Warped edge remedy

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brothers
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Warped edge remedy

Post by brothers »

What's the recommended remedy, if any? One of my first straight razors is a very old but pristine Joseph Rodgers & Sons slightly hollowed wedge. Over the years I've never been too happy with the way it shaves and I hardly ever use it because it disappoints no matter how carefully I try to hone it conventionally. Two or three years ago I was looking at it and noticed that the edge indicates a mild warp in the edge. The toe of the show side tends to want to go south, and the center/heel of the edge wants to go back north. This probably explains why such a nice old razor ended up in a flea market. It's not visible looking down the edge, but when it's laying flat the pattern that results from being sharpened shows a wide edge on the toe of the show side and thin running to the other end. Flip it over, and the visible edge is just the opposite, thin in front and wider going back.
Last edited by brothers on Sun Aug 30, 2020 9:29 am, edited 1 time in total.
Gary

SOTD 99%: Monday, Wednesday, and Friday, soaps & creams, synthetic / badger brushes, Colonial General razor, Kai & Schick blades, straight razors any time, Superior 70 aftershave splash + menthol + 444
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drmoss_ca
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Re: Warped edge remedy

Post by drmoss_ca »

If you mean the bevel is wide at the toe on one side, whereas it is narrow on the other side in the same place, with the situation reversed as you move back to the heel, you are indeed looking at a warped blade. This either means the edge has an s-bend in it when looked at from underneath, or that the spine is uneven in thickness. It's most likely the former. You can't hone it properly as when placed on a stone, the edge will not lie flat, or if only a small warp, may look flat and in contact, but has more pressure one part and less on another. Sometimes people try to regrind a razor, but it rarely works out well, and often leaves it pretty ugly, with obvious uneven wear on the spine, or a blade that is now considerably narrower. Sometimes gring a smile will remove the worst of it.
The cheating fix is to try to hone it with pastes on hanging strops, hoping the strops will deform enough to give some abrasion to all of the edge.
A better, but more difficult fix is to hone using 'rolling X-strokes', which try to put the hone to work on one spot at a time along the edge. Lynn knows how to do it:



The third and final way is to do what a number of Solingen makers do at the factory as a way of coping with imperfectly ground razors, which is to use a convex hone. This is convex both lengthways and across the hone, and when used with an ordinary x-stroke, only two points of contact exist at any moment - on the spine and on the edge. As the razor is drawn down the points of contact move along the razor, and everywhere get the same attention even if the razor is warped.
thesuperiorshave.com sells Arkansas stones laboriously polished into this convexity, and some people will use their nagura when cleaning swarf off a hone to rub more around the edges than in the middle to encourage a similar shape. Some hones come molded that way without it being announced; the first full set of Superstones I had turned out that way, and I never knew it until I decided to lap them with a DGLP and I started to find an elliptical flat spot forming in the middle of each. When I replaced them, I made sure not to lap them at all!

Is it worth it? That probably depends on how much you need a new letter knife, which is how I treat most of these dogs.
"Je n'ai pas besoin de cette hypothèse."
Pierre-Simon de Laplace
brothers
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Re: Warped edge remedy

Post by brothers »

Thanks Chris, for the detailed response and Lynn's excellent video. This is one of those days when I have had the time to focus on a razor issue without interruption. Earlier this afternoon I read someone's mention of the possibility that the spine isn't absolutely flat on both sides. It makes sense that the spine/edge relationship is critical. I checked into that possibility on the Rodgers, and it turned out that neither the show side nor the reverse side of the spine were flat and parallel to each other. The spine was curved - larger on both ends and smaller in the middle.

This old Sheffield had no visible spine wear. I confirmed the fact the spine was irregular by marking each side of the top of the spine with a black Sharpie and using some fine sandpaper on a flat piece of marble (I used 2000 grit paper) to sand off the marked high points and leave the low places black. With that factual information in mind I taped the edge and used the DMT D8E (1200) and EEF (8000) stones to flatten both sides of the spine.

Now I am very curious to run the edge through the honing regimen as indicated by Lynn's rolling X, etc.to see if anything changes regarding the bevel. I have always naively believed the spine of every straight razor to be flat and parallel on both opposing sides. Live and learn! I'm certainly not jumping to the conclusion that this razor is now fixed, instead, it's just another wrinkle.
Last edited by brothers on Sun Aug 30, 2020 9:23 am, edited 1 time in total.
Gary

SOTD 99%: Monday, Wednesday, and Friday, soaps & