Blade fabrication Edit
Blades are commonly made in 1/4 inch lengths. Blades also have different widths as well as different configurations of the "rocker" (spinning area) and toe picks. These all have major effects on the way a blade feels, although usually a skater can adapt to a different type of blade in a relatively short amount of time.
Figure skate blades start out in three separate parts: The toe plate, the heel plate, and the part that actually does the work on the ice. These are punched out on large presses. The blades are blanked out of long strips of steel which vary in carbon content depending on the quality of the particular skate blade that is being made; for example, a recreational blade will have a lower grade of steel than a more advanced blade. Although the steel used for all blades hardens to the same standard, the better grade would keep its edge longer in similar conditions.
Before the three parts are put together to make the skate the blade section is hardened. This is done in large quantities hung on a frame and lowered into a high temperature salt bath for a set period of time to be evenly heated and while still glowing red are quenched in an oil bath. The shock of the sudden decrease in temperature causes the steel to harden . However, the hardness at this stage is too brittle, so the blades (still on the frame) are put into another salt bath of a lower temperature to temper to about what is called 60 degrees on the Rockwell scale. When cooled they are removed from the frames fed into a machine that grinds them to a set thickness.
The toe and heel plates (already ground) are then brazed to the blade. There are two methods of joining the parts together. Many blades are silver soldered. This is a fairly low temperature braze achieved by electrical coil induction which causes the heat from the brazing to travel down onto the blade reducing the hardness to about 40 degrees Rockwell for about half way down the blade but leaving the lower "working" half (about 5/16") still at 60 degrees. Some top quality blades are hand brazed with bronze. This operation creates a lot more heat; therefore the blades could be somewhat irregular in their hardness. To remedy this, they are set into an induction coil, electrically heated, re-hardened and tempered about halfway up the blade.
It is possible to tell if your blades are hand brazed. If you look at them you will notice that where the toe and heel plate joins the blade there is a very large radius. This method is very strong. Silver soldered skates will have a small bead of braze so the radius will be much smaller. However silver solder flows well and fills gaps readily. So, whichever method is used there will still be 5/16" or more of correct hardness.
After the blade is assembled and chrome-plated (to protect the metal from rust), the profile at the bottom of the blade is ground on and the chrome is removed from the edges by grinding, so that hardened steel and not chrome is at the working surface. This is the line that you see on each side of the blade edge. There is of course extensive polishing and inspection before shipping.
Buying new blades Edit
The blade length denotes the measurement from the front of the sole plate to the back of the heel plate. Measure the length of the boot sole from toe to heel and fit blades which are 1/4 inch less in length.
When it comes to buying blades, the same advice given for purchasing new boots applies: you should buy well-built and equipment appropriate to your level. Skaters gradually upgrade their equipment as their needs change, for example a skater may need to upgrade skates when they move from basic skating to their first jumps or from double to triple jumps.
Top of the line blades are designed for very good skaters. Advanced free-style blades have a longer radius and have large toe picks. Also, the portion of the blade that is used for spinning is smaller than on intermediate blades; that means that unless you are perfectly balanced and positioned going into and during the spin you will start rocking on the blade.
Just because the MK Gold Stars are very expensive does not mean that they are inherently better blades than MK Pros or Phantoms. Starting with MK Pro and Coronation Ace lines, the blades are all made using much the same materials and manufacturing process, as described above. To put it succinctly, certain blades are more expensive simply because of supply and demand and a few slight design modifications like side honing, or coating with metals other than chrome which makes them more costly to produce.
Three ways of checking used blades Edit
- The best way to determine the wear on blades is looking at how thick the dull strip is on the sides of the blades along the edges. These strips were three or four millimeters when new. If they are now thin, then your blade has been sharpened many times. The concern here is that the rocker may be distorted after many sharpenings, and it is almost impossible to restore without specialized equipment.
- A second test consists in holding the skate upright on a table and rocking it forwards until the lowest toepick makes contact with the surface. The blade should also be touching the table within one or two inches of the toe pick. If the blade touches the table further back, it means that the toe-pick is too low (probably a consequence of successive sharpenings). If the blades touches closer than 1 inch, the master toe-pick may have been ground off. In this case, the blades will be useless for learning spins and jumps.
- The third test is to ask the skate sharpener at your rink to examine the blade. They can tell you if the blade is bent, incorrectly mounted or obviously damaged by abuse or bad sharpening.
