Sharpening spontaneously gone bad?

[jjstuart79]

Hi! I just started sharpening my daugthers figure skates. There's been some bad sharpenings, but it's getting better. The last sharpening I did she skated on them twice for 5 hours total and said they were just fine. But the very next time she skated, she complained that the skates gripped the ice WAY too much and when she tried to get on an edge, they were sliding. From what I observed, the ice crunched noticebly more than normal on power pulls, but when she would get into a spin or do something like a twizzle, the skate would slide, then catch and make her fall or trip. When I inspected the blade, there wasn't any noticable damage to them, they felt sharp when I ran my finger across the blade and the edges were still even. Since I'm new to sharpening I'm concerned I did something wrong, but I can't figure out how they could have spontaneously gone bad. She had an important practice the next day, so I had someone else resharpen them. I appreciate any input, I'm really confused as to what could have happened. I'm also curious how the skates could grip the ice too much, but also slide when on an edge?

More information on the sharpening
I'm using a Wissota sharpener with an 80 grit wheel. The blades are MK professional sharpened to a 7/16 hollow and I used a leather strop to clean the edges (deburr?) after sharpening.

[tstop4me]

More information on the sharpening
I'm using a Wissota sharpener with an 80 grit wheel. The blades are MK professional sharpened to a 7/16 hollow and I used a leather strop to clean the edges (deburr?) after sharpening.

Are you using the leather strop plain or charged with abrasive?  If plain, it's likely not removing the burrs adequately.  Did you check for remnant burrs?  They can cause erratic behavior as they deform.

[AlbaNY]

I find it odd that she felt a slide then too much grip.  For me it is one or the other only. 
It also sounds very strange to me that she was okay for several hours before feeling not okay.  I just had an off day, for some reason, that felt like I couldn't do basic back 3s and such that I might have blamed on a sharpening if I had any chance to.  Perhaps it was just a really weird day like that?

I'm new to sharpening, so I don't want to try and say much of anything about that except that I like to use a block of wood to gently dull the edges after sharpening.  I use an Arkansas stone in between but forget now which grade.

I'm following this to see if I can learn from her problem.

[jjstuart79]

Are you using the leather strop plain or charged with abrasive?  If plain, it's likely not removing the burrs adequately.  Did you check for remnant burrs?  They can cause erratic behavior as they deform.

I'm using it plain. I did not feel remnant burrs, but I am pretty new to this so can't count it out. I also have the Wissota honing stone, but I'm always afraid I'll dull the blade when using it. But maybe I'm worrying too much about that?

Honing stone
https://wissota.com/product/skate-sharpening-hand-hone/

[jjstuart79]

I find it odd that she felt a slide then too much grip.  For me it is one or the other only. 
It also sounds very strange to me that she was okay for several hours before feeling not okay.  I just had an off day, for some reason, that felt like I couldn't do basic back 3s and such that I might have blamed on a sharpening if I had any chance to.  Perhaps it was just a really weird day like that?

It's very confusing to me also and I can't count out just having a bad day. Seeing her skate, things were definitely off though.

[Bill_S]

Slipping AND gripping?

When blades edges are not level, one edge will be sharper than the other. That means skids in one direction, and grip in the other.

The first thing that I'd do is check to see if her edges are level. For a quick assessment, lay a straight ruler or piece of wood across the blade and sight down the length of the blade. The straight edge should be perpendicular to the blade. See the examples below...

Yes


NO!


It's easy to do a quick check for this problem without expensive, and more sensitive, edge checking tools.

[jjstuart79]

Slipping AND gripping?

When blades edges are not level, one edge will be sharper than the other. That means skids in one direction, and grip in the other.

I did check the edges before resharpening and they were pretty spot on except the last maybe inch on the back right skate. The inside edge was roughed a bit and was off a line or two. I have the sparx edge checker. I didn't think much of it since it was so far back.
I did manually check the sharpness of each edge, but it was just running my nail across them. I'm becoming more suspect of using the leather strop to clean the edges after sharpening. Could the sharpening be creating a ridge that over time makes one edge a bit duller than the other? And if so, is there a honing stone or maybe a certain grit that is recommended?

thanks

[Bill_S]

Could the sharpening be creating a ridge that over time makes one edge a bit duller than the other? And if so, is there a honing stone or maybe a certain grit that is recommended?

thanks

It's been my experience with the Wissota (but using the softer blue wheel) that I don't get much edge burr to deal with after sharpening. I use the flat stone from an old Pro-Filer hand-sharpening kit to remove the burr with just a light pass or two. I don't know the grit, but it's fairly fine. A leather strop would be best if mounted on a stiff substrate, like this one - https://www.leevalley.com/en-us/shop/tools/sharpening/75254-leather-strop?item=33K9110 - to reduce accidental dulling sections of the edge.

It would be unlikely that a burr would cumulatively build up to a degree that affects skating after several sharpenings. They just don't build up like that.

[jjstuart79]

It's been my experience with the Wissota (but using the softer blue wheel) that I don't get much edge burr to deal with after sharpening. I use the flat stone from an old Pro-Filer hand-sharpening kit to remove the burr with just a light pass or two. I don't know the grit, but it's fairly fine. A leather strop would be best if mounted on a stiff substrate, like this one - https://www.leevalley.com/en-us/shop/tools/sharpening/75254-leather-strop?item=33K9110 - to reduce accidental dulling sections of the edge.

