Drawknife/shave Sharpening

Ted Calver

Moderator
Staff member
Messages
6,761
Location
Yorktown, Virginia
A neighbor gifted me with a draw shave similar to this one. It shows very little use and the rust on the bevel buffed off easily. The bevel is hollow ground and the steel appears hardened (file skates), but it looks like someone has filed a bevel on the back of the blade. I was always under the impression that these were sharpened like chisels or plane blades, and for that to be effective the back needed to be flat. Anybody with any experience sharpening these kinds of shaves care to offer an opinion on whether I should attempt to flatten the back?
IMG_1484.jpg,IMG_1483.jpg
 

Ryan Mooney

Moderator
Staff member
Messages
6,085
Location
The Gorge Area, Oregon
I'd try it first and see how it cuts with the current profile. A small back bevel reduces it's desire to dive somewhat so it might be intentional if it was too grabby. But also increases the included bevel do it's less "sharp" than it would be otherwise. So a bit too the one side a little too the other.. Doesn't look like it's a huge bevel anyway so if you decide to reduce it shouldn't be too bad.
 

Ted Calver

Moderator
Staff member
Messages
6,761
Location
Yorktown, Virginia
Thanks, Ryan. Curtis confirms my thoughts on sharpening the back. I only have one other shave, a straight knife, made in the USA Craftsman that was one of my first tool purchases. Didn't realize there were bevel up and bevel down styles. He sharpens flat backs on both styles and says that, while many people put a back bevel on the bevel up tools, he likes a flat back with the edge honed from the back to roll the edge slightly for a back bevel. That probably explains the back bevel on this tool. The curve on this tool makes it hard to do any serious stone work or even grinder work on the back side. Maybe I'll see if I can get in there with something on my angle grinder to flatten or hollow grind the back like Curtis did. Shouldn't be too hard.
 

Ted Calver

Moderator
Staff member
Messages
6,761
Location
Yorktown, Virginia
Thanks, Brian. That's the ticket! What the heck is the difference between my curved shave and a "scorp", the amount of curve? When I got it I thought it was a scorp.
 

Ryan Mooney

Moderator
Staff member
Messages
6,085
Location
The Gorge Area, Oregon
Using a spindle sander (not oscillating, drill press or no) would work pretty well as the Curtis video notes. The other option would be some 100 grit wet/dry around a 1-2" dowel, I suspect that would go quicker than you'd think. I'm mostly of the slower is better on this sort of thing, tends to make less to do to fix the thing after :D

The one thing I think you'll have a bit of a problem with on this one is that it's so thick that pulling the heel off of the bevel edge might take a fair bit of effort. I have some modern draw knives with a similar issue that I actually did basically a double grind on and essentially ground a pretty big secondary bevel behind the primary bevel so I'd have less material to deal with there. If I had a decent 1x30 belt sander I think I'd have ground them down 1/8" or so all over.
 

Ted Calver

Moderator
Staff member
Messages
6,761
Location
Yorktown, Virginia
... If I had a decent 1x30 belt sander ...
Hmmmm...another tool I'd like to have. The fancy knife sanding rigs $$$ on Forged in Fire look pretty versatile. I saw a decent looking Grizzly on another forum in the $500 range. The fancy knife rigs are pricey, but if you can weld there are plans for making your own. A 1 x 30 would be handy though.
 

Ryan Mooney

Moderator
Staff member
Messages
6,085
Location
The Gorge Area, Oregon
I have some rollers I got for the good price of free that I think would work for the back rollers, I'd need another larger one for the front. A metal lathe would be super handy for making parts :D. You don't actually need to do a lot of welding either, I've seen a few that were basically just bolt together (at least for the most part, plus a few cut & grind parts from chunks of angle iron, etc.).
 

Frank Fusco

Member
Messages
12,226
Location
Mountain Home, Arkansas
I have attempted sharpening my draw knives only a few time. Real task as I recall. I used a hand held stone and no back side bevel. Once sharp that do not need resharpening often if the wood is clean.
 

Don Baer

Moderator
Staff member
great information.... not to high jack the thread but I remember while taking a class with Sam Maloof someone asked him why he didn't use a draw knife or a spoke shave to shape his chairs.... he went to his cabinet and got one out and took a few passes on the piece he was working on laid it down and said..."way to slow" . then he picked up a router in one hand and the piece in the other and proceeded to shape the piece... later he said that "there is no right or wrong tool to use, use the one that you are comfortable with and gets the job done."
 

Ted Calver

Moderator
Staff member
Messages
6,761
Location
Yorktown, Virginia
No hijack, Don. I'm envious you had a chance to take a class from Sam, and totally agree with his sentiment about the draw knife being slow. The last time I carved a chair seat I used one of those big carbide porcupine wheels on a grinder. It was an absolutely fantastic way to sculpt and because it was so fast I didn't get bored with the process.
 
Top