Honing a warped razor

[psfred]

Just got a beat up rusty razor off ebay , no idea what it is because I've not un-pinned the scales yet to clean up that part well enough.

Rust is surface for the most part, cleaned off well and the end, although rough, is not pitted so I started honing.

It's warped, about a third of the edge doesn't touch on the hollow side and the convex side only hones maybe 2/3 in the middle. Appears to be nearly unused, the existing bevel was tiny, so I'm assuming it was honed on a narrow stone. Edge looks like a frown, but against a straghtedge it's slightly convex, which is fine.

Any advise? I see my options as grind down until I get an apex and risk a frown, do lots of heel to toe on a stone, or hone with a narrow hone and work with the frown, probably on a slightly convexed hone. I'm leaning toward the latter, no point in hogging off a lot of steel to get an unusable razor.

I suspect a narrow hone was typical back in the days this thing was new, and there isn't much reason to correct the warp if you can hone it sharp with the warp in place on a narrow stone.

 

[JPO]

For these types of blades I use a convex stone for 90% of the work. I then finish on a flat stone with some rolling x-strokes.

 

[Herrenberg]

For these types of blades I use a convex stone for 90% of the work. I then finish on a flat stone with some rolling x-strokes.

I can see how a convex stone would help with the concave side of a warped razor. How does it help with the convex side?

 

[JPO]

I can see how a convex stone would help with the concave side of a warped razor. How does it help with the convex side?

I don't see why there would be a big difference from one side to the other. You are isolating a smaller contact area on the stone. The only thing that change is the angle as you manipulate the contact with the stone.
When I use these stones this is not something I even think about.

 

[Steve56]

Rolling X stroke on the convex side, on the concave side use the corner of a stone to ‘ride’ into the hollow. Or a narrow hone. If your synths are 1” wide, you can use the side of the hone.

 

[Empire straights]

Use a skinny stone. My ½"x½"x5" Tam O'shanter "sticks" are really good for badly warped blades(it makes a good stone file too).

 

[H Brad Boonshaft]

Post clear photos of both sides for better advice, but likely as said, a Rolling X stroke will get an edge on it without a frown.

 

[psfred]

Tried it on the sides of my stones tonight after flattening the stones, seems to have a decent edge. Will see how it works sometime over Christmas when I'm off for a week and have time to play with straights. Not something I want to do while getting ready for work!

 

[JPO]

Rolling X stroke on the convex side, on the concave side use the corner of a stone to ‘ride’ into the hollow. Or a narrow hone. If your synths are 1” wide, you can use the side of the hone.

View attachment 1750687

When you hone the concave side of the razor utilizing the corner like this you introduce allot of geometric challenges in my opinion. For the bevel to have contact along the full bevel flat the distance to the contact point on the spine relative to the edge is important. This will change when the stone is used like this. These contact points will also wary as you hone, and make it difficult to obtain a flat bevel.
As you get close to the corner of the stone with the leading edge you will most likely just grinding at the shoulder of the bevel.

Anyone can test this using a honing rod for knifes. If you use a razor on it at say 45 deg, you will not be hitting the full bevel plane, only the bevel shoulder.

The Turn of the Skew

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[Steve56]

Usually when you have to resort to techniques like this there are a lot of other things going on too, so although your comment is true for a straight edge and an even bevel, I’m not sure how it applies when the bevel is not a uniform width, and in many cases the spine is not either, from wear. And of course, as stated the razor is not flat. So there are a lot of wonky things that are usually going on in these instances, not just one. Also I use a circular and elliptical motion to ‘blend’ the honing wear along the bevel.

 

[JPO]

Usually when you have to resort to techniques like this there are a lot of other things going on too, so although your comment is true for a straight edge and an even bevel, I’m not sure how it applies when the bevel is not a uniform width, and in many cases the spine is not either, from wear. And of course, as stated the razor is not flat. So there are a lot of wonky things that are usually going on in these instances, not just one. Also I use a circular and elliptical motion to ‘blend’ the honing wear along the bevel.

Yes. There is allot of things going on. It all comes down to the experience of the person honing the razor. Sometimes overthinking might get in the way of actually feeling what is going on between the steel and the stone.

My problematic razors are far less problematic today then they once were I don't think those razors have changed much from being stored.

