Hand-sanding question

C

Chant

Joined
Jan 27, 2006
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279
I'm getting better at putting a hand-sanded finish on knives, thanks to all the advice available on bladeforums. I've tried various tricks I learned here to keep things flat, like using a block of micarta, etc.

Despite improving, I still have problems with "washing out" my lines. Part of the problem begins with grinding (I'm still learning, and still have lots of flaws), and part, I assume, is my own impatience sanding, and loss of control when I get "rubber-arm". All this should improve over time.

In the meantime, however, when I do accidentally round out lines I want crisp, what is the best way to recover? If I try to re-establish the sharp lines with sanding, it will take forever. If I go back to the grinder to flatten things up, I fear I will get into a cycle that ends up turning my knife into an awl.

What do you experienced guys do if you mess up?
 
If its a line between primary bevel and the flat on the spine, you can do all the primary bevel sanding, then do the flats. The flats should crispen your bevel line if you do them carfeully. I think this one is just patience and practice! You could also put a limiter on your sanding device. Figure out the angle of the bevel, and put something at a heaight where it wont allow you to lower the sanding fixture enough to wash out the line...not sure if anyone even does that, but its an option.....
 
Thanks, I'll try that. It is not just the bevel and flat, though, it is also the edge of the spine and the flat.

I think I've found my main problem, though -- it is my workbench, which is a banquet table from Office Depot. Cheap, but not stable. I screwed it into the wall studs, but, when hand sanding, the table (to which the vise is attached) still wobbles some, esp. if I get moving fast. I think this wobble is throwing off the flatness of my sanding devices (duh!). I'll get a more stable platform for my vises set up and try again.
 
I wouldnt leave the edge of the spine ultra sharp like a hockey skate. I often take that endge down some so that people can press their hand into the spine comfortably. Your table could be causing it, but its most likely just normal wobbling. I find that more even I am with the height of the blade, the better my lines come out. If i sand from above too much, I apply downward pressure unevenly with my right and left hands, which washes lines out.

Im not even sure how exactly most people hand sand. I use a thin piece of aluminum billet that I wrap in sand paper.
 
Assuming it is wobble that is causing the problems (it probably is), you will get steadier and be able to keep a consistent angle with practice. The same thing happens when using waterstones. After a while your hand gets steadier. Just make sure you practice it the same way every time.

You might try securing the sanding block and moving the knife back and forth, keeping your wrists steady, like you were sharpening on a waterstone.
 
Good point on the secured block. Its sometimes much easier to push the knife against a sanding agent evenly than it is to do the opposite. This is especially true for thinner height blades where the bevel is 1" wide but youre trying to sand it with a much wider block. Its awful easy to rock that block and wash your lines out than if you have the knife in your hand, and can have the whole length of the blade against the sandpaper at once....
 
Actually, I ordered some waterstones last week (hoping, probably in vain, to save money long-term over sandpaper -- can't believe how fast I go through it!). I'll try out the secured block idea. Also, a good point about the block being wider than the bevel -- I made mine much wider so I could get a good draw-knife sort of grip -- I'm going to make some more blocks of smaller widths so I'm not so prone to rock the block.

Thanks, guys.
 
If you are going to use stones, Gesswein or Norton make mold stones. They are what I use. They break down as I use them. This helps keep them from loading up. When they load up they start putting scratches in your work. Lubricate with a light oil will also help. You can use a regular grinder to grind them to the shape you need. A 600 grit stone works great for me. From there you can use sandpaper in 1000 and 1500 grit.
 
I did order Norton stones (I figured their belts are great, so...)

I ordered 220 (to deal with my grinding problems -- still new with my KMG, but not so bad I need to get out the bastard file), 1000, 4000 and 8000. Figured the 1000 and 4000 for polishing and the 4000 and 8000 for sharpening. Do you think I'd be better sticking to micron paper for 1000 and up? I haven't used stones before -- wished I'd asked about them here before I ordered -- they're expensive.

I also got some plate glass and micron paper to re-flatten the stones as required. I think I'll try this out on the flats of the blades too, using the "secured block" idea.
 
Norton water stones are very good. I use them for sharpening my kitchen knives (and those of everyone else I know).

I don't know how they will work for grinding soft steel, if that is what you are planning to use them for. I have wanted to try that, though.

I'm not sure what you mean by using the 1000 and 4000 for polishing and the 4000 and 8000 for sharpening. Typically, you would sharpen a dull knife by starting at the 1000, then move on to the 4000, and finally end with the 8000 (which gives an extremely sharp edge, and usually gives a mirror finish, depending on the steel). The 220 is used to set a bevel, and/or to remove chips.

I can't compare them to micron paper, as I have never used that before. But I have used my stones to polish the flat areas of my knives before, and to smooth some sharp spine edges. They have worked well.

You will definitely want to practice using those stones. The main thing to learn is to keep the knife steady. It won't take too much time to get the hang of it, but it takes time before you can do it reasonably well (I can get a shaving-sharp blade, but it could be even sharper... I'm still practicing...). If you want to get good at using them, I highly recommend sharpening all of your knives, and anyone else's knives you can find!

If you need any help with the stones, I'm happy to offer what I can. (I'm no expert, but I have been using them for a while now.)

Oh, and I'm not sure what you mean by micron paper, but it sounds like you mean very fine sandpaper. Make sure you aren't trying to flatten the stones with sandpaper that is finer than the stone... you will get frustrated... :)
 
Thanks, brash.

I hope to use the 1000 and 4000 on the flats when I want a fine finish, instead of sandpaper (which is called micron polishing paper in the stores around here). Good tip about sharpening all my knives first, to get practice. That will make my wife very happy -- she's been after me about the kitchen knives.
 
What grit belt are you going to on the grinder? If hand sanding is washing out the lines (and it certainly can, believe me I have been there) perhaps the finer you take it on the grinder the less oportunity there will be with the sanding blocks. 400X belts are readily available and can cut some pretty clean lines. I personally go to 600X but those belts are harder to find and have some quirks at that level and weight (I used to go to 800X until they quite making them).

Another thing you may want to try is to always sand the different bevels in different directions, i.e. the scratches on the flat 90 degrees to the scratches on the bevels, this helps you see how level your hand is staying (and angular strokes always keep me more accurate than straight side to side or up and down). Then on the final grit pull them all the same direction.
 
Thank, Kevin. I go to 600x, but I'm still not that steady with the grinder, so I have more sanding to do than I would like.

The different bevels in different directions is a great idea -- I'll try that.
I spent some time this morning stabilizing my workbench, and getting rigged up with a knife clamp and support that should hold things much steadier. I'll see how it works on my next knife.
 
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