Fredeen Blades

i was wondering about different types of grinds and how you maintain knives without a secondary bevel (by secondary bevel i'm talking about the small bevel that makes the edge). Specifically I'm thinking a using a scandi grind on one of my knives and i want either a hand rubbed finish or a mirror finish on the flats and a rubbed finish on the bevel. I know my sander wont do a nice enough job. Will i be able to get the finish i want with stones?

can you get stones that are a high enough grit to polish? I thought i read somewhere that  japanese knives and swords were finished entirely with stones?

jason

Hey Jason,

Firstly welcome to my website, glad to have you.

As far as blades with zero edges (no secondary edge bevel), eventually with use and re-sharpening, the zero edge will actually go away and secondary bevels will form. As far as "maintaince" goes at least. Unless you regrind/sand the whole primary bevel every time you sharpen.

As far as finishes go, you have a few different options, some will be easier than others. As far as stones go, yes you can achieve extremely great finishes with stones. Traditional katanas are polished out completly by hand with water stones. However it takes many many more hours than you would ever want to do, to get a fine mirror finish. Additionally the stones necessary to do this will cost you an arm and a leg.

Another problem with stones is that they are great at doing flat things, but when it comes to curved surfaces, not so much (unless you specially shape stones to fit each and every blade you do).

Hence, the best option, in my opinion is some good old fashioned sand paper. You can make some wood blocks that have a bit of curve to them to roughly match the curve of your bevel, and glue a bit of leather on them for some backing. By using this, you should be able to achieve a really nice hand rubbed finish, and if you wanted to take it that far, buff to a mirror finish afterwards.

Basically here are the steps I would take to do a nice hand rubbed finish on a blade:

1. Use the grinder to put as fin of a finish on the blade that it can (say 800-1000 grit) as this will cut down on your sanding time.

2. Going in the opposite direction of the scratches from the grinder, step down to 500 grit and go along the length of the blade until you get all the grinder scratches out. If you are doing a scandi grind, sand the convex portion of the blade first, and then do the flats, otherwise you can wash out the flats a bit (you can fix that though, so I guess it doesn't make too much of a difference). You can sand back and forth on the blade to get rid of the pesky scratches, but once they are gone, you'll want to sand in one direction, starting at the ricasso/tang shoulders and pulling to the tip, in one smooth fluid motion. You'll need to do this at least 50 strokes, constantly replacing the sand paper as it wears, so you get really nice clean cuts with each stroke.

For most hand rubbed finishes, 500 grit is pretty nice, however, if you want to take things further (especially if you want to mirror polish) you have some work cut out for you.

Step up the grit to about 600, and sand going 90 degrees to the last grit. Again, sand until you have all the previous scratches out.

Step up the grit to 800, turn 90 degrees, sand until no more scratches going the other way,

And repeat this for 1000 grit, 1200 grit, 1500 grit, and on up to at least 2000 grit for mirror finishes. On your last sanding, make sure you go along the length of the blade, and again, single direction strokes.

You don't have to follow the grit jumps exactly, however, jumping too far means hours of sanding to try to get out the previous scratches, and possibly having to go back down to a slightly more agressive grit to get them out anyway. So the smaller the grit jumps, the easier it is to get out the previous grit, but more grit sanding steps to do in the first place.

For a mirror polish (and I mean true mirror, not the "mirror finish" where you can still see faint scratches), after you are up to at least 2000 grit, you'll need to go to a buffer and start buffing. The buffer is one of the most dangerous machines in the shop, it will grab blades from you, cutting you hand, and then throw the blades across the shop, into the ceiling, into the floor, or in the worst case, into you, so be careful, and concentrate, the slightest distraction or wandering thought can cause you to tip the blade just enough for the wheel to grab it. You'll need to start with some more agressive compound, I start with green chrome. Buff up to the bevel transition line (not over, or you'll wash it out) from each side. Once the blade is buffed nicely with the green (should look pretty close to mirror), switch wheels to some white jewelers and repeat, and finally to finish it off, use some pink scratchless compound.

True mirror finishes are excessivly labor intensive, and really best left to display and collectors pieces, as the faintiest piece of dust or dirt will put in fine scratches and will ruin all your hard work.

Hope that makes sense, and don't hesitate with any other questions.

Graham

Ok that explains a lot thank you. I was trying to get a question across but I’mhaving a real hard time explaining it. I’ll give it another try.

When I make a double beveled knife, after heat treating I do the finish grinding and sanding, put the knife together and finally once together I rip the edge/secondary bevel on my sander. At this point the knife is sharp but the edge is not refined (it’s still jagged like serrations). I then take it to my oil stones and follow this by stropping on leather.

My question is, with a single bevel knife after the heat treatment I would finish the grinding on my sander this will allow each bevel to meet and create my edge. Problem is my edge will still be jagged and not refined. I don'treally know what to do from here with this type of knife???

Do I bring it to my oil stone and strop like a normal double bevelknife? If I do then won’t the oil stones and stropping dictated the finish of the bevel/edge. I'm assuming you can't hand sand it after sharpening on the stones or you will dull the edge (if you dull it you will have to go back with the stone then try to sand again, then you'll dull and need the stone once more thus creating a vicious circle of knife death!!!)

My finest grit oil stone does an ok job on a small secondary bevel but I can't see it looking good on a single bevel blade where the bevel is 1/3 the width of the blade. Thats why I asked about other finer grit polishing stonethat could polish and sharpen my edge (or not dull my edge if you want to lookat it like that) at the same time.

I have no idea if you’re going to understand this

Thanks for taking the time graham, it is really appreciated!!!

Jason

In the case of a knife with a zero edge, your hand sanding/hand finishing can actually put a pretty decent edge on the blade, followed by a light touch up on stones and/or stroping (but at a slightly steeper angle so only the edge is brought in contact, not the entire bevel of the blade).

The hand finishing process and bringing the bevel down to a zero edge will make things pretty darn sharp, you might be supprised (just be careful when hand rubbing a blade like this, as you are bound to slice yourself open pretty good). The japanese katana is actually sharpened in the polishing process and has a zero edge. If you used very fine stones (3000 grit and up) and had a flat grind, you could both sharpen and polish a blade (in the same process) with a true zero edge. However, the vast majority of knives with "zero edges" actually don't have true zero edges.

The easiest way to think about it is when you put on your final edge on the blade, even with a zero edge, you will essentially be introducing a very very small secondary edge that is at just a slightly greater angle. Since the blade will essentially be sharp when it comes out of the hand finishing state (or even grinder state), the faint secondary bevel you introduce is just more to remove the wire edge (burr) and polish the edge a bit. In fact a strope (or quick light buff on a buffing wheel) may be all thats necessary (this process actually rolls the edge as well as polishes it).

Don't get too caught up with zero edges and this and that and trying to keep a true zero edge. In many cases zero edges are too acute and don't have enough meat behind them to truly support such a fine edge in use, so they are not always the most desirable thing in the world. They can put excessivly sharp edges on things, but they should only be implimented when the actual function and purpose of a blade dictates.

ok that was exactly the info i was looking for thank you much!

jason

Sure, no problem. Glad to help.