    I'll ask around and let you know if I can find the info.

I had time to kill; here you go.  Let me know if you need clarification.  [Note:  This is the method I use.  Other people use different methods.]

CHECKING FOR BURRS ON A FIGURE SKATE BLADE

Click figure below to enlarge.  I've used a Paramount blade for illustration, but the construction is similar to a Matrix blade (chassis plus runner). 

(1) Place one skate (boot plus blade) on a table or on your lap.  Blade is oriented as shown in Fig. 1A (boot not shown): blade is horizontal, side of runner facing up, edge pointing away from you.  Hold the skate down firmly with one hand.

(2) Refer to Fig. 1A.  You should test the entire length of the blade (from drag pick to tail) for burrs.  The vertical red arrows indicate the approximate positions along the blade at which you should test; pay extra attention to the spin rocker.  I test about every 3/8" along the spin rocker, about every 1" along the main rocker, and at the tail.  Exact spacings aren't critical; i.e., you don't need to use a ruler.

(3) Refer to Fig. 1B.  At each test position, you use a sliding fingernail test to check for the presence of a burr.  I use my index finger (of my free hand; i.e., the hand not holding down the skate).  Place the tip of your fingernail such that it lightly touches the side of the runner.  [Caution:  Use the tip of your fingernail.  Do not use the fleshy tip of your finger (under some scenarios, you can get a nasty cut if you do.] Starting position is about 1/8" below the edge (not critical).  Slowly slide the tip along the side of the runner in the direction shown (perpendicular to the edge); the tip should maintain contact with the side of the runner as you slide the tip.  Slide the tip towards the edge.  Continue sliding until the tip just passes the edge. 

(4) If there is no burr, you won't feel anything.  If there's a minor burr, you will feel a slight bump near the edge.  If there's a major burr, your tip will snag.

(5) Repeat the sliding fingernail test at each position indicated in Fig. 1A.

(6) Flip the skate left-to-right.  Repeat the tests on the other side of the blade; i.e., you check for burrs along the inside edge and along the outside edge of the blade.

(7) Repeat the sequence with the other skate; i.e., you check for burrs along a total of four edges (inside edge of left skate, outside edge of left skate, inside edge of right skate, outside edge of right skate).

( 8 ) It's not as bad as it sounds.  The first time, proceed slowly and deliberately to avoid cutting yourself.  With practice, you can do everything in about a min or two. 

[tstop4me]

One thing I am struggling with is that both new sharpener and coach I ask keep saying the problem is probably the blades being too sharp (but I'm sticking to the ice!), then the sharpener says they will change ROH from 7/16th to 1/2 so they won't be as sharp, but I didn't think the ROH dictated the sharpness. I get the impression the sharpener is making a lot more passes on the wheel, and I was thinking that would make them sharper, and from the info I've learned today I'm wondering if more passes on the wheel would also cause more burrs? Am I totally wrong?

I'm thinking I should say 7/16ths (because that's always worked in the past), only 4-6 passes on the wheel, and check really well for burrs and stone them out (which pretty much describes the process of my original sharpener, which worked)

* Depends on how you define sharpness.  If you approximate each edge of the blade as a V-shaped knife edge, then one characterization of sharpness is the included angle of the V (also known as wedge angle or knife angle).  With careful qualifications (which I won't get into), the smaller the included angle, the sharper the edge. 

* A skate blade is ground with a hollow to provide two distinct edges, an inside edge and an outside edge.  The included angle of each edge is indeed varied by changing the radius of hollow (ROH).  A smaller ROH yields a smaller included angle; hence, a sharper edge.  I posted a detailed mathematical analysis in 2015:  http://skatingforums.com/index.php?topic=7547.msg90425#msg90425.  Note that the change in included angle with ROH is slight, but many skaters can feel the difference under actual skating conditions between, e.g., a 7/16" and a 1/2" ROH or a 3/8" and a 7/16" ROH.  The ease of glide and the degree of edge control depends on a number of factors, including ice temperature, weight of skater, and (perhaps most importantly) skill of skater.  Under the qualifier "all other things being equal", a sharper edge will bite more into the ice, resulting in reduced glide (but the blade shouldn't stick under the typical range of ROH).