If the only problem is that the toe pick is too low, ask your shop to grind it somewhat to raise it. Never have the bottom (master) tooth ground off your blades unless you only intend to use them for figures!
Mounting the blades Edit
Skates with improperly mounted blades can be virtually impossible to skate on. The blade must be correctly positioned and aligned on the boot. To avoid twisting the blade, the boot heel and sole contours must match the blade mounting surfaces. If not, the surfaces can be trimmed with a rasp, or shims can be added between the blade and boot. Briefly, this is how your skate shop will mount the blades:
- Find the center of the tip of the sole and the center of the heel and draw a line joining them.
- Place the front of the sole plate of the skate blade in line of the front of the sole of the boot, and maintain the skate blade along the line drawn. This will place the blade between the big toe and first toe.
- Screws may be placed only in the slotted holes, so that you can try them and make minor adjustments (a blade position slightly closer to the big toe is sometimes favored). Do not do a lot of jumping on the blade until the best position of the blades has been found and more screws have been inserted.
Blade warping Edit
Warping of the blade can happen when the front or back pair of screws are tightened on the temporary mounts, skewing the blade from front to back, or if the holes for the permanent mounts are not positioned perfectly.
Another likely cause is that the heel might not be perfectly level or flat with respect to the front of the boot: On old boots, old screw-holes may have created bumps on the heel. If the boots are new, they might have been manufactured with an uneven heel. Such a heel will twist the blade.
Checking for mounting problems Edit
If you have trouble getting good edges, first have the blades checked to make sure they are straight, properly sharpened and mounted perpendicular to the sole. If the problem persists, have someone watch to see if your blades "make snow" as you try to skate on the edge in question. If they do, this may point to a mounting problem which can be corrected by a slight shift of the blade mounting. You will need to tell the person remounting your blades which edges you are having trouble with.
You can also check if your blades are mounted correctly by yourself (you need recently sharpened blades for this test to ensure that the edges are even):
- Find a clean patch of ice
- Gather some speed and glide on two feet on a straight line.
- Keep your body upright. Your feet should be directly under your hips. Try this several times, both backwards and forwards
- Go back and look at the traces: if the blades are set correctly you should get a set of double lines for each foot. If one of the lines is consistently thicker than its mate, or if there is only one line, it means that your weight on that blade falls predominantly on the edge tracing that line,i.e., the blade is unbalanced.
- If you are leaning mainly on the inside edge, have the blade shifted to the inside and vice versa. You probably only need a small shift; try moving it by 1 or 2mm and then repeat the test
Rocker is the curve of the blade from toe to heel, and is based on the arc of a circle with a given radius. Thus, if you drew a circle with a 7 foot radius and placed a blade with a 7 foot rocker along the inside curve of the circle, it would line up with the tracing, at least at the rear (tail) of the blade. The curve at the front, behind the toe pick is somewhat sharper. It is this difference of curvature which allows you to turn and spin on the front of the blade.
- The smaller the radius, the more rocker (amount of back and forth rocking motion you can get when standing on the blade) it has. With small radius blades, you can do turns with less chance of falling as there is less blade on the ice. For the beginner, a 6 foot radius is fine as, among other things, it is very forgiving in the toe pick department: You really need to lean way forward on them to catch the picks.
- The bigger the radius, the flatter the blade. This will generate more speed as more of the blade contacts the ice. You will want a flatter blade (7 foot or more) as you become more advanced. When you start learning jumps, you will find that you need good edge control. Because you have more blade on the ice, you can start to prepare your body position for take-off without falling off the edge so easily.
Grind or hollow Edit
Hollow or grind refers to the concave surface on the bottom of a correctly ground blade. A small radius creates edges that will dig deeply into the ice, while a larger radius digs in less, but glides more freely. A hollow with a 5/8" to 3/4" radius is recommended for beginners and all-purpose skates. This hollow will allow you to sense how a proper edge should feel, and at the same time be forgiving in things like T-stops. The weight of the skater will also affect how deeply it should be ground: Usually children will need a deeper hollow than fully grown adults.
Finally, the width of the blade is yet another factor to consider: A deep hollow with a 3/8" or smaller radius will be very unforgiving on freestyle blades, unless you are a child or have a very petite frame. This type of grind may yields crisp and fast 3-turns, ability to hold a very deep edge when landing jumps, and allows for fast spins if they are well centered. A small radius is favored for dance or hockey blades; these types of blades blades are narrower than freestyle blades and they need a deeper grind to get the same grip on the ice.
