Sandpaper, Strops and Convexing Your Edges: Advice Needed

[VermontEdge]

Hello hello!

I've been doing a lot of reading of old threads lately but I couldn't quite find the info that I'm looking for. So here's my issue:

I have a sharpmaker but I'm not particularly fond of it. I've been researching different sharpening systems and even just stones for free-handing, but I'm feeling very overwhelmed and torn and I'm kind of going crazy trying to make up my mind.

For the past few years my main sharpening method has been a KSF strop (the little ones in the otterbox). With this system I can place whatever grit of wet/dry sandpaper over the little piece of leather, smooth it out, and sharpen all my knives decently well using strokes that go away from the edge (pulling rather than pushing).

This, however, has started to convex pretty much all of my knives.

Is this a problem? For any reason? I'm contemplating just buying a larger strop set up to continue using this sandpaper method as I find it intuitive and forgiving in terms of getting an exact.

For example, though, I worked on my Spyderco Temperance 2 last night. I got it sharp enough that it slices tomato skin without any pressure (just pulling it across) and yet I was having trouble getting clean cuts on printer paper. My theory is that the convex edge is very sharp but maybe requires a more precise cut when trying to slice paper. Does that make sense to anyone?

As long as there are no disadvantages to gradually convexing all of my knives I'm perfectly happy staying the course. I just want to be able to sharpen my knives well and maintain them, and if the best way for me to do that is to end up with a bunch of convexed edges, that fine by me, provided that there's no reason not to do this.

Yikes. Long, slightly venting post. Apologies. Anyway, I'd really appreciate anyone's opinion or thoughts on the matter.

Thank you!

:thumbup:

 

[Obsessed with Edges]

Don't worry about convexing in itself. I'd focus on moving toward a firmer backing under your sandpaper (such as wood), to minimize the additional rounding or thickening of the edge (apex) itself. To make the edge sharper, focus on lowering the angle used when sharpening over firm/hard-backed sandpaper. It'll still be convex, if using the same technique as always; but it'll be a thinner & more subtle convex, finishing with a crisper apex. Also consider affixing the sandpaper to the hard backing with adhesive (some temporary adhesive that can be peeled off is great for this) or doublesided tape. That'll prevent the paper from lifting & rolling over/around the apex as you work (which will round off the apex). All these things in tandem will greatly improve the quality and sharpness of your edges.


David

 

[VermontEdge]

Don't worry about convexing in itself. I'd focus on moving toward a firmer backing under your sandpaper (such as wood), to minimize the additional rounding or thickening of the edge (apex) itself. To make the edge sharper, focus on lowering the angle used when sharpening over firm/hard-backed sandpaper. It'll still be convex, if using the same technique as always; but it'll be a thinner & more subtle convex, finishing with a crisper apex. Also consider affixing the sandpaper to the hard backing with adhesive (some temporary adhesive that can be peeled off is great for this) or doublesided tape. That'll prevent the paper from lifting & rolling over/around the apex as you work (which will round off the apex). All these things in tandem will greatly improve the quality and sharpness of your edges.


David

Great! Thanks!

Follow up question:

I'm thinking about buying a four sided strop. 3 sides have leather for compound, and one is just flat wood. The system come with a way to attach sandpaper to it. Does that bare wood side seem like it would work as a harder back? And then I can finish with compounds?

Also, do you find this sandpaper with a hard back technique to work well if still using strokes away from the edge?

Thanks a million! Excited to get a good system in place

 

[Obsessed with Edges]

Great! Thanks!

Follow up question:

I'm thinking about buying a four sided strop. 3 sides have leather for compound, and one is just flat wood. The system come with a way to attach sandpaper to it. Does that bare wood side seem like it would work as a harder back? And then I can finish with compounds?

Also, do you find this sandpaper with a hard back technique to work well if still using strokes away from the edge?

Thanks a million! Excited to get a good system in place

I don't see why that couldn't work. Just try to make sure the paper stays taut & flat to the backing, so it doesn't lift under pressure from the blade; if the system allows for it to be stuck/adhered down on the wood, so much the better. Finishing with compounds should also work well; plain paper, like printer paper, could be used in the same way as the sandpaper, with compound applied (could also use fabric like denim or linen; both work well). And for sandpaper sharpening, I generally always recommend edge-trailing strokes anyway (away from the edge), no matter what backing is used under the paper. That'll protect the paper from getting cut by the edge and will also be better for the edge itself, as it can be dulled if it cuts into the paper & abrasive.


David

 

[HeavyHanded]

Great! Thanks!

Follow up question:

I'm thinking about buying a four sided strop. 3 sides have leather for compound, and one is just flat wood. The system come with a way to attach sandpaper to it. Does that bare wood side seem like it would work as a harder back? And then I can finish with compounds?

Also, do you find this sandpaper with a hard back technique to work well if still using strokes away from the edge?

Thanks a million! Excited to get a good system in place

If the backing is hard enough and the paper tight to it, you should be able to do at least some leading passes as well. To start, just use those trailing passes, but you might find for clean deburring that some light leading passes are priceless.

You might want to take a look at the sharpening block I make (link in my signature). Uses wet/dry, copy paper, lapping film, etc and can be made as soft or hard as you like.