* If the grinding wheel is properly centered with respect to the blade, the inside and outside edges will be level, and the included angles of the inside and outside edges will be the same; i.e., they will be equally sharp.  If the grinding wheel is not properly centered with respect to the blade, the inside and outside edges will not be level, and the included angles of the inside and outside edges will not be the same; i.e., one edge will be sharper than the other.  In that case, you should notice a substantial difference in glide and edge control depending on whether you are on an inside or outside edge.

* In most (not all), commercial sharpening machines, the ROH of the grinding wheel is set by dressing the wheel with a diamond-tipped dresser.  The position of the dresser can be varied to vary the ROH.  There are typically calibration marks on the dresser assembly that indicate the values of the ROH.  If the dresser assembly is out of whack, the ROH of the wheel can differ from the indicated value.  That is, even if the tech sets the ROH to 7/16", the actual ROH could be, e.g., 3/8" (leading to sharper edges than intended) or 1/2" (leading to duller edges than intended).  The only way to know for sure is to use special gauges to measure the final ROH on the blade itself.  These gauges do require some practice and skill to use properly.  Most techs I've come across do not measure actual ROH on the blade.  If you want to play Sherlock Holmes, you'll need to buy your own gauges and learn how to use them properly [if you go this route, make sure the gauge is compatible with your blade].

* You can't simply go by the number of passes.  The amount removed varies with the grit and composition of the wheel, rotational speed and diameter of the wheel, the particular steel of the blade, and the particular technique used by the tech (e.g., pressure and feed rate).  Depending on all these variables, 3 passes in one scenario could remove more material than 10 passes in another scenario.

* Sorry, but life is complicated, if you simply want to skate.  If you have a good tech with good equipment, you don't need to fret about all these details.  But if you don't, .....

[Christy]

Oh wow, thank you so much for the information. I'm going to read through it in more detail and check my blades over to see what I can find.

[Query]

AFAICT, 7/16" is the most common figure skating ROH, in the area I live. It is not extreme.

Changing ROH potentially wastes a lot of metal, particularly when you go to a larger ROH. Don't do it more often than you need to.

ROH has a big effect on the sharpness that you feel, but isn't everything. A lot of sharpness depends on how much the edge is "rounded off", as well as whether there is a planer "foil edge" that extends past the included angle created between the hollow and the sides of the blade, and in the latter case, how long that foil edge is. Finally, if your edges are not level, especially if they vary in relative length along the blade, that too can make a blade act less sharp, because your edge will sometimes be misaligned relative to the ice and the direction you push against it.

Have you ever sharpened a pocket knife or kitchen knife with a flat grinding "stone"? The most common technique I've seen is to pull (draw) the blade  (blunt side first) against the flat stone, so that the pressure from the stone gradually pulls out the metal, polishes and lengthens the edge. The angle of the blade to the stone sets the included angle, which is one form of sharpness, which is what ROH sets. But, because the metal is pulled thin, there is a "foil edge", resembling a very thin sheet of metal, attached to the included angle, that adds a lot of extra sharpness.

The pressure from the stone also pushes that edge to one side and another. That's why you draw alternately on opposite sides of the blade - and why you gradually decrease the pressure as you do so, so the foil edge ends up centered.

(There is, BTW, an alternate technique, where instead of pulling out the length of the foil, you push the blade, sharp side first, against the stone, that I think doesn't produce a foil edge.)

Powered skate sharpening machines work differently, but there are similarities.

Most are longitudinal grinders, which turn along the blade. On all the machines I have seen except one very low end automated consumer market tool, you use a diamond dresser to shape the wheel, across its thickness, to the desired ROH. You then grind the wheel against the blade. You slide the blade along the tool to get most of the blade.

That grind creates the overall hollow shape and ROH, which in turn creates the inside and outside included edge angles between the hollow and the sides of the blade.

Depending on a number of factors, like the speed, composition and coarseness of the wheel, the speed the tech works at, perhaps the composition, hardness and tempering of the blade, and whether or not the tech uses a lubricant, the stone sometimes pushes rough little lips or burrs out sideways from the blade.

Based on an informal microscope study, a relatively coarse wheel, with no lubricant, does NOT produce a foil, or lip or burr, on the machine I tested that on. But a fine grain wheel does, perhaps especially if you lubricate the metal as you grind.