So, one solution for some might be to get some experience honing razors with good geometry, and have a go at the more challenging razors later.

 

[psfred]

I'm not too worried about the geometry at the edge, I'll be happy if I get an apex and the edge isn't a frown.

The fact the razor appeared to have never been fully honed might be due to the warp, or just never sold and sat in a drawer for 70 years. It was rusty, but the edge seems good with no pits, and I paid next to nothing for it. Will need new scales too, one is broken at the pin like usual.

If it shaves I'll put some nice exotic wood scales on it eventually and use it -- or sell it to someone who can.

 

[JPO]

I'm not too worried about the geometry at the edge, I'll be happy if I get an apex and the edge isn't a frown.

The fact the razor appeared to have never been fully honed might be due to the warp, or just never sold and sat in a drawer for 70 years. It was rusty, but the edge seems good with no pits, and I paid next to nothing for it. Will need new scales too, one is broken at the pin like usual.

If it shaves I'll put some nice exotic wood scales on it eventually and use it -- or sell it to someone who can.

Can you post a photo so we have a little more meat on the bone?

 

[Seelector]

The concave side of a warped blade is tricky to hone. I don't have a narrow hone, so I basically do an upside-down rolling X-stroke on the concave side:

• start the stroke as you normally would with an unwarped blade. A little pressure on the heel and/or the toe off the stone a bit. This will hone the heel to 1/3ish blade span.
• Continue your x-stroke with the heel dropping below the plane of the hone. This works the middle 1/3 of the blade. All the honing happens in a narrow strip along the edge of the hone.
• Continue your x-stroke and bring the heel back up to the plane of the honing surface or a little above to get the outer 1/3 to the toe

In @Steve56's picture all the swarf is in a 1" wide strip along the edge, with some concentrated swarf right along the corner. This is exactly the swarf pattern I get when honing the concave side. Actually I bet Steve adn I are saying the exact same thing.

 

[psfred]

Will try today, otherwise next week, gonna be out of town for T-day.

 

[H Brad Boonshaft]

It is more difficult to describe than to do. The trick is to drop the heel off the stone on the concave side to hone the middle using one inch of the stone as in Steves photo, (light swarf).

Most razors have a very slight warp and just hanging the heel off the stone will get it honed. A few heel forward strokes will fully hone the heel.

The convex side just needs to roll from heel to toe to hone the whole edge, again the amount of roll is very slight. Colored sharpie ink will quickly tell you how much to roll, lift the heel.

Ensure that the stone’s corner is beveled or rounded with no sharp corner.

Yes, if you skew the blade, you can change the angle, so don’t skew the blade “that much”. Here again ink on the bevel will tell you what is happening on the bevel, and you adjust.

I have purchased many a pristine vintage razor with a slight warp and little to no spine wear. The owner tried to flat hone the razor, could not and put it away.

The trick is ink and a light hand, add pressure and you can hone a frown.

 

[Frank Shaves]

I just went through this with two warped razors with a third in the queue.

Use whatever strokes and whatever parts of your stones necessary to get every mm of both sides of the edge to make contact with your stones. This helped me:

1. Divide the edge into four to six sections.
2. Practice short rolling x-strokes over each section to learn the edge.
3. As you begin to catch and ride the edge, increase the length of your strokes.

Rolling means constantly adjusting your stroke to maintain contact with the stone as the stroke progress over the hills and valleys of the edge. If you wipe out, get back on your board and catch the next wave.

Bart said this on the coticule.be site - now archived on the shaving universe site:

• It is advisable to always put at least a minimal hint of roll in your strokes. On most razors, not so much a real roll is called for, but rather a gradual shift in pressure: first on the heel, over the middle to end on the tip. And the reverse of that while pulling the razor back during halfstokes.
• Before starting halfstrokes [and rolling x-strokes], always take a moment to seek the right rolling curve for that razor. This can be achieved by performing a few slow X-strokes while closely monitoring how the fluid behaves in front of the edge. Basically, it has to first run up the heel, evolve to running up the middle halfway the stroke and run up the tip near the end of the stroke. 3 or 4 careful X-strokes is generally sufficient to find the right motion and lock it into muscle memory. Next, start the halfstrokes [and rolling x-strokes] with the same curve.