While you have your files out... Check files for sharpness and damage. Buy a new file each year and mark the old one with a "W" for "working" file. Use this file for odd jobs and save the new one for your edges.
Make your tips and tails aerodynamic (I not talking about the edges, but rather the actual top/bottom of your ski/board tip or tail). Some skis are squared off. Take the working file and round off the edges, then smooth with 220-grit Silicon-Carbide (SiC) sandpaper and polish with 400-grit SiC.
Remove rough areas on the top surface (over the entire length) of the ski/board with 400 grit silicon carbide sandpaper.
Check for Flatness
Hold a true bar to the ski at 8-10 points along its length.
You are looking for a base that is consistent along its length, neither high nor low compared to the edges.
Base material should be free of waves.
Keep in mind... After you set your edge angles once, use diamond or aluminum oxide stones to sharpen, not metal files. And sharpen from the side only. This will be explained in detail below; it is mentioned here as not to be overlooked.
A side bevel that is higher in degree than the base bevel gives an acute angle. This gives more grip on hard snow surfaces. General recommendation for serious racers and J3/J2 level.
90 Degree Edge Bevel
A 1 degree base bevel and a 1 degree side bevel give a 90 degree total edge angle. This is a good starting point for beginning J4/J5 racers.
Base Edge Thoughts
The amount of base edge bevel will affect the ability of the ski/board to pivot on the snow. The more base edge bevel, the easier it will be to pivot or slide from side to side. Once you set the base edge angle, you can't go back to the original because of the base material. With a new pair of skis the non-race skier may wish to start with a 0.5 degree bevel. If you need to resurface past this point, you may need to stone grind the base to bring it back to flat so you can re-establish the base angle. So once the base edge bevel is set, maintain it as long as possible using diamond and gumi stones.
The bevels cited below are good starting points. If the skis hook up on turns, increase the bevel by a quarter or half degree. A woman may wish to start with smaller angles.
Suggested Base Bevel Angles
Slalom -- 0 to 0.5 degrees
GS -- 0.5 to 0.75 degrees
Super G -- 0.75 to 1.0 degrees
All Mountain Expert -- 0.75 to 1.0 degrees
All Mountain Novice/Advanced -- 1.0 degree
Snowboard Beginner -- 1.0 to 2.0 degrees
Snowboard Intermediate -- 1.0 degree
Snowboard Freerider -- 1.0 degree
Snowboard Spinner -- 2.0+ degree
Snowboard Halfpipe -- 1.0 to 2.0 degrees (tip/tail); 0 to 1.0 degrees (underfoot)
Snowboard Boardercross -- 0 to 1.0 degrees
Snowboard Slalom -- 0 to 0.5 degrees
Snowboard GS -- 1.0 degree
Side Edge Thoughts
Side edge beveling will give the skis more grip on the snow surface. Higher angles should be reserved for experienced racers; if the angle is too high the ski can "rail out" on a less experienced racer. Typical angles are 1.0 to 3.0 degrees. Less angle equals less grip. Slalom angles can be 3.0 to 5.0 degrees; downhill up to 3.0 degrees. A racer should start at 3 degrees. Keep in mind:
Higher angles are quicker to dull.
An aggressive edge (high angle), may be more difficult for lighter racers (young kids or women) may make it more difficult to recover from being up on the edge.
Which edge tool?
A multitool (side & base or multiple angles in one tool) or dedicated tools (one tool for each angle)?
Multitools (see image example at the bottom of this page) are more convenient and simple to use. They provide precise results even for the novice. This is a great choice for the beginners and the advanced model is a tool that will do everything a casual skier/boarder will need to do for a lifetime, and is a great choice for a family with skiers/boarders of different ages and sizes. A disadvantage is they may be restricted to use only certain size stones.
Fixed angle bevel guides are devices that tend to be dedicated to one angle (though there are some models with shims that are more flexible). It's advantage is that it can use any stone of any size. You have a greater feel for the cutting process with dedicated tools. The disadvantage is cost, but it is a necessary one for the serious racer.
When to edge race skis...
If the base becomes worn or requires base repair.
After the ski has been tuned on a stone grinder.
After each training session the side edge should be touched up with a fine diamond stone followed by a ceramic stone or Arkansas stone.
When burrs or nicks occur.
Don't tune the base edge between stone grinds, just maintain it with fine stones. Remember every time you use a file on your edge, it gets thinner; eventually you will reach a limit.
Tips on Edge Tips
The edge near the very tip where the ski turns up should be beveled, but the tools don't work well up there. With the grit side on the inside, fold a piece of sandpaper into fourths and use it as a file guide to bevel the edge so it doesn't catch. Make sure you don't file the base.
Base Edge Tuning
Mount bases in a vise on a flat plane.
Use an 8" hard-chromed file in a specific bevel file guide.
