The other day I found a pair of 80's(?) vintage Fischers in someone's trash (they have "high molecular sintered racing base" and "twin cam" bindings!). I thought -- hey! -- I can use these to practice tuning on. (As I was tossing them into my car, the previous owner popped his head out the door and called to me, "Be careful when you use those things....the guy in the shop told me they're not safe to ski on any more!" ). As if! Like, he-llo!
So, here they are, in all their rusty-edged glory. No need to scrape the wax off before working on them....they look like they never got a coat of wax in their life!
[Disclaimer: Duh....this is sort of a diary of my experiments, done for my edification and amusement, certainly not an instructional manual. Although there may be educational tidbits scattered throughout, it goes without saying that no innocent soul should blindly copy anything I do, especially on a "real" pair of skis!!! ]
That said, I checked them with my true bar, and found pronounced concavity at the shovel....
getting progressively less toward the binding, and becoming essentially flat from the binding to the tail.
Ok, this looked like a good candidate for my new panzer file. After taking a few strokes with just the file in my hands, it seemed to me like the file was bending, despite my trying to put pressure in the middle with my thumbs. So to eliminate that, I screwed the file to a piece of wood to keep it flat. (Of course, there's no guarantee the wood is really flat either. That's something I should check before using this "for real".)
I quickly found out is that the cutting edge is the convex side of the curved teeth, not the concave side. The following picture shows the direction I had to hold it when pulling towards me.
And, unlike a regular file, you must always hold it diagonally, not at right angles across the ski, otherwise the teeth can make gouges in the base. This makes it tricky to use near the shovel. If you hold it diagonally over the area where the shovel starts, you can make horrible gouges! (Guess how I found that out? Can you say, "I'm so glad I didn't try this on a good pair of skis" three times fast? Sure you can.)
Yet, you can't hold the panzer file at right angles like you would a regular file in this region either. So I just left that area alone, planning to return to it when I did the finish filing with a mill file. I think if I ever do this on my real skis, I would put a piece of masking tape where the shovel starts to turn up, as a warning to keep the file away from there.
After a while I got the hang of it and got the base reasonably flat. The panzer file is very sharp and really does cut very fast, almost like a knife through butter, terrific for this sort of application. One thing I noticed when checking with the true bar is that I must have been bearing down harder with my right hand, since I was cutting more deeply on that side. So I took some strokes the other way, from tail to tip, and that evened it out.
Like the shovel, the tail area where the ski turns up was another region in danger of gouging. Lesson: stop before the tail and handle it with a mill file at right angles.
Finally, I used my mill file to finish the job, holding it at right angles near the shovel and tail, and diagonally in between. I found it is quite easy to bend what appears to be a very stiff file, causing unintentional bevels. I really had to concentrate on pressing strongly with my thumbs in the middle, and just pulling (not pressing) with my hands on the overhanging ends of the file.
Another thing I learned is to keep cleaning the file and ski while filing, since I did manage to rub quite a bit of rust and dirt into the base in such a way that it wouldn't easily come off.
The end result? Still a bit of concavity at the shovel, but much better....
....and flat everywhere else
I still have one sacrificial ski to go, so I'll see if I can do a perfect job on that one before (if ever) victimizing my real skis
Edited by renenkel - 2/20/12 at 3:53pm