Posted on 4th Sep 2011 @ 9:33 PM
Deburring is the process of removing rough burrs from the side and base steel edges of skis or snowboards every time you either file 'em or after a day of ridin' 'em on the slopes. It's done with a deburring stone. This helps keep edges smoothly sharp, and free of nicks, rust, raggedness and roughness. Compared to personal hygiene, it's somewhat akin to brushing your teeth. Dulling, on the other hand, is more like performing a lobotomy. It's usually done on new skis or boards with a file and/or deburring stone to intentionally dull (or radically bevel) base edges at the very tip and tail where skis and boards lift up out of the snow. Edges here curve dramatically in toward each other, and should be addressed so they don't unexpectedly engage in bump troughs, ruts, crusty snow or other funky condition to revector your planned line of travel downhill off in some new, wild and unanticipated direction.Yikes! Detuning refers to the subtle "massaging" of an edge's sharpness or base bevel near tips and tails to intentionally adjust performance of a ski or board. On old traditional skis, detuning behind the contact points made a skis less grabby and "hooky" for easier control...but detuning a shaped ski can make the ski more "nervous" due to shortening the effective running surface, plus the skis won't initiate turns as desired due to the decreased radius and running surface. So for shaped skis find the contact point of the tip and tail (you can do this by placing the ski on a flat surface and marking the sidewall at the points that the ski contacts the flat surface) and detune from contact point forward on the tip and contact point backward on the tail.
HOW TO DEBURR & POLISH EDGES
Maintaining sharp smooth edges on alpine skis and snowboards is an important ingredient of good performance. It ensures better grip to carve turns that provide manueverability and speed control, plus can help deliver greater glide speed for racers as well. Assuming your base and side edges have been beveled to your satisfaction beforehand, here are steps you can take to keep them in top condition.
Inspect Edges Daily
Edges get dulled to some degree every time you ride, and occasionally experience other damage due to snow abrasiveness (especially manmade snow, frozen corn or ice), snow contaminants (dirt, ash, cinders), hard objects (rocks, metal stakes, etc.) or by accidentally slapping or scissoring tips together in a turn or off-balance recovery. The extent of this damage ranges from major (bent or broken edges…ouch!), to moderate rock nicks or dings, to minor dulling, small scratches or vertical edge burrs.
If edge damage is major (bent or broken), seek a good repair shop for help…unless you’re gifted with great surgical skills. If the damage is moderate (rock nicks or dings), you'll first need to remove any ragged and glazed areas where edges have been “work-hardened” by the pressure and heat of impact, and which is subsequently too hard to cut with a file.
Stones versus Files
Stones are the best tools to accomplish this task, since files are better suited for initially cutting and establishing side and base bevel angles. Files should only be used afterwards to occasionally resharpen side edges…and never base edges, where they can all-too-easily remove too much steel and p-tex material, thereby inadvertently creating excess base bevel that can leave you feeling like a pig on ice!
Willi Wiltz (former Olympic/World Cup race service technician for Tommy Moe/Dynastar, Bode Miller/Fischer, Dahron Rahlves/Atomic, and now Shaun Palmer) also adds, “Top race skis and boards are made with edges that are thinner than normal, which means they can heat up quicker on icy race courses (especially speed events) and make p-tex base material along inside edges more prone to damaging base “burn”. Stones are ideal tools to use to help conserve edges while keeping them sharp and polished”.
Always use a stone in conjunction with an edge bevel guide to ensure you precisely maintain existing bevel angles. Make repeated light strokes over damaged edges until any glazing (shiny spots) or ragged burrs disappear. Avoid heavy pressure since your goal here is to only remove protruding burrs and superficially glazed edge surfaces, rather than unnecessarily removing underlying edge or adjacent base material and structure.
You can tell you’re done because the rubbing sound will change from a rough raspy noise to a smooth lapping sound. Stop when you reach this point to avoid removing any more material than absolutely necessary. Also, many technicians prefer to spray water or a water/alcohol mix on stones during this process to provide more lubrication, as well as help “float” away excess grinding debris that otherwise quickly loads up and hinders stone cutting and polishing efficiency.