Likewise, with the finer grain Pro-Filer hand tool, I do get one, especially if I lubricate.

What you then do with that foil, lip or burr tremendously affects the effective sharpness. "Deburring" usually means removing it. It usually also rounds off the edge a bit, and you get a relatively dull edge. The advantage is that there is less difference between a newly sharpened blade and one you have used for a while, so you don't need to adapt much between new and older blade edges, within limits.

The other method is to polish the foil, lip or burr into a true foil, so it is very flat and thin, and to push it around so it extends vertically down into the ice.

A foil is overwhelmingly sharper than the edge from the included angle. So, if it is properly pointed in the right direction, it is much more effective in preventing skids. If it were too long, it would sink too deep into the ice, and slow you down. But the idea is to make it fairly short, so the included angle from the hollow grind stops it from sinking too deep.

In the speed skating world, few people deburr. (Note they also use a flat stone to create a flat bottom instead of a hollow, so they only have a 90 degree angle at the included edges, which isn't very sharp - foils help.) In fact, they tend to create fairly long foils, which gives them a lot of bite at the start of a race heat. By the end of a race heat, they have mostly worn down the foil.

Instead of needing ultra-sharp blades, you CAN learn to point your skates and edges very precisely, so when you push down on a blade, the blade is angled precisely at right angles to the direction of push. With that technique, you can get away with edges that are not very sharp. (You can also, like many hockey players, push very hard into the ice.) I sometimes deliberately let my blades go dull, so I can get that blade alignment trick back, and am less dependent on sharp blades.

But on rough ice, or on ice that varies in hardness with temperature, ultra-sharp foil edges cut through the surface junk, and let me skate smoothly and fairly fast despite the rough surface. The way I skate doesn't have to depend much on how smooth the ice is, or its temperature.

But with foil edge, if I walk on the edges off-ice - even on rubber mats - without blade guards, that pushes the foil back out to the sides, which effectively means there is no edge. It's a trade-off. Even a very hard stop might push it over.

I like foil edges partly because it comes from reshaping the blade. I don't need to remove as much metal per sharpening. But it is more fragile, and requires more frequent sharpening.

You need to figure out what you like, for the rinks and conditions you skate on. If your ice conditions are fairly consistently good, maybe you don't need super-sharp blades.

If you sharpen yourself, you can play to find what you like. Skaters vary substantially in what they like, and skate techs vary substantially on what they try to produce - especially if they aren't specifically asked to produce a particular edge type. What is more, very few skate techs are capable of producing very consistent results using powered sharpening machines. I can get more consistent results with hand tools.

Techs also vary a lot in what they do near or on the toe pick. In principle, the part of the "spin rocker" (see tstop4me's diagram) closest to the toe pick doesn't touch the ice, because of the angles involved, and doesn't need to be sharpened. Sid Broadbent calls it the "NSZ=non skating zone" or something along those lines. Likewise, unless you do a tremendous number of jumps, the toe pick will stay fairly sharp. But if you push hard, do a jump landing, they get used, and you can skid there too. AFAICT, it is very hard to sharpen the NSZ or toe pick with powered sharpening tools, but I have done it with hand tools.

The Matrix blades I have (an older model, which had replaceable runners) were factory sharpened very sharp, including the NSZ toe pick - much sharper everywhere than the MK and Wilson blades I used to use, and sharper than most skate techs do. I don't know if that is still true of modern Matrix blades.

BTW, some skate techs get a little extra life out of blades by trimming the toe picks shorter when so much metal has been removed from the rest of the blade that the toe pick gets in the way. Most don't try, and you can only go so far before the working part of the toe pick gets too far forward of the rest of your foot. That's probably not a factor for you yet, but it is one more excuse for learning to sharpen yourself.

[Christy]

Thank you for the info. Still processing a lot of it, but yes, for my original sharpener I got the impression 7/16ths was the most popular ROH, however not sure that's the case with the new sharpener.

I'd say the ice does change from summer to winter, but it's fairly consistent across a season. Am I correct in thinking that sharpness is not what would cause me to stick to the ice, not get edges, etc. but burrs or uneven blades would cause problems?

