I want to learn to sharpen my blades freehand (tired of kits and depending on others who sharpen my knives) and my guess is that sandpaper + leather storp would be a good first way to learn, cause it's cheap, it requires manual skills (which is always stimulating and rewarding) and since I am not that "obsessed with edges" myself (at least not yet) my goal (for the moment) is not perfection...just a good clean edge that fits my needs (even tho I assume there's no really better system, just better operators).
Don't want to add too many threads on this forum, so I'm posting here and I'm sure u will be able to give me a big help and useful answers.
It's an affliction that strikes without warning. You'll never see it coming, then you'll wake up, one day, and it's too late. You're hooked.
Do u think I should start with edge trailing or edge leading? and why?
Definitely edge-trailing, when starting out with sandpaper on a soft backing (leather, mousepad, etc.). And at least while you're developing the 'feel' for it, I'd recommend edge-trailing with the hard backing, too (such as on wood or glass). When you've gained a feel for maintaining proper angle and pressure, I think it'll feel more comfortable to you to try edge-leading on hard backing too.
is it better to start with sandpaper on "smoothest" surfaces (leather, mousepads, etc) or on wood? why?
As I mentioned above, I believe edge-trailing to be very easy to learn, when starting out. For this reason, it's all-the-more appropriate to start with soft backing. It's a little more forgiving to inconsistency in angle & pressure so, if your technique is a little bit off, it won't do as much damage as quickly, as will be the case if using poor technique on a hard backing.
and most of all, how do I manage the angle when sharpening on sandpaper? do u use any "help" or just use ur eye and hands?
Start out very conservative. Keep the angle as low as possible, and pressure light. It helps, when learning it for the first time, to mark the bevel with a black marker (like a Sharpie), and inspect closely, with a magnifier, where the ink is being removed as you work. If you see the ink coming off at the shoulder of the bevel, but not the edge, your angle is too low (shallow). If, on the other hand, you see ink coming off only at the VERY edge, but not at the shoulder of the bevel, your angle is a little too high. Make a few passes on the sandpaper (maybe 3 to 5), then inspect. Keep working this way, and you'll soon get a feel for the correct angle.
As for pressure, always keep it light. I think a reasonable amount would be similar to wiping some peanut butter from the edge of your knife, as if there were a paper towel on your backing, instead of the sandpaper. That's a good starting point. As you work, you'll begin to get the feel for it. If your hands are getting sore/fatigued, you're using too much pressure. It should be smooth & comfortable. If you feel like you need to bear down on it, to remove metal effectively, that's your cue that you probably need to select a coarser grit. Let the grit do the 'grunt' work.
At the coarsest grit stage, it's important to make sure you've completely apexed the edge, before moving to the next grit. This usually is indicated by forming a burr/wire edge. You should use good magnification, under bright light, to help you see the burr. Experience, over time, will allow you to 'feel' for the burr as it forms. But, when starting out, I truly believe it's best to actually SEE it. Once it's formed, the following stages are all about reducing the burr and refining the edge (making the scratch pattern finer). As the edge becomes more refined, and you progress through the higher (finer) grits, reduce the pressure even more. By the time you've reached the finest grit, pressure should be feather-light, as if using the edge to gently brush some some dust off the sandpaper.
I'd also recommend starting with a very fine grit (maybe 1000/2000). Especially for general maintenance & touch-ups (if stropping doesn't quite do it), this will do fine, most of the time. And, starting at a finer grit will obviously do less damage, if you're still trying to figure out the correct angle and pressure. The coarser grits (400 and below) are for relatively heavy metal removal. If your edge is already in pretty good shape before you start, they'd be overkill, most of the time (UNLESS you intend to completely reshape the bevel anyway).
I have read the very clear and useful thread about stropping on this forum, so I will take that as a guide for stropping...but I need to pass through sandpaper before
This may sound a bit strange, but I actually 'trained' my hands for the sandpaper method (edge-trailing), by learning to strop properly beforehand. I didn't plan it that way, but was OBSESSIVE about learning to strop. One day, out of the blue, it just seemed natural to put a piece of sandpaper on my strop block, and go for it. My hands were ready for it. It's exactly the same motion/technique as stropping, but at a coarser grit.
