Sharpening a drawknife.

[undergroundhunter]

Afternoon all,

Having just come back from the Great Yorkshire Show with a new Ray Ils gents drawknife I'm wondering what is the best way to sharpen it. I'm not talking stone types or weather to hold the stone and move the tools or vice versa, I'm asking weather it should be a fully flat bevel, a micro bevel or be a convex bevel. Obviously its just ground at the moment so not razor sharp hence the question. I do have a large drawknife that I bought second hand from eBay which came with a flat bevel so that is how I have continued to sharpen it.

I'm not aiming to start a 30 page thread that ends in an argument I'm just after opinions from people more experienced than me as I'd rather not mess it up.

Matt

 

[AndyT]

I do mine as a single flat bevel. It's the consequence of holding the knife still and moving the stone across and along it - I find it far easier to follow the surface that's already there than try to establish a new one at a different angle.

 

[ED65]

You can do it the way you prefer Matt, rather than there being a way that it should be done. Which probably sums up just about everything in woodworking, if not in life

I'm not aiming to start a 30 page thread that ends in an argument...

From your lips to God's ears!

 

[undergroundhunter]

Magic thanks guys. My large drawknife works beautifully so I will do the small one the same way.

Matt

 

[Jacob]

The shape of the bevel has zero effect on the cutting edge - within reason; too hollow ground would be weak. So just sharpen as best you can with any of the usual methods, aiming at a 30º ish edge.
Mine end up with a slight convex bevel - not because there's any point in it , it's just a by product of my sloppy quick and easy (but effective) sharpening!

 

[Sheffield Tony]

We can't possibly leave this thread with such a straightforward conclusion surely ...

For what it's worth, the drawknife is the one tool I like a single, slightly convex bevel on. Especially the English and American pattern ones which I use bevel down, where I think it gives better control of depth of cut.

On the other hand, my French pattern drawknife is used with the main bevel up, and that one I keep flat. And the French one is by far my favourite. You didn't expect a rational answer did you ?

 

[essexalan]

I was going to ask the same question but decided I would come out more confused than ever so I just cleaned up the flat side and sharpened the bevel at the 25 degrees it was ground at. Only used it so far for trimming green walking stick shanks and it worked fine bevel down, my preference. Of course when the shanks have seasoned a bit more then that bevel may not stand up to working blackthorn and hawthorn. I can only say I like the bevel flat as it is because I have not tried anything else.

 

[woodbrains]

Hello,

Single bevel, always. A drawknife is a bevel controlled tool, a secondary bevel makes control difficult. The bevel should be set to make the tool present to the work at a comfortable attitude. If this bevel is too thin to hold an edge, then thicken with a back bevel.

Mike.

 

[Derek Cohen (Perth Oz)]

There is a sharpening jig designed by Peter Galbert, who is a sensational chair maker, and marketed by Benchcrafted. Here is a link to a video ...

https://www.youtube.com/watch?v=i8AiS9zlRwk

I have the jig but have yet to take it out of the wrapping! I was curious.

What I do is hollow grind the blade, and then just freehand it with stones. It gets really sharp, and is quick to maintain. I follow the guidelines of Curtis Buchanan, an even better chair maker ..

https://www.youtube.com/watch?v=-R8FpLPx4wo

https://www.youtube.com/watch?v=rcjqp6dpkRs

Regards from Perth

Derek

 

[Jacob]

..A drawknife is a bevel controlled tool, ...

In which case a convex bevel is essential. A flat or hollow bevel lets the bevel ride on heel and/or toe but nothing in between.
Same reason that carvers use convex bevels - there's more to it than just ease of sharpening!

 

[Derek Cohen (Perth Oz)]

True - to some extent - Jacob. The back of the blade must not be flat. It benefits from a very slight rounding (ala a rounded back bevel).

I wrote the following in a sharpening article on my website ...

Step 2: flatten the back (sort of ..)
Sharpening a drawknife is no different from sharpening a chisel or a plane blade. It all begins with a flat back to the blade. In actuality one does not want the back to be perfectly flat, but instead have a very, very slight camber. Very slight. I find that this aids in releasing the cut, where a flat back can cause the blade to dig in. Flatten first, and add the slight camber at the end.

Link: http://www.inthewoodshop.com/WoodworkTe ... knife.html

Regards from Perth

Derek

 

[Trafalgar]

Needs a bevel on both sides, like a carving tool, 15* or so but nothing you'd ever attempt to measure.

 

[Jacob]

Basically it doesn't do to think about it too hard. Just sharpen the bloody thing!
If you get a jig like Derek's I'd do as he has done; leave it in the wrappers.
It's obviously a premium daft gadget but you might be able to sell it on!

 

[Trafalgar]

They're not that hard to sharpen but the bevels are a must so you can come out of the cut rather than the tool diving like a submarine through the wood. Some will say to keep the back flat and use the tool bevel down on delicate cuts but I don't think so...

Frustrating for me at first... I was over-analyzing.

 

[D_W]

They're not that hard to sharpen but the bevels are a must so you can come out of the cut rather than the tool diving like a submarine through the wood. Some will say to keep the back flat and use the tool bevel down on delicate cuts but I don't think so...

Frustrating for me at first... I was over-analyzing.

Agree. If it dives and rips a stick apart because the bevel is too gradual (just like carving tools), no fun will be had. No stock will be saved.

It's like the cap iron (in terms of figure out about where it should be by experience and feel). If it dives, widen the bevel. If it skids, thin it.

The sharpening gadget is beyond me.....and I am pretty easy to sell to sometimes.

 

[custard]

Used on long grain a drawknife can stay sharp for ages, I guess it's basically splitting out the waste, so after the initial entry it isn't doing much actual cutting.

Used on end grain it needs regular sharpening to operate efficiently.

Despite that I've never found it worth keeping different drawknives with different bevel angles for different tasks. Even when I was making windsor chairs regularly I just used the same drawknife for everything.

If you find a knot, even a pin knot, I find it really pays to slice through by angling the drawknife and using as much of the cutting edge as possible. If you just slam through you can get a minute ding in that section of the drawknife, it's a pain to sharpen out, but if you don't then it impairs the tool's ability to slice smoothly.

A bit like card scrapers, personally I don't like drawknives that are too hard, I've seen some modern ones that are really hard and that just makes sharpening too problematic. Sooner or later your attention will wander and you'll slam through a knot, when that happens you'll be glad to have the marginally softer steel that you generally find on older drawknives.

I've met really skilful drawknife users who sharpen differently, some with a single bevel face like a cabinet maker's chisel and some with an additional small bevel on the opposite face like a carving chisel. I suspect, but don't know this for a fact, that the guys doing more free hand shaping with slow curves (like boatbuilders) tend to prefer the double bevel; where as the furniture makers and chair makers (doing more straight work with the odd quick curve thrown in for things like stopped chamfers) tend to go for a single bevel.