Most technicians recommend using a 100 to 150- grit diamond stone to treat rock damage on side edges and a 200-grit hard stone (aluminum-oxide or silicon-carbide) on base edges.
Diamond versus Hard Stones
Why use different stones? Visualize the surface of a diamond stone as a flat plain studded with sharp rocky spires that scratch the sky…versus a hard stone surface being more akin to a flat plain erratically scored by canyons. The protrusive diamonds cut more aggressively than the comparatively flatter-surfaced hard stones…even when both have a similar grit rating. The result is that hard stones don’t remove base edge or adjacent base material and structure as rapidly, thereby retarding the chance of accidentally over-beveling base edges in the process.
Randy Graves (former Rossignol U.S. Team & World Cup race service technician; current Green Mountain Valley School instructor, coach and race service technician) warns, “I’ve sometimes seen junior racers unintentionally create radical 5 to 6-degree base edge bevels (versus the normal ½ to 1-degree) because they used diamond stones instead of the less-aggressive hard stones to dress them…seriously compromising any reliable edge grip in the process.”
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 together, 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 you’ll especially appreciate in a race!
You can detect the roughness of these small burrs by simply running your fingertip carefully down along edges. You may even want to 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 edges wherever you find these burrs. Switch to a 300 to 320-grit hard stone to do the same on base edges. Again, stop stoning as soon as the sound changes from raspy to smooth.
After repairing any edge damage, doing any edge filing or beveling…and always after a race…take a few moments to polish base and side edge surfaces. This will help maintain sharp crisp edges as well as provide a smoother surface that glides faster and resists rust better.
Start with a 325 to 400-grit diamond stone for side edges, and a 400-grit hard 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.
Although World Cup techs often progress up to ultra fine 1500-grit stones for mirror-like results, junior and master race needs will be adequately served by making finishing passes on both side and base edges with a 600 or 1200-grit ceramic stone, or a hard or translucent Arkansas stone.
As Justin Harvey (Alpine Coordinator for Swix USA tech/race clinics and US Ski Team needs) observes, “A fine ceramic or Arkansas stone ‘hones’ edges instead of ‘sanding’ them. 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.” All top techs unanimously agree. Once this final step is done, you’re ready to go ride.
PROTECT SKI & SNOWBOARD EDGES
To protect ski and snowboard metal and top edges, as well as car seats and the inside of ski/board travel bags from amage, buy 2 to 4 pieces of foam pipe insulation (for 1/2" pipes) at any hardware store. Fit these over your steel edges, as well as around tips and tails. Once your ski or board is in a travel bag, it should stay in place. If not, wrap some cord or bungy straps around them to hold 'em in place. In some cases, you might have to cut the insulation to accommodate bindings or ski brakes...otherwise this is a good cheap way to protect your gear.
I usually toss my snowboard in the back of my pickup after a hard day shreddin' the slopes. To help protect the base and edges from getting messed up back there, I clip two rubber bungy cords around the board...one up near the tip, another back near the tail. This keeps the base and edges lifted up off the truck bed and from getting ground up as
bad as they would otherwise.
-Simon Coope, Brooklyn, NY
OTHER RELATED TIPS
IMPORTANT NOTE- Always Use Light Pressure and Clean Stones Often!
All stones can get ‘scored’ with indented wear lines if you use heavy pressure or repeatedly use the same surface area…so shift their position regularly to avoid this, since scoring affects stone precision and efficiency. The backing plates on different 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 backing material, permanently damaging the stones.
The simple remedy to these issues is to clean stones often...since gunk (fine steel particles, base material, old wax) quickly collects on their faces, making them feel dull. On diamond stones, remove this using hot water or base cleaning solvent, and scrub them with a heavy-duty nylon toothbrush until clean. For hard stones, use a cleansing powder like Comet or Ajax, along with warm water and a heavy-duty 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 best performance and durability, clean stones after every tune-up.
WORLD CUP TECH TIPS
After filing or touching up steel edges, always deburr and polish the edge for smoothest, sharpest, most efficient results. When working on slalom race skis or boards, final polish the side edges last...this will lend just a little extra sharpness for better edgehold when cranking lots of quick tight turns. When working on GS or speed skis, polish the base edge last instead, since the extra vertical sharpness you want for slalom can actually create a little more drag...which can reduce speed in faster events.
