Flat Grinding a Recurve?

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OTK

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Feb 10, 2010
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I've been wanting to try a few recurves with a flat grind. Can you guys offer some tips?

Thinking about it, I keep thinking it will be tricky to get the edge thickness of the concave section the same as the rest of the blade. How is this done?

Thanks!
 
i grind them on the corner of my platen (belt slightly over the edge) but it sure is tricky

and by that i mean keeping things from getting uneven when using such a small part of the grinder
 
I find that setting the angle of the grind in where the blade turns up to the tip helps. I end up dividing the grind on either side up into 3 sections.

Wayne
 
I just simply try to keep the cutting edge perpendicular to the belt.

it requires a bit of an S curve movement with your arms and it's weird to describe but it works just fine

DON'T STOP MOVING THE BLADE. if you pause for a moment you will get a bad divot.
 
Thanks for the tips!

Stephan, are you using the whole platen or the edge? Seems like the edges would dig in when the apex is in the middle of the platen?
 
blackcatt said:
Thanks for the tips!

Stephan, are you using the whole platen or the edge? Seems like the edges would dig in when the apex is in the middle of the platen?
Click to expand...

I use the whole platen, thus the comment about never letting the blade stop moving because really technically I'm using the edges of the platen.

it took me some practice but I got good at it. I do a LOT of recurves (I like em)
 
Thanks! I am starting to like them too. Your work is really tasteful and well executed Stephan. I'll give a few of these techniques a try.
 
Not sure what kind of equipment you are using, but here's what I did.

I know this is not conventional, but you might think about running the concave part of the bevel parallel to the belt. In other words, use the wheel itself as a flat guide. If you do a really, really high saber grind (say 1/4 to 1/8 inch from the spine) you can grind the excess off and still be happy.

Just a thought.
 
How about grinding with a narrower belt.... like a 1"? I would think the narrow belt would conform to the re-curve contour tighter than a 2" belt.
 
I have only one example, the top knife in the pic.

It was quite challenging but fun and I learned a lot. I set the plunge by hand with files, then ground the bulk of the bevel more or less parallel to the belt, using the bottom (drive) wheel on my grinder as a contact wheel, getting to about 80% finished, maybe a bit more. Then I draw filed to get everything "flat" and even. Lots of draw-filing. Marker or layout dye will really make the low spots stand out. Then I sanded with 220 paper to get the file marks out.

I find it quite tricky, but rewarding. Don't try to grind as aggressively as you would a regular profile. Go slow and in smooth passes. I strongly recommend trying it out on a piece of scrap steel or wood before commiting to quality cutlery steel.
 

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I like using the Spyderco Tri-Angle Knife Sharpener (STAKS), and so does everyone I get one for. I used stones for decades fairly well, as did my old man. If you're content with either a 30 or 40 degree bevel, the STAKS makes reprofiling and getting razor sharp edges (ready for strop) easy--if you're patient. Regarding your question, the triangular cross-section of the rods makes the shape of the blade (e.g., recurves) irrelevant. It's even easy to sharpen serrated edges. Just make sure you get the additional diamond rods to speed the sharpening process (I think they're indispensable and use the medium and fine rods that come with the kit to mainly finish the edge).
 
I've only done one. I did it in a similar fashion mentioned above. I used the wheel of the grinder. Using the wheel where the grit it stretched open really chews out the steel though. Nasty scratches to sand out if your finest belt is a 120 like mine was -_-
 
here is a pic of the folder i made the other week its abut 3 inch of blade and while not recurved it is a hawk
dsc06623sm.jpg
 
Folders look sick Butch!

I'm gonna hit the shop and fool with these recurves tonight. Thanks for all the tips!
 
I have done one recurve and muck like James did I rough ground it in using the edge of the platen and a s like motion to keep the edge square to the belt. I then went bak and draw filed everything till I had it looking like I wanted.
 
Just to clarify, I did not use the edge of my platen like others did... I found it way too difficult to keep my grinds smooth on the scrap piece I tried first. (I do often use the edge of the platen on regular flat grinds)

I used my contact wheel with much better success and far fewer gouges. Still took a lot of draw-filing to get it right, though.

If you are ever in doubt, regardless of grind style, do less work on the grinder and more with files. If nothing else, draw-filing will quickly show you where the uneven spots are so you can go back to the grinder and clean them out.
BillWolfel said:
I like using the Spyderco Tri-Angle Knife Sharpener...
Click to expand...

I have no doubt that's a nice sharpening system, but I would rather chew off my own hand than grind a whole blade with one. Welcome to ShopTalk... it's generally more productive to actually read the OP's entire question, and perhaps even the rest of the thread, before posting. ;)
 
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How did I miss that Tutorial Phillip? Very cool, I have only done a few recurves so I will be practicing as well.
 
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