It would be unlikely that a burr would cumulatively build up to a degree that affects skating after several sharpenings. They just don't build up like that.

Thanks for the info. I might have to chalk this one up as a fluke.

[Query]

I use a 5000 grit flat stone, but that may be finer than you need, and was more expensive than coarser stones. I use it because I am trying to reshape the burr into a very thin (effectively extra sharp) "foil edge", which would be very grabby, as well as rather fragile, and is not what most skaters are used to. I guess 1000-2000 grit might be good enough for deburring, and for the deliberate slight edge dulling that most skaters find desirable. But the 100-300 grit stone you buy at a cheap store might make a mess of the edges. 5000 is on the border of what some people use for razor blades, which need to be much sharper than skates. And an uncoated leather strop is effectively even finer.

Did you check that the edges were perfectly vertical? Part of the purpose of the stone is to make sure they are. I'm not sure a leather strop would even be sufficient to reshape the edges to be vertical - remember that the edge angle of skates is much greater than that of razors, and of most cutting tools, so it is harder to bend.

If she stepped off ice without a skate guard, bending the edge, or if you didn't make the edges vertical, a non-vertical edge could cause a skid, because she is skating on the side of that edge, rather than the point. That is more likely to happen with very sharp edges. Which is part of why most skate techs do dull the edge a bit just after sharpening it.

I hope your daughter forgives your initial learning curve.

Did you remember to trace her blade, so you can retain the rocker profile? I think what I call the sweet spot - the transition between the main rocker curvature, and the spin rocker, which is ideally approximately under the ball of her foot - is the most important thing to retain. After a few sharpenings, you (or she) will wear it down, until it becomes harder to find. That is often considered the best place to turn and spin, so it is important she be able to still feel it.

[jjstuart79]

I use a 5000 grit flat stone, but that may be finer than you need, and was more expensive than coarser stones. I use it because I am trying to reshape the burr into a very thin (effectively extra sharp) "foil edge", which would be very grabby, as well as rather fragile, and is not what most skaters are used to. I guess 1000-2000 grit might be good enough for deburring, and for the deliberate slight edge dulling that most skaters find desirable. But the 100-300 grit stone you buy at a cheap store might make a mess of the edges. 5000 is on the border of what some people use for razor blades, which need to be much sharper than skates. And an uncoated leather strop is effectively even finer.

Thanks, I'll try and find a 1000-2000 grit stone.

Did you check that the edges were perfectly vertical? Part of the purpose of the stone is to make sure they are. I'm not sure a leather strop would even be sufficient to reshape the edges to be vertical - remember that the edge angle of skates is much greater than that of razors, and of most cutting tools, so it is harder to bend.

Would using an edge checker count as checking for vertical edges? If not, I'm unsure how to best do this.

I hope your daughter forgives your initial learning curve.

lol. Me too! There's been some frustration, but I think she sees the benefit in having me sharpen them.

Did you remember to trace her blade, so you can retain the rocker profile? I think what I call the sweet spot - the transition between the main rocker curvature, and the spin rocker, which is ideally approximately under the ball of her foot - is the most important thing to retain. After a few sharpenings, you (or she) will wear it down, until it becomes harder to find. That is often considered the best place to turn and spin, so it is important she be able to still feel it.

I actually do have a tracing. I got the idea from an old post on this forum and surprisingly the wear has been pretty even on both skates.

[Query]

Would using an edge checker count as checking for vertical edges? If not, I'm unsure how to best do this.

The shorter edge is effectively a little less sharp, and is also harder to reach. So it acts a bit like a non-vertical edge.

BTW, a burr, off to the side, also creates a sliding surface which lets the skater skid sideways.

Probably best to use a small square. I check for burrs off to the side, and to some extent, non-vertical edges, by gently sliding my finger across (not along - or you might cut yourself) the sides, edges, and hollow. I also sight along the blade and its edges. Everything should line up - a wavy edge is harder for the skater to follow. Nothing should protrude to the sides. You can also see whether your hollow (and ideally, sides) is mirror smooth (some people use oil or polishing fluid), and has no non-uniform defects.

Actually, some skate techs actually bend the edges slightly inwards. Perhaps they do so because that angle means the flat stone does not touch most of the sides of the blade, so it doesn't scratch them. Scratches creates extra friction, slowing down the desirable glide along the length of the blade. If you do that, I suggest you don't bend it inward more than a few degrees at most. (In theory, I think it would better to bend the edges slightly outwards, because you skate leaned over onto the edges, but that would be slightly harder to do in a uniform manner.)

Let me reword what I said about your daughter forgiving you for your sins. Many pro shops isolate the skate techs from their customers, and give the skate techs little feedback on the job they are doing, or motivation to improve. I think almost any craft person who wants to improve benefits from receiving feedback. Your DD is eagerly providing you the benefit of such feedback. This is a good thing!

BTW, I'm not an expert. I've just been sharpening my own blades (with hand tools, like Pro-Filer and the old Berghman skate sharpeners) for some time, and have tried to learn from my mistakes. I have not benefited from the helpful feedback of your DD, so you will soon be much better. All the best skaters at your rink will want you to sharpen their skates, and your daughter will take great pride in shaping you to be better.

"This is the way."