?Reprofiling and sharpening a convex edge?

S

SOUTHSTAR

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Jul 1, 2009
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I am trying to learn how to sharpen and also reprofile my knives. They are mostly high carbon 1095 and similar steels. The more I research it the more I get confused.
My questions are:

- Im on a budget so I only want to get one system if I can for now. What would be the one do it all system you would reccomend( profiing, sharpening and touching up) my goal is a convex edge as this seems to be the best all around favorite.


-What knife would you recomend for practice? Again similar steel to 1095 .Something really cheap but at least decent enough to want to keep after I'm done should it come out ok.

- Lastly how would one Maintain a convex edge on and extended backpacking trip. It would need to be something small and light to carry around ( possibly fit in sheath pocket).

Thank you for reading my questions . I really apreciate the info and experience you share.
 
For convexing there is really no system its more of a freehand thing. A mouse pad and sandpaper is most common or if you feel like spending slightly more JRE makes a very nice product http://www.jreindustries.com/EMS.htm

To maintain in the field a piece of 800 or 1000 grit paper and one of these would work very well http://www.jreindustries.com/fieldstrop.htm

Some also make their own out of a altoids tin.
 
SOUTHSTAR said:
I am trying to learn how to sharpen and also reprofile my knives. They are mostly high carbon 1095 and similar steels. The more I research it the more I get confused.
My questions are:

- Im on a budget so I only want to get one system if I can for now. What would be the one do it all system you would reccomend( profiing, sharpening and touching up) my goal is a convex edge as this seems to be the best all around favorite. I use a belt sander to sharpen almost everything anymore. you can get the whole setup for around $150 nice shiny convex edges. Read all about it here: http://www.bladeforums.com/forums/showpost.php?p=4916570&postcount=78

If this is out of your budget Knives Ship Free have some great videos on how to manually convex and some great sharpening systems for it also.Check them out here: http://www.knivesshipfree.com/Knife-Care

Another option are the paper wheels Richard J talks about on here. Another great powered sharpening system you can read about here: http://www.bladeforums.com/forums/showthread.php?t=578787


-What knife would you recomend for practice? Again similar steel to 1095 .Something really cheap but at least decent enough to want to keep after I'm done should it come out ok. Moras can be had pretty cheap easy to sharpen and nice blades once you are finished. Old Hickory makes a pretty decent cheap kitchen knife that should work just fine ( I actually learned on some 1.00 Flea Market specials. They all still are around here some where for jobs that i don't want to use a good knife for but still require something with an edge.

- Lastly how would one Maintain a convex edge on and extended backpacking trip. It would need to be something small and light to carry around ( possibly fit in sheath pocket). To just maintain the edge a couple of loaded strops glued to either side of a paint stirrer should work or KSF and JRE make something specially for this

Thank you for reading my questions . I really apreciate the info and experience you share.
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I hope this helps Good luck.
 
There is no particular cutting advantage to a convex edge, unless it's on a chopping instrument. Any edge done by hand will be somewhat convex, anyway.
A fine mill bastard file, and a fine India stone (or Arkansas stone) will be all you need. Strop the blade on cardboard.
 
Bill DeShivs said:
There is no particular cutting advantage to a convex edge, unless it's on a chopping instrument. Any edge done by hand will be somewhat convex, anyway.
A fine mill bastard file, and a fine India stone (or Arkansas stone) will be all you need. Strop the blade on cardboard.
Click to expand...


And where did you get this info from?
 
Bill DeShivs said:
There is no particular cutting advantage to a convex edge, unless it's on a chopping instrument. Any edge done by hand will be somewhat convex, anyway.
A fine mill bastard file, and a fine India stone (or Arkansas stone) will be all you need. Strop the blade on cardboard.
Click to expand...

The only advantage I have found on a small (folding) blade with a convex edge is the ease of sharpening with a belt sander ( I hate to sharpen knives) once I get them convexed with the sander I usually just maintain them with a couple of charged strops (black and green ). This has worked really well for me but there is no real advantage to the convex edge vs the "normal" style edge in how they cut just in allowing me to be lazy.
 
Bill DeShivs said:
40 years of sharpening and using knives, making knives, restoring knives, designing knives, and collecting knives. Is there something I'm missing?
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Proven geometry.

Its a fact that a convex edge will have less resistance in cutting because less surface area of the edge is making contact = less friction.
 
I have never known friction to be a problem when cutting with a sharp knife! The apex of the edge does the cutting. It doesn't matter how you get there, as long as it's sharp.
Since people discovered that sharpening on a soft surface evens up their imprecise attempts at hand sharpening "convexing" has been all the rage!
 
Mr Deshivs is the man, but i do like my mouse pad. I would say useing a dia-fold like a file would be my choice for field sharpening.
 
There is nothing wrong with using a padded surface, but there is no great advantage to it, either. It is easier for a novice to get a decent edge using a padded surface.
 
I love the look of a good wide convex primary grind, but have not found a difference in cutting when using one. That said, most of my knives have conves edges put on with a belt sander and touched up with a Sharpmaker between full sharpenings. I've been meaning to get a sandpaper and mouse pad setup, but havent had the need. I'm mostly interested in the very sharp, yet toothy edges I've seen from people using 600 grit wet dry as the final sharpening grit.
 
Anks for the advice. I think I know what I'm going to try now.

I should have mentioned that I already tried the mousepad sandpaper deal and found that the sandpaper start to get very expensive because the higher grits don't last 2 min
I may just pull the trigger on a cheap beltsander from harbor freight. Then use a strop for touch up. Thank you guys.
 
SOUTHSTAR said:
Anks for the advice. I think I know what I'm going to try now.

I should have mentioned that I already tried the mousepad sandpaper deal and found that the sandpaper start to get very expensive because the higher grits don't last 2 min
I may just pull the trigger on a cheap beltsander from harbor freight. Then use a strop for touch up. Thank you guys.
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Your wet-dry can be cleaned and used for some time, even when it wears down its still usefull.
 
SOUTHSTAR said:
Anks for the advice. I think I know what I'm going to try now.

I should have mentioned that I already tried the mousepad sandpaper deal and found that the sandpaper start to get very expensive because the higher grits don't last 2 min
I may just pull the trigger on a cheap beltsander from harbor freight. Then use a strop for touch up. Thank you guys.
Click to expand...
With sandpaper in 2000grit+, the abrasive will fracture and get smaller and smoother, just use a pencil eraser to rub off the metal and it's pretty much reusable.
 
knifenut1013 said:
Proven geometry.

Its a fact that a convex edge will have less resistance in cutting because less surface area of the edge is making contact = less friction.
Click to expand...

I have seen no evidence of that in my 65 years on this planet. :D

I agree completelty with Bill Deshivs. Convex may have a slight advantage for chopping, but none for cutting.

Now I have a belt sander, and I do convex big outdoor knives and axes, but my "cutting" knives are all "V" bevelled on an Edge-Pro.
 
Ben Dover said:
I have seen no evidence of that in my 65 years on this planet. :D

I agree completelty with Bill Deshivs. Convex may have a slight advantage for chopping, but none for cutting.

Now I have a belt sander, and I do convex big outdoor knives and axes, but my "cutting" knives are all "V" bevelled on an Edge-Pro.
Click to expand...
IMO a convex edge works a bit like a reprofiled edge with a microbevel.
 
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