Sharpening query with a twist?

[Ogri the trog]

Well a curve at least,
I'm trying to improvise and make a few curved spoon knives. My query is about the outside profile of the blade shape. After a few trial goes, I think I need to curve the outer edge (bevel to spine) to a similar radius to the bend of the blade.
I know that once I get the right shape, I'll be able to sharpen with some wet & dry on a dowel, but is there anything else I need to know about sharpening curved blades?

Certainly hoping to see some replies from the carving guru's.

Thanks

Ogri the trog

 

[Longstrider]

I don't quite undrstand the problem here Ogri. (Maybe I'm not alone and this is why I'm the first to reply)

If you're making the blades from scratch, you need to grind in the bevels prior to bending the thing into the required curve, THEN heat treat. Sharpening should then be a relatively simple matter with some dowel (or a nice straight piece of hazel) and some wet-n-dry.
I even made a strop for mine by wrapping a little off-cut of leather around a piece of hazel, and it finishes up the edge a treat.

 

[Ogri the trog]

Thanks LS,
I'm not sure how to describe my percieved problem - I'm wondering if the outside curve of a hook/spoon knife (both along the axis of the blade and across the width of it) should match the inner curvature of the hollow which it will carve. Some blades I've seen have a flat outer edge but I keep thinking that would only hack lumps out of the hollow rather than carve and leave a smooth finish.
Imagine if you cut a sliver outi of a hollow steel ball, mounted it on a handle and sharpened the inner edge, it would be curved in two planes, along the blade and across it. Or is it sufficient to cut a sliver from a piece of pipe which is only curved in one plane?

Just looking for inspiration to improve my blades.

Cheers

Ogri the trog

 

[Dave Budd]

I'm confused too now

I think you are asking if hook knives with a straight section are able to cut hollows without slicing the front off your bowl? if so, then yes. The straightish bit helps to carve the flat portion of a wide-mouthed or flat based spoon. The hollow is done with the curved end. I mostly make ? shaped hooks and the small diameter ones are best for small forms but the larger diameter ones are more efficient on larger ones.

am I close?

 

[spamel]

I get what you mean! You're asking if the blade should be curved from edge to spine instead of flat like on say a mora. I'd say it's not necessary to curve the face of the blade, the bevel means that the face isn't in contact with the wood anyway, so that one curve creating the traditional "?" shape will be fine. As said before, the most reasonable way to make it would be to take a flat piece of metal, put a straight bevel on it, heat it and bend it round a form to get the required shape and then heat treat it.

 

[Jared]

You mean curved like a gouge, sharpened edge, then curved for the hook?

 

[spamel]

I think he means curved around the normal way and then curved top to botto aswell, like the outside of a doughnut!

 

[Ogri the trog]

like the outside of a doughnut!

Cheeres Spam,
Thats the analogy that I've been missing.
But I must admit to being confused myself now - if the outside edge is flat apart from the bevel..... and the traditional advice is to sharpen the inside curve only...... what happens when there is no more bevel on the outside???????

I'll wait till the summer moot and cop a gander at someone elses tools.....

ATB

Ogri the trog

 

[Longstrider]

Aha ! *small dim lightbulb begins to glimmer in the dark recesses of my long forgotten, and oft unused brain*

I can't see that the blade would need to be curved in the second plane as well as bent into a hook shape. As long as it's not too wide you'll be able to get it in, and around the bowl of a spoon, ladle, or kuksa without difficulty.

I've seen them made with the bevel on either side, and have used them with bevels on both the inside of the hook and on the outside of the hook, and have been able to get along with either type.

I think that trying to make them with a curve between edge and spine as well as between tip and ricasso would simply be making more hassle for yourself than it proved to worth in the end result. Things curved one way don't like to bend the other way too. You might be able to forge a blade that was curved both ways or jerry-rig a pipe bending tool to do the job, but I don't think it would be a worthwhile effort. I like the 'lateral thinking' of your idea though