NOTE 1: Files are made to cut while being held at angles between 45 & 60 degrees. Find the angle that works best for your file. Use a sharp and straight file; dull or bent files won't cut smoothly, will require more pressure and skew the bevel. Hardware store files are made of softer steel (Rockwell hardness of 45-52) and are not as good as a quality ski-tuning file with Rockwell hardness ratings of 65-68. The harder file will cut better, with less pressure, and in turn last longer.
Work on the edge that is away from you (file the far edge from where you are standing).
Pull (don't push) the file toward you as you work backwards from tip to tail.
Use short, repetitive slightly overlapping strokes.
If you hit any case hardened areas on the edge (it will feel like a bump), use a black (DMT or Moonflex) then a blue DMT or red Moonflex diamond stone to remove it.
TIP: If you blacken the metal with a marker, you'll know you're done when the entire edge is shiny.
NOTE 2: Be careful not to get metal filings embedded into your base. You can use a non-residue tape but keep in mind that this changes your angle slightly. Better to just keep some fiberlene paper on hand and brush it away as you work.
NOTE 3: Do not file into the base material.
Polish with coarse (DMT blue or Moonflex yellow), fine (DMT red or Moonflex white) then x-fine (DMT green or Moonflex blue) diamond stones.
A better choice for base edges is an aluminum oxide stone. They don't cut as quickly and reduce the chance of over beveling. Start with a 400 grit and move to finer (higher number) grits.
NOTE 4: The goal is to increase performance by polishing the edges. There are small burrs on the edge after filing. Polished edges are faster and sharper.
NOTE 5: Polish in both directions (back & forth) with the red/green stones.
Finish with light, full-length tip to tail passes.
For an even finer polish follow up diamond polish with an Arkansas stone; it will "hone" the edge surface rather than "sand" it. When you work with a diamond stone you are somewhat "softening" the edge surface; removing this softened surface with a fine hard stone is honing.
A magnifying glass is handy to examine the edge structure; you are looking for a mirror image.
Base Bevels (Quick Notes)
Base Bevels (Extended)
Side Edge Tuning
Mount the ski side edge up with base facing away from you.
NOTE 1: Do not over tighten the clamp on the ski base.
NOTE 2: You may need to scrape away some of the ski material, or sidewall in order to attain the filing angle you desire. Use a sidewall cutter for this. Keep in mind that this surface should be smooth and polished after cutting. See Sidewall Cutting.
File edge at desired angle in the same manner as you did the base edge.
Polish with coarse (blue), fine (red) then x-fine (green) diamond stones.
NOTE 3: The goal is to increase performance by polishing the edges. There are small burrs on the edge after filing. Polished edges are faster and sharper.
For an even finer polish follow up diamond polish with an Arkansas stone or a ceramic edge stone.
A magnifying glass is handy to examine the edge structure; look for a mirror finish.
Go back to the base edge and re-polish with fine diamond stones.
Deburr the edges with a gumi stone by lightly running it along the edge (tip to tail) at a 45 degree angle.
NOTE 4: DO NOT DULL!
Side Bevels (Quick Notes)
Side Bevels (Extended)
Suggested Side Bevel Angles
Slalom -- 3 to 4 degrees
GS -- 2 to 3 degrees
Super G -- 2 to 3 degrees
All Mountain Expert -- 2.0 to 3.0 degrees
All Mountain Advanced -- 2.0 degrees
All Mountain Novice -- 1.0 degree
Snowboard Beginner -- 0 to 1.0 degrees
Snowboard Intermediate -- 1.0 degree
Snowboard Freerider -- 1.0 to 2.0 degrees
Snowboard Spinner -- 0 degree
Snowboard Halfpipe -- 1.0 degree
Snowboard Boardercross -- 1.0 to 2.0 degrees
Snowboard Slalom -- 2.0 to 3.0 degrees
Snowboard GS -- 2.0 degrees
De-tuning affects the the turn shape, the less dulling, the truer the shape of the turn to the side cut.
De-tune less for a sharper turn radius.
For an aggressive turn use less de-tuning (about 2 in. or 5 cm).
Adjust the sharpness according to snow conditions with the gumi.
For icy conditions keep it sharp.
Control the degree of detuning in with the gumi. Use different pressure to transition the detuning between regions. Transitioning the de-tune region with different levels of dulling ensure that there isn't an abrupt change in sharpness.
Stay sharper on chemically treated snow.
Detuning Skis for Riding in the Park
Keep edges sharp without wearing them down!
After you set your edge angles once, use diamond or aluminum oxide stones to sharpen, not metal files. Substitute a blue DMT or yellow Moonflex diamond stone to start and follow up with finer stones.
A file will wear down your edges - the stone will sharpen without severe metal removal.
Sharpen your edges on a weekly basis (nightly during races) by using the diamond stone on your side edge only (unless there is damage).
You don't need to use the file again unless you change the angle or have edge damage.
To repair severe edge damage you may need a gray/black DMT or black Moonflex diamond stone.