Stropping large/thick convex edges

[MVF]

Does leather mounted on wood have enough give for stropping a thick convex edge (.25")? I'm thinking along the lines of the Busse FSH. Or would it be better to put a layer of the infamous mouse pad in between?

Also, in reading Durbin's strop thread, mention was made of using an old belt- would the dye cause any problems?

Thank you all for sharing your knowledge:thumbup:

 

[gud4u]

Forget about the color of the leather dye.

The variables are:
- How well the stropping surface conforms to the convex shape.
- Applied pressure during the stropping strokes.
- Angle of attack during the stropping strokes.

Obviously, the leather-on-mousepad strop will more easily conform to the convex curvature than the leather-on-wood strop - for a given pressure during the stropping stroke.

More pressure applied on the firmer stropping surface is about the same thing as less pressure applied on the less firm stropping surface.

Whichever stropping surface selected, changing the applied pressure also affect how well the strop surface conforms to the convex curvature.

The angle of attack - combined with the above variables - will affect the effectiveness of the stropping:
- Angle too shallow may result in not effectively sharpening the edge.
- Angle too high may result in 'rounding' (dulling) the edge.

It will help a great deal to get a feel for conformity+pressure+angle if you mark the area to be stropped - so you can easily see the effect of your stropping. Examples:
- Mark the area with a Sharpie.
- Paint the area with a dye or bluing compound.

You may find it easier to just 'zone-strop' the convex bevel (forget perfect conformity of stropping surface):
- Strop the area just above the edge.
- Then strop to the edge on the next pass.

The one thing you want to avoid is 'rounding' the edge - caused by too much pressure and/or too high stropping angle.

It's going to take some effort on your part to get a feel for the variables involved in stropping, but it'll come quickly with practice.

Hope this helps!

 

[Gossman Knives]

I use an old leather belt (1 3/4" wide) charged with 600 grit aluminum oxide compound clamped to my bench and strop the way the barbers used to. I start at the heel of the blade (near the ricasso) and strop to the point away from the edge. Turn the blade over and repeat.
Scott

 

[Big Bob]

Many of the other posters at the HI forums and I use leather strops for the final sharpening/polishing of our khukuris, which come with convex edges. I made two strops out of an old leather belt and haven't had any trouble with the dye.

Bob

 

[Andy_L]

for thinker full convex grinds I put the leather of the hard side of a mousepad and strop on that

 

[frugalweaver]

On larger knives and my scupture axes I hold the blade edge up on my bench and use my long wood strop with an old belt glued to it. I hold the blade in my left hand and the strop in my right. I start with a low angle and curve the strop into the edge watching the blade to see when I have the center of the edge buffed. It takes a little practice to get it righ but is much easier to see what you are doing and the effect is super.

 

[Cliff Stamp]

More pressure applied on the firmer stropping surface is about the same thing as less pressure applied on the less firm stropping surface.

In regards to curvature induced, however it has a big difference in the cutting action and burr formation. Nice post.

Does leather mounted on wood have enough give for stropping a thick convex edge (.25")?

The spine thickness has little effect, you are mainly concerned about the edge thickness and angle. If the curvature is really steep it will be difficult to match it by relying on the deformation of the media alone so you have to rotate the blade a little. Using this method you can strop convex edges on benchstones by rotating the blade to match the existing angle. It isn't as hard as you might think.

-Cliff

 

[MVF]

Thanks all- great information:thumbup:

 

[Greg]

G'day,
I second frugalweavers hard wood backing for a strop and using it like a file (moving the strop, blade held still). For me there is enough 'give' in the leather to convex the edge.
Greg