- Pam Warman, U.S. Ski Team Technician
DOWNSIZING A POLISHING STONE
Ceramic stones are an integral part of my tuning kit, but I like to cut them in half so they're shorter and can be carried around easier in a pocket while skiing or riding. To do this, I score the stone all around the middle using an edge of a mill file. If scored deeply enough, it can then be "snapped" cleanly in half using gentle pressure.
-Dan Crites, Okemos, MI
Most tuners always remove the sharp burr on their ski or snowboard edge after any beveling or sharpening...but some slalom racers and extreme skiers feel that a small burr left sticking out to the side may help increase edgehold on harder snow surfaces...at least until the snow abrades it off.
-Jim Deines, Precision Skis, Frisco, CO
Steel edges are work hardened when they strike or run over a rock...not 'case hardened'. Case hardening is a process where an iron-based material is heated while surrounded by a carburizing atmosphere. This increases the carbon content in the skin of the material which hardens it...while leaving core material untouched. Work hardening is often used to harden the surface of a material which has been annealed by shot peening (blasting it with thousands of BB-like shot blasts). Most materials will work harden if abused...such as a wire coat hanger that is bent repeatedly.
-John Scott, Okermos, MI
Before doing any service work on a pair of skis, run your fingers lightly over the top edges. Use a file to smooth out any rough spots so that you won't get cut while working. This'll make skis and snowboards a lot safer to handle, and save expensive ski clothing from unnecessary rips and snags. Also, clean off the tops of skis that you're servicing for friends or customers. Use a mild base cleaner to remove old peeling decals, price labels, sticker backs, and dirt. Remember, your friends or customers will be enjoying expertly-tuned equipment...but they'll be looking at the tops a lot more than the bottoms.
-Jim Deines, Frisco, CO
I keep a spray bottle of water on my workbench. I use it to wet diamond stones before deburring and polishing steel edges, which helps keep the stones from clogging up with residue as quickly. I also spray my bases with it to help reduce static build-up when brushing the structure open after hotwaxing and scraping.
-Rick McCowan, Princeton, MA
You can clean deburring and whetstones of grunge and debris build-up by rubbing their faces with a gummi stone...this can really help extend their life.
- Al Duberchin
I often use diamond stones to tune my edges and have found isopropyl alcohol makes a good cutting fluid (instead of water). I keep it in a spray bottle for easy application, and found that it evaporates quickly, doesn’t encourage rust, and doesn’t freeze in an unheated shop or travel tuning kit.
Keep a small diamond or hard stone in a pocket of every ski or snowboard parka/shell you own, so you'll always have one handy to deburr edges whenever you nick a rock or scissor your edges when on the mountain.
-Dave Irons, Westbrook, ME
DETUNING SKI TIPS & TAILS ON OLD (TRADITIONAL, NON-SHAPED) SKIS
Slightly dull inside edges back 0-5 cm from tip and tail of slalom skis.
Slightly dull outside edges back 5-10 cm from tip and tail of slalom skis.
Slightly dull inside edges back 5-10 cm from tip and tail of GS skis.
Slightly dull outside edges back 10-15 cm from tip and tail of GS skis.
Please note, however, that a little dulling goes a long way...do it sparingly.
A quick note about our "grit ratings":
In the industrial world, there are different grit ratings that apply to different abrasive products...which can be a bit confusing for most common folks. For simplicity's sake, we've tweaked things just a bit and applied the same rating system to all abrasive products we sell. This means, for example, that a 600-grit ceramic stone will match the smoothness of a 600-grit diamond stone. Likewise, a 150-grit sandpaper will match the roughness of a 150-grit diamond stone, etc.
This simply makes it a little easier for you to anticipate the results you'll get from whatever abrasive or polishing tool you buy from us. Just be aware that the rating system you see printed in our catalog will sometimes differ from the grit rating printed on the actual product (diamond stone, etc.) that you receive...but rest assured you have received the product you wanted.