Upkeep of a convex edge?

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Nikokurausu

Joined
Jun 19, 2006
Messages
539
So, most of the knives and own and am interested in owning come with convex edges. I currently only have a Sharpmaker that I use to keep my blades sharp but I don't want to lose the convex edge I have on most of my knives. So I'd like some suggestions.

I know many use a strop with some type of paste rubbed in to it and that's the most attractive option to me since it seems as though you burn through a lot of sandpaper using the Mousepad & Sandpaper method. Hand American looks good for strops but what pastes should I look for?

Another way I've read is to use some of the same paste on an absorbent material atop a hard backing. How well has this worked out for you that have done it?

I'd also like to hear any other suggestions you can think of that you would like to share.

Thanks,
Nick
 
You can also use a piece of cardboard as a strop, with or without any compound. You can also use your fine Sharpmaker hones in the base as a flat stone and follow the curv of the convex. The second method is easier on a full convex blade and large convex bevels.
 
Nikokurausu said:
I currently only have a Sharpmaker that I use to keep my blades sharp but I don't want to lose the convex edge I have on most of my knives.
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Most convex edges are sharpened with benchstones, you just roll the blade to match the curvature. You can use the Sharpmaker to do that readily if for some reason the aesthetics of a smooth arc appeal to you.

-Cliff
 
So what exactly should I be looking for in terms of feel? I've attempted that with the Sharpmaker a few times already but the results have been so-so. I don't want to end up rolling too much and smoothing the edge.

Also, how would I restore a convex edge if I use the Sharpmaker to thin the edge? I'd like to do that on my Swamp Rat M6.
 
If you already have a convexed edge, you will not burn through much sandpaper at all on the mousepad. If you are reprofiling that way, then yes.
 
Nikokurausu said:
I don't want to end up rolling too much and smoothing the edge.
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It is not easy to go by feel initially, I would forget about that for now. I would also forget about the fact the edge is convex as well. Concentrate on sharpening at a sensible angle as that is what controls the majority of the performance, the curvature is a DISTANT second.

Also, how would I restore a convex edge if I use the Sharpmaker to thin the edge? I'd like to do that on my Swamp Rat M6.
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Generally trying to reduce the angle on the Sharpmaker is a really time consuming process and I would strongly recommend an x-coarse benchstone. What I do in such a case is roughly the following :

1) Set the main edge bevel at a decent angle with a x-coarse stone. This is done freehand and is usually flat with a very light curvature, maybe 1-2 degrees at most due to wear in the stone. I use naturals or loose bond waterstones to do this so they will tend to scallop readily. If I do it with diamond/ceramic plates the edge will end up pretty much near flat with no measureable curvature.

2) Set the very edge at a suitable microbevel. The thickness of the edge depends on the type of the knife. For large choppers the micro-bevel isn't really micro as it extends up to about 0.015" in thickness. For small cutters however it is not even visible, being about 0.001" thick and is set with just 2-4 passes on the finishing hones.

Now for resharpening, I just work the final bevel for a few sessions until it thickens to the point it becomes time consuming to sharpen at which point I recut the primary again. At no point do I think CONVEX bevel, I am always just thinking about the required angles and thickness. I can guarantee that if you shift you focus to that viewpoint it will both become a lot easier to sharpen and as well the performance of your knives will improve. Most of the blather about convex edges you read is just snake oil.

-Cliff
 
Thanks for the help and ideas gentlemen.

db,

I'm going to give that a try the next time I go to touch up the M6. Thanks.

Cliff,

Thanks for the method. From the reading I've done and the reprofiling of my BM 710D2 on the Sharpmaker, I was guessing that something like a DMT D8XX or D8X would be in my future. Probably some kind of angle guide to get started since I'm still new to this.

Shann,

I'll give the sandpaper a whirl when I go to touch up my Muddy Skeleton Warden.

Once again, thanks all.
 
Nikokurausu said:
.... something like a DMT D8XX or D8X would be in my future. Probably some kind of angle guide to get started since I'm still new to this.
Click to expand...

You don't need the angle guide, that is mainly a cosmetic issue, and DMT's are kind of expensive. I refer silicon carbide waterstones for reshaping and even the oilstones work ok, though you need to press harder. They are much cheaper, start at about 5$.

-Cliff
 
I actually think a DMT would be harder to learn the basics on, as it takes a much finer touch and has much less feel that traditional stones. That said, I think they are great once you know what your doing as they do cut fast and easily. And since they take less strokes and less time its easier to keep a consistant angle. I recently got a fine and extra fine stone, and really like them for all but the heaviest of reprofiling. But yes, they are pricey.
 
I'd just like to say thanks again to everyone for their help. I'm going to start giving the different ideas and methods a whirl and see what I can get out of them.
 
Very informative. I am not a great sharpener and I have a Bark River Mini Canadian (convex) coming in the mail. It never even ocurred to me that I'd have to treat a convex edge differently.:thumbup:
 
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