Resetting base bevels - best way to flatten skis

[Noodler]

I have a couple pairs of skis that are over-beveled and really pretty much "unskiable" for me. So I brought the skis into a new local shop that uses a Wintersteiger stone grinding machine. I discussed what I needed done and wrote the instructions on the work order (to ensure that they were ground all the way to totally flat edge to edge since I needed to reset the base bevels).

When I picked up the skis, I brought along my true bar to see if they had actually gotten them to fully flat edge to edge. I wasn't totally surprised when I found that the skis weren't flat from the very edge to the other edge. Yes, the bases were flat, but the edges barely got touched. So I pointed this out and discussed it with the tech. He gave me a sharpie marker and I coated the edges to hopefully see if the machine was hitting "all" of the edge. The tech ran the skis over the grinder for a few more passes, but unfortunately the lubrication water (plus whatever they add to it) erased the sharpie, so it was still hard to tell if he had actually gotten the job done.

I took the skis home, ran a sharpie down the edges and proceeded to reset the base bevels. I use the Toko WC guide that is the widest available (it spans the width of most skis, up to about 90mm). I like the Toko WC guide because you can't over-bevel with it. So as I suspected, the file was bare hitting any of the edges. They were still way over-beveled and I didn't have a fully flat ski.

I brought both sets of skis back to the shop since as I said, if I can't get this fixed they're basically useless to me. I discussed the situation with the tech again and he suggested putting them on the belt sander. I was reluctant to go that route since I don't like what the belt does to the base finish and my previous experience with using belts is that although they can hit the edges, you don't end up with the edges being totally flat. They end up with a very uneven and unintended base bevel.

So if you've stuck with me through this whole diatribe, what is the best method to achieve a consistent fully and perfectly flat base that's ready to have the base bevel set?

Paging @Doug Briggs.

 

[Doug Briggs]

I have learned recently and from this site that I can use the stone to zero out the base bevels. In the past I was advised not to let the edges hit the stone. I have done many race skis since and gotten absolute zero for the base bevel. Still bring them in @Noodler, I'll take care of it for you. I am very happy with the results I am getting now blanking skis. The Scout makes it almost trivial. My fear of gouging the stone and shortening its life has since disappeared.

Using a belt to try and flatten skis is useless. You'll never get less than one degree base bevel and the bases will only approximate flat.

 

[Noodler]

I have learned recently and from this site that I can use the stone to zero out the base bevels. In the past I was advised not to let the edges hit the stone. I have done many race skis since and gotten absolute zero for the base bevel. Still bring them in @Noodler, I'll take care of it for you. I am very happy with the results I am getting now blanking skis. The Scout makes it almost trivial. My fear of gouging the stone and shortening its life has since disappeared.

Using a belt to try and flatten skis is useless. You'll never get less than one degree base bevel and the bases will only approximate flat.

Thanks Doug. The skis are currently with the original shop for additional stone grinder passes. I will pick them up Tuesday. If they still aren't correct, I will make the drive to come see you.

So if I understand what you've stated, there is some "reluctance" due to a belief that the metal edges will damage the stone. However, stone grinding is still the best (and really only) method to accurately "zero" the base. In the old days of skinny skis, I wouldn't hesitate to take a flat file to the ski and use that to flatten it, but skis are too wide now to make that practical

 

[Doug Briggs]

Flat filing is a pretty slow and laborious process and of course leaves not structure.

I was reluctant to grind the edges with the stone but have since learned it isn't nearly as bad as I once thought. Railed edges are still hard on the stone, but I no longer try to 'relieve' the edges of skis that have edges that aren't 'proud'. I would use a belt or the edger to get rid of excess base edge, but once it is at the level of the p-tex I'm fine to grind the edges to zero on the stone.

 

[razie]

Don't do flat filing - it's a lot of work and easy to make a mess of the ski... This is a common mistake: they flatten out the base but don't take enough material to get to the edges. Had a couple pairs with that issue. More stone grinding did it for me, by a guy that knew what to do...

He also had an interesting technique to put the edges at 0.5 by pressure - and he got close enough. He would apply some pressure to the skis, by hand, to have the stone take some of the edge - it worked... obviously not precise, but I had very little work to do after.

Actually, I don't think it was a stone grinder - he used belts... so likely a very fine sandpaper... and then a special fiberglass belt to give it some structure back - didn't look too bad...

 

[Noodler]

Don't do flat filing - it's a lot of work and easy to make a mess of the ski... This is a common mistake: they flatten out the base but don't take enough material to get to the edges. Had a couple pairs with that issue. More stone grinding did it for me, by a guy that knew what to do...

He also had an interesting technique to put the edges at 0.5 by pressure - and he got close enough. He would apply some pressure to the skis, by hand, to have the stone take some of the edge - it worked... obviously not precise, but I had very little work to do after.

Actually, I don't think it was a stone grinder - he used belts... so likely a very fine sandpaper... and then a special fiberglass belt to give it some structure back - didn't look too bad...

Yeah, that sounds like it was highly dependent on the skill of the operator. So obviously that doesn't work as "general" advice when it comes to getting a zero reset grind.

Hopefully the guy gets it done and the skis are totally flat when I pick them up Tuesday. If not I'll be hitting Racer's Edge to see Doug and his "magic" machine.

 

[James]

In the future I would eliminate that shop. People here used to drive hours after already driving hours to ski country, to go to Edgewise in Stowe. Now that they're gone we have to deal with the same crap you're going through.
I think @cgeib used to get his skis flattened by the guy at the Abasin shop. He likes no base bevel or the tinyiest of ones.