A shallow "figure" hollow with a 1" or larger radius will require a more correct lean to prevent skidding and requires more frequent sharpening, but yields an easy glide and clean tracings.
Advanced blade features Edit
The K-pick design consists in a set of extra 3-4 picks to the side of the standard toe-picks. This feature is supposed to provide more control and better anchorage to the ice on toe-jumps. According to blade manufactures, the jump height can increase by 5-10% and the jump length by about 20% on toe loops and flips. No significant improvements in height and length have been reported for the Lutz, although the improved stability on the take-off supposedly makes for more consistent jumps. Many freestyle blades models, particularly at the high end range, are available with K-picks.
Side honed, parabolic and tapered blades Edit
Most skating blades have the same constant width along its full length. However, some advanced freestyle figure skating blades have a concave section known as "side honing". Side honed blades are thicker at the stanchions and the edge stripe and thinner in between. You can tell side honed blades because reflections appear inverted.
Another modification to the edge profile found in advanced blades is "tapering". Tapered blades are thicker at the front near the toepicks and thinner at the tail, i.e. the edges are not parallel. Parabolic blades are thinner in the middle section and thicker at both ends. Some models or custom made blades can be both side-honed and tapered. These modifications make the blade lighter (because of the removed steel) and supposedly provide a better grip on the ice. Not surprisingly, the more laborious manufacturing process translates in a higher price. Whether they actually provide any real significant advantage is a matter of discussion.
Blade sharpening Edit
Take your skates to a pro shop or ask some regular skaters at your rink where they get theirs sharpened. Skate sharpening is not a do-it-yourself project! Skates are expensive and it only takes one bad sharpening to turn them into scrap metal!
Skates properly sharpened will have a smooth concave grind accurately centered along the length of the blades, edges squared (parallel to the bottom of the boot) and level with each other (inside edge at same height as outside edge) for the length of the blade. Proper sharpening will maintain the correct rocker for the life of the blade.
- Freestyle sharpenings will have typically a 1/2" radius concave grind and will be in a sharp condition. The edges of a deep freestyle grind have the great advantage of holding jump landings on hard or soft ice and also will outlast a shallow grind by a considerable amount of time. They will also hold landings on missed jumps and give the skater that extra split second to catch their balance and avoid unnecessary falls. A sharp deep grind takes a little effort on the part of the skater to adapt but is well worth the effort and once adapted to it will be no problem after future sharpenings.
- Figure sharpenings will have 1 1/4" radius concave grind and will be in a medium sharp condition. The figure grinds are extremely smooth and flow freely on the ice. More shallow (greater radius) grinds have extreme flow on the ice but are usually suitable only for the more advanced skater, since it is hard to hold an edge without the proper lean.
- Combination sharpenings will have 3/4" radius concave grind and will be in a medium sharp condition so that the skater can skate
figures with ease or they can be used for general skating. The grind will be of smooth finish and will flow quite freely on the figures (although not as freely as a true figure grind). This grind can be used for all jumps and spins and will hold well while blades are in a sharp condition. This grind is also very suitable for occasional skaters and some dancers; and is also good for adults to start with.
Skates should be resharpened before they become so dull that you begin to slip on hard ice. This will also minimize the adjustment you need to make to your newly sharpened skates. Nicks in the blades should also be attended to. Bad nicks in the edges will ruin the finest sharpenings.
When the blade is ground down a long way after many sharpenings, the relationship between the bottom pick and the blade edge should be maintained by removal of steel from the pick. There should be about 1/2" lift at the heel before the pick makes contact with the ice. Just because your blades are ground down past the line of chrome plating, that is not an indication that you need new ones. There is still lots of life left as long as the sharpener replaces that "line" and adjusts the pick height.
Beware of how some shops do their sharpening: Some shops flat-grind the blade first, and then hollow grind. This wears the blade at an accelerated rate.
Blade maintenance Edit
There are two kinds of blade covers, hard rubber/plastic guards and terry-cloth "soakers". The plastic guards should be worn any time you step off the ice. Even rubber mats or carpets accumulate dirt and grit from the shoes of pedestrians, and this grit will nick and round off the fine edges of your blades much faster than gliding across the ice. Do not leave the guards on your skates between sessions as they will trap water and cause your blades to rust.
The cloth soakers are put on after you have removed your skates and wiped them dry with a rag. They protect your blades from bumping in transit and wick away any condensation so your blades will not rust. If you still have problems with rust or want to store your skates for a longer time, rub a drop of oil or Vaseline along the bottoms of the blades.