edge dulls quick - whats the solution?

DavidL41 said:
Ok so let me try to understand. I should get a more aggressive type stone for this sort of steel like a norton or dmt and the type of steel I have or stainless in general is harder to sharpen but holds a slightly longer edge. This steel doesnt handle green compound/ chromium oxide because the steel doesnt sharpen well with it and rounds the edge as a result?

Can I keep stropping the blade on a carbon knife once I set the knife up or will it eventually round the edge?

If I was to buy a brand new knife in the future for leather working a white carbon steel blade thats has a thin edge like 30 deg inclusive would hold an edge for a long while before it needs to be re sharpened? Are there any benefits of going as low as 16 degree inclusive for leather working.There isn't too much stress on the knife and will be handling stretchy type leathers that needs the sharpest edge or else it will stretch it out.

Basically the above is my idea of what the best knife Is for my task, however I'm not that savvy and have as much knowledge on this matter.

In your opinion since the knife I have isn't as good as I thought it is, what specs would make the best knife for my application for PRECISION, SHARPNESS with the use of a ruler. This would really help me out.

1. blade length
2. type of carbon steel
3. Blade angle
4. type of grind (Scandi, hollow,convex ect) opinion on chisel grind vs double grind?
5. blade shape
6. Some one who makes this sort of knife or one thats in production.
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It isn't that the 154cm can't be made very nice with the CrO (is one of my favorite blades steels), is more that you should move to a finer stone before stropping with an abrasive that fine. Coming off the fine side of the hardware stone (and this might very well be all the stone refinement you need for your application - I'd think a finer edge would be a benefit - only T&A can say for sure). But a larger stropping abrasive will make a better matchup for the level of refinement from the current stone, and it can do a lot more repair work - CrO is for a final touch-up, not repair.

Stropping any blade steel can and will round the edge over time unless you move to a very hard backed strop. The real question is whether the blade geometry can hold up, plenty of wood carvers maintain their tools with strops for extended periods and have no complaints. A low angle, thin stock, and a blade grind that is shallow might be a big step up.

The inclusive angle is important, but the overall blade stock is more so and should be thin, like a kitchen knife. Digging into a wood backer I'd imagine a Wharncliff pattern or other with a somewhat squared off tip (that is expendable) would be preferable to something with lots of belly. A short blade will give far more leverage, and a fairly fat handle will distribute the forces to your hand better. If you're following patterns with tight curvature, the overall blade should be fairly small so it can turn in a smaller radius. Is possible some of the existing wood carving knives might be a very good fit, or even a standard utility knife with some extra work done to the edge. The steel type is a distant secondary concern IMHO to the overall grind and pattern in this application.
 
Echoing what Martin said^^ about overall blade grind/thinness (good advice), if I were to choose my 'favorite' blade for cutting leather, it'd likely be one of my stockman pattern knives in a simpler steel like 1095 (my Schrade 8OT) or CV (Case '75 pattern). In both examples, I've noticed the THIN grind of the sheepsfoot blades to be awesome leather-cutters (a thin spey blade can also work well), among other tasks like opening boxes and plastic clamshell packages. As Martin said, the overall thinness of the grind, and secondarily a more acute edge angle, can make the biggest difference. The other upside to using steels like 1095 or CV is, they're very easy to maintain almost entirely on a well-configured strop, firmly backed underneath a substrate like denim or linen, with either or both of aluminum oxide compound (white rouge or a grey compound, for 'edge repair', as he mentioned) or green CrO for fine-tuning the finish. They might need or want more touching up in use, but the combination of thin grind, relatively low edge angle and simple steel make maintenance almost effortless, as opposed to trying to fine-tune a thicker blade in more wear-resistant steel.

As he also mentioned, green compound won't do a whole lot for 154CM at a coarser edge finish, due both to it's small grit size and relatively lower hardness than something like AlOx or SiC (or diamond) compounds, which can do a lot more for 154CM at a given grit size. Green compound works noticeably better on simpler steels as mentioned above, as well as with low-alloy stainless like 420HC.

Might also consider using a different backer board underneath the leather when cutting. If the particular wood is contributing some abrasive wear, a different material might lessen that. Maybe a poly cutting board, or hobby/craft shops also carry 'cutting mats' made for such things, which presumably are easier on cutting edges (of Xacto knives and similar hobby-type blades).


David
 
A friend of mine is a holster maker and he once told me that for the same reason (dull blades) he switched from wood cutting surface to rubber matt. The kind used in horse stalls about 2x2 size. I beleive that he uses disposable blades. I recently made a Kiridashi fron 1/8 stock and it works wonderfull for cutting leather with precission. Hope this helps.
 
I'm fairly new here but I've cut a lot of leather and I also cook a lot. I recommend you get a $7 Old Hickory brand paring knife and a two or three blade carbon steel pocket knife (from a quality supplier) learn to sharpen on them. Also use them on scrap leather and fresh tomatoes. Learn to get them sharp enough to slice tomatoes paper thin. I started on decent stainless and thought I understood sharpening well but when I learned to sharpen carbon steel I developed better edges, and this carried over to my more expensive stainless knives. Also you can easily change the angle on a CS blade to see what a different angle might do for you.
 
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