OK, we love buying new skis, but hate to tune them. Why? They have been ground at the factory with way too much speed and pressure resulting in surface hardened edges due to the heat from the poor use of the equipment and the base plastic is compressed and hardened also. New skis may look great, but don't be fooled.
New skis wouldn't really be a problem to tune except for one universal fact, there are always concave sections on new skis, sometimes the concavity is significant and the skis just won't ski well until flattened. Hence, you have to grind through the hardened materials to get the skis flat and establish consistency in the bevels. Basically, you have to "tear down" the factory tune to get the skis right. This can be laborious work if the ski is particularly concave.
So what is flat enough? Use your true bar and feeler gauge and check the concave areas. If you cannot pass the feeler gauge under your true bar using the .0015 gauge, it is flat enough. Keep in mind, you can see a concave base using your true bar and strong background light, but at less than .0015, trying to get if flatter is like chasing a ghost. It is just not necessary. More than .0015 (or .038mm), time to roll up your sleeves and go to work
The second analysis should be to check bevels. You should inquire when buying new skis how the factory set the bevels, you may want to duplicate them. Side edge bevel is easy and precise, base edge bevel isn't. Review the Ski Sharp instructions regarding using a feeler gauge to analyze base edge bevels. Don't be surprised if you find significant variance in base edge bevel along the edge.
With that said, do we EVER care what the factory bevels are? Nope. Bevels are a function of the way a skier skis; we tune all our skis with the same bevels, regardless of whether they are ice skis, powder skis, bump skis, or groomers. What we do is vary the degree of sharpness by how we use the Ski Sharp inserts, but the bevels are all set the same and the factory settings are ignored.
Procedures for Efficiency:
1. You first want to remove the edge metal hardening. Until it is removed, you are stuck. Files won't cut it, the Base Flattener steel blade won't cut it, even the carbide skiver in the Ski Sharp won't cut it. Only stones can eat their way through hardened metal. The green stones for the Ski Sharp are the most aggressive way to eat through hardened metal, that is why we developed them, primarily for tuning new skis.
If you know the factory bevels, set them on the Ski Sharp and get to work. If you don't, set the Ski Sharp on 1/1. Now here is the trick. You will be able to observe the green stones cutting the base edge metal by a change in the texture of the metal. Observe carefully, you will start seeing a change in the texture starting from the tip of the edge and you can watch it work its way to where the edge meets the plastic base as you continue working. As the texture changes, the hardness is being removed, it is on the surface only. You may have to increase the angle of the base edge bevel on the Ski Sharp to get all the way across the base edge as you are working if you find you are "stalling out" in making progress after a while.
Keep moving the green stones around in the file pockets, they only work when fresh, dress them frequently.
2. When you think you have removed the surface hardness, try the files. If the hardness is removed, they will start to cut.
3. Once the hardness is removed, time to flatten the base. At this point, it is not a good idea to use the steel blade in the Base Flattener. The base plastic has been compressed and it is best to cut through that hardness with a stone blade. When you see the structure of the stone blade on the base, you know the hardness is getting worked through, now you can use the steel blade. It is best to rotate using the stone and steel blades, this helps efficiency. Keep the stone and steel blades dressed and sharp, dull blades won't work here.
It is a good idea to mark the edges in the concave sections with a Marks a Lot so you know the areas of extra concentration as you flatten.
Eventually you will get the skis flat, bevels set, edges polished, and they are ready to rip. But unfortunately it can take a while.
Keep in mind, our objective whenever tuning skis is not to make them ski well. We chase magic, and perfectly tuned skis are magic. If you aren't absolutely clear that your skis are magic, they need more work. Magic, there is no other description.
So what is flat enough? Use your true bar and feeler gauge and check the concave areas. If you cannot pass the feeler gauge under your true bar using the .0015 gauge, it is flat enough. Keep in mind, you can see a concave base using your true bar and strong background light, but at less than .0015, trying to get if flatter is like chasing a ghost. It is just not necessary. More than .0015 (or .038mm), time to roll up your sleeves and go to work