 

[Doug Briggs]

I'll admit to having learned a lot about tuning in the past few months with regards to prepping skis prior to setting small base bevels. Recreational tunes and base bevels from 1 and up are easy, you don't need a base bevel at zero to start in order to achieve the desired flatness and base bevel. Its the sub 1 degree base bevel that is a challenge. Now it is less challenging since I've learned to sacrifice a little stone for the quality tune.

You live and learn.

 

[Noodler]

Picked up the skis last night and they are now fully flat edge to edge. In fact, the structure pattern on the base can be seen on the edges in the right light. One thing the tech pointed out was that he feared the edges may now be "case hardened" (like when you hit a rock) and that they would be more difficult to sharpen. I'm heading out soon to go file the base edges and set the bevel. More to come...

 

[Doug Briggs]

The structure in the edges is unavoidable given you want a zero degree bevel to start. By definition you are treating the edges like the bases.

Case hardening is one of the issues with hand held ceramic edgers. They don't have a cooling function like the Scout. I'll be curious to hear how it turns out for you. Did they use a simple linear structure or a 'fancier' one like a cross hatch? The deeper the structure, the more likely you are to be unable to remove it completely, especially up against the p-tex, while filing unless you are willing to file away some p-tex (and its structure) as well.

 

[Noodler]

Base bevels are now reset to 1* on my Scott Crusade and 0.7* on the Scott Neo. My Icecut files used with the Toko WC guides worked just fine. In fact the Icecut files had no issue at all biting into the edges. So no case hardening was apparent at all.

On another note, the skis were absolutely coated with whatever liquid is used to lubricate the stone. It was a kind of light green colored fluid and it dried "sticky" all over the skis. I had to thoroughly clean them top and bottom to get the stuff off. I've never before received skis in this condition after a grind. Is this just normal, but the operator usually wipes down the skis before giving them back to the customer?

 

[James]

Good point about the fluid. I assume it's wiped off. Never got a ski back covered in slime. You can see the cutting fluid gets everywhere.

 

[Atomicman]

Picked up the skis last night and they are now fully flat edge to edge. In fact, the structure pattern on the base can be seen on the edges in the right light. One thing the tech pointed out was that he feared the edges may now be "case hardened" (like when you hit a rock) and that they would be more difficult to sharpen. I'm heading out soon to go file the base edges and set the bevel. More to come...

The fact the the structure is in your base edges is going to be a problem. You need to file/polish All of that structure out of the base edge or the skis will ski like they have the worst hanging burr known to man. Don't ask me how I know!

 

[Atomicman]

The structure in the edges is unavoidable given you want a zero degree bevel to start. By definition you are treating the edges like the bases.

Case hardening is one of the issues with hand held ceramic edgers. They don't have a cooling function like the Scout. I'll be curious to hear how it turns out for you. Did they use a simple linear structure or a 'fancier' one like a cross hatch? The deeper the structure, the more likely you are to be unable to remove it completely, especially up against the p-tex, while filing unless you are willing to file away some p-tex (and its structure) as well.

Doug...I have not found this to not to be the case. Just had a pair of 188 Atomic Race Stock Redster GS ground on a big auto Montana machine yesterday. Beautiful grind and Edges were -0-...No structure in base edge. And the reason we ground them is because too much base bevel had developed. I put a .7 on them

 

[Doug Briggs]

Doug...I have not found this to not to be the case. Just had a pair of 188 Atomic Race Stock Redster GS ground on a big auto Montana machine yesterday. Beautiful grind and Edges were -0-...No structure in base edge.

I don't know how they avoid getting structure in the base Edge when they are using the stone itself to bring the base Edge to zero. I use a very fine structure to blank the ski knowing that any bevel that I put on will get rid of any structure in the edge. I am welcome to any comments from tuners.

 

[Atomicman]

I don't know how they avoid getting structure in the base Edge when they are using the stone itself to bring the base Edge to zero. I use a very fine structure to blank the ski knowing that any bevel that I put on will get rid of any structure in the edge. I am welcome to any comments from tuners.

I have only had structure in the base edges once. It was from a Wintersteiger machine. and even after beveling the things skied horribly until we further polished the shit out of the base edge.

 

[Doug Briggs]

Base bevels are now reset to 1* on my Scott Crusade and 0.7* on the Scott Neo. My Icecut files used with the Toko WC guides worked just fine. In fact the Icecut files had no issue at all biting into the edges. So no case hardening was apparent at all.

On another note, the skis were absolutely coated with whatever liquid is used to lubricate the stone. It was a kind of light green colored fluid and it dried "sticky" all over the skis. I had to thoroughly clean them top and bottom to get the stuff off. I've never before received skis in this condition after a grind. Is this just normal, but the operator usually wipes down the skis before giving them back to the customer?

We wipe the skis down when we are done servicing them to remove a dried on emulsion. I agree that it's kind of ugly to get your skis back looking like they've been on the top of somebody's car on the highway.

 

[Noodler]

The fact the the structure is in your base edges is going to be a problem. You need to file/polish All of that structure out of the base edge or the skis will ski like they have the worst hanging burr known to man. Don't ask me how I know!

Base bevels were reset, so there is no sign of the structure left since there was sufficient metal removed for the beveling. I also run a pass with a diamond stone after filing to polish the final edges.

 

[Noodler]

We wipe the skis down when we are done servicing them to remove a dried on emulsion. I agree that it's kind of ugly to get your skis back looking like they've been on the top of somebody's car on the highway.

I imagine this stuff is easier to get off before its allowed to dry. So I guess my point is that the operator in this situation should have wiped them down immediately, but failed to do so.

 

[Berlow94]

The only way to apply structure to a truly fully flat ski and not end up with structure on the base edge is dressing the stone with a structure that is margined narrower than the waist width of the ski.

Otherwise the base bevel is usually set by the shop after all of the flattening and blanking is done but before the final structure pass.