[MCsAngel2]

I mean, it's true that a deeper grind (7/16 is deeper than 1/2) will give your blades more bite (which might or might not also be described as sticking) because there's more edge to be pushed into the ice. But that's an issue you'd notice skating on the different grinds, you shouldn't see a difference if it's always sharpened to 7/16.

[Loops]

Something that happened to me.....I skate on a 3/8, and one of our sharpeners here at the rink gave me something so deep it was off my gauge.  It was scary to skate on, although I don't recall it being sticky.  But could this new guy be giving you a "7/16ths" that is, you know, maybe deeper than your normal guys 7/16ths? (and no, I don't let him sharpen my skates anymore)

I don't know how many take the time to measure and double check their work......

[Query]

You can guess ROH with coins.

A 3/8" ROH will exactly fit a a U.S. penny.

A 7/16" ROH is between a U.S. nickel and quarter.

A 1/2" ROH is slightly smaller than a U.S. dollar coin. (Editted - I orginally said bigger)

I based that on https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications

BTW diameter=2*radius.

A "radius gauge" set, also called "radius gage", "fillet gauge" or "fillet gage", with inch units in the right range, is fairly cheap online, and gives you more precision. The cheapest are in metric units, but you could convert.

With a little work, one of us could draw circles of appropriate radius on a PDF, with inch scales in each dimension that you could verify were scaled right when you print it. But it is harder to visually match than to physically fit a coin or gauge against the hollow.

If your local hardware store doesn't have a gauge set, maybe they have 7/16" dowel rod or pipe that you could buy in a short length? (Dowels aren't always perfectly round, or exactly cut, but are close enough if you aren't too picky.)

It is possible that a blade that isn't new cut, will have a little flatter hollow than the desired ROH nearest the sides. Try to fit against the center.

Perhaps one of the engineers here could work out a better way to make a cheap home made ROH tool?

But the original poster complained of inconsistent results. If the sharpener (skate tech) used a badly calibrated tool, that isn't what they would get.

[LunarSkater]

Just adding two cents in, about the sharpening process. Does your tech redress the wheel between skates and make sure that the blade is level to the wheel or does he sharpen as a pair? My tech always treats each blade individually and it prevents a lot of problems. People wear edges differently on each skate and they can't be treated as a unit.

[tstop4me]

Just adding two cents in, about the sharpening process. Does your tech redress the wheel between skates and make sure that the blade is level to the wheel or does he sharpen as a pair? My tech always treats each blade individually and it prevents a lot of problems. People wear edges differently on each skate and they can't be treated as a unit.

Could you clarify what you mean?  With standard sharpening equipment, figure skate blades necessarily need to be sharpened individually.  The only duplex sharpening units I've seen are manual units for speed skate blades (since they have no hollow and are ground flat).

[tstop4me]

Perhaps one of the engineers here could work out a better way to make a cheap home made ROH tool?

You can buy a set of el-cheapo radius gauges in the $20 - $25 range (typically 1/2" max; you'll need extras for larger sizes).  These are not hardened and precision ground like the high-grade sets used by machinists in a good shop, but adequate for infrequent use as a blade checker.  In my area, that's the cost of one sharpening.

[tstop4me]

delete

[LunarSkater]

Could you clarify what you mean?  With standard sharpening equipment, figure skate blades necessarily need to be sharpened individually.  The only duplex sharpening units I've seen are manual units for speed skate blades (since they have no hollow and are ground flat).

Absolutely! I wrote it waaay too early in the morning. My tech (who's teaching me to sharpen) and my own personal experience have taught me that bad skate techs treat a pair of skates as a single unit. They'll set up the wheel for one blade, sharpen it, and then sharpen the other blade without adjusting anything. It often ends up with one skate that has uneven edges and the other skate perfectly fine.

[tstop4me]

Absolutely! I wrote it waaay too early in the morning. My tech (who's teaching me to sharpen) and my own personal experience have taught me that bad skate techs treat a pair of skates as a single unit. They'll set up the wheel for one blade, sharpen it, and then sharpen the other blade without adjusting anything. It often ends up with one skate that has uneven edges and the other skate perfectly fine.

Thanks.  That makes sense.