lubrication as well as help rinse away excess gunk that
otherwise loads up and hinders stone cutting and pol-
ishing efficiency.
Most technicians recommend using a 100 to 150-
grit diamond stone to initially repair rock damage on
side edges and a 200-grit aluminum-oxide stone on
base edges.
Diamond versus hard stones
Why two different stones? Visualize the surface of a
diamond stone as a flat plain studded with sharp rocky
spires that scratch the sky, versus an aluminum-oxide
stone with a surface more akin to a flat plain erratically scored by canyons. The protrusive diamonds cut
more aggressively than the comparatively flatter-sur-faced aluminum-oxide stones, even when both have
similar grit ratings. The result is that aluminum-oxide
stones don’t remove base edge, adjacent base material or base structure as rapidly as diamond stones,
thereby diminishing the chance of accidentally over-beveling base edges in the process.
Damage control
Minor damage includes slight edge dulling, scratches
or small vertical burrs. These burrs are frequently
found along front inside edges due to slapping or
“scissoring” ski tips during a race, and leave a sharp
but ragged steel lip. Left untended, these burrs can act
like tiny fins that dig into snow deeper than the rest
of the base, creating additional drag and sometimes
unpredictable “twitches” between turns — neither of
which will inspire confidence during a race.
You can detect the roughness of these small burrs by
simply running your fingertip carefully along edges.
You can also lightly mark them with a felt-tip pen to
avoid unnecessarily overworking undamaged areas.
On side edges, use a 200 to 220-grit diamond stone
in conjunction with a bevel guide to lightly lap burred
edges. Switch to a smoother 300 or 320-grit aluminum-oxide stone to do the same on base edges. Again,
stop stoning as soon as the sound and feel changes
from loud and raspy to quiet and smooth.
Polishing edges
Always polish base and side edge surfaces after every
race, as well as after performing any edge repair, fil-
ing or beveling. It takes only a few moments and will
help maintain sharp crisp edges as well as guarantee
smoother edge surfaces that glide faster and better
resist rust.
Start with a 325 or 400-grit diamond stone for side
edges, and a 400-grit aluminum-oxide stone for base
edges. Use them with a bevel guide and make light
overlapping strokes from tip to tail. Then repeat the
process using finer (600 grit) stones to repeat the
same process, finishing with light, full-length tip-to-
tail passes. Always maintain a light touch to avoid
over-beveling and edge wear.
Although World Cup techs often progress up to ultra
fine 1500-grit Arkansas stones for mirror-like results,
junior and master racers can make finishing passes on
edge surfaces using a 600 or 1200-grit Arkansas or
ceramic stone.
“A fine ceramic or Arkansas stone ‘hones’ edges instead of ‘sanding’ them,” says Justin Harvey, the alpine
coordinator for Swix USA tech/race clinics. “When
you work with a diamond stone, you are somewhat
‘softening’ the edge surface, so finish with a hard stone
to smoothly hone it to final race-ready condition.”
Top techs agree. And once this final step is done,
you’re ready to go race.
Maintain a sharp base edge using an
aluminum-oxide stone and bevel guide.
Jack Moore is the founder of Tognar Toolworks ( tognar.com), a
worldwide purveyor of ski tuning tools and waxes.
Edge Bevel Recommendations
Skier Type Base Bevel Side Bevel
Novice/intermediate 1 degree 1 degree
Advanced all-mountain 1 2
Expert all-mountain 3/4 - 1 2 - 3
Slalom racer 0 - 1/2 3 - 4
GS racer 1/2 - 3/4 2 - 3
SG & DH racer 1 2 - 3
Nitty-Gritty Details
Aluminum-oxide stones come in a wide
variety of grits. Ceramic stones are
available only in finer 600 and 1200
grits, while Arkansas stones come in
ultrafine 1000 and 1500 grits. There
are numerous brands and grits of
diamond stones to choose from. The
brands 3M and DMT have long been
popular due to their low cost and
ready availability. Diaface Moonflex,
Swix and Ski Man diamond stones
sport more distinctive circular surface
patterns and boast a higher concentration of diamonds. Accordingly, they are
more expensive, but more durable.
Maintain a Light
Touch and Clean
Stones Often
All stones can get “scored” if you use
heavy pressure or repeatedly use the
same surface area. Shift their position
regularly to avoid this, since scoring
affects stone precision and efficiency.
The backing plates on diamond
stones also vary in rigidity; some use
aluminum while others use slightly
softer plastic that can deform under
more pressure. This not only skews
cutting and polishing precision, but
can also scour diamonds off the back-
ing material, permanently damaging
the stones.
The simple remedy to these issues
is to clean stones often — gunk (fine
steel particles, base material, old wax)
quickly collects on their faces, making
them feel dull.
On diamond stones, remove the
gunk with hot water or base cleaning
solvent, and scrub the stones with a
stout nylon toothbrush until clean. For
hard stones, use a cleansing powder
like Comet or Ajax, along with warm
water and sturdy toothbrush to remove
gunk. You can also lap hard stones
(but not diamond stones) on a piece of
sheetrock sanding screen (laid atop a
flat surface) to remove more stubborn
gunk and light scoring. For the best
performance and durability, clean
stones after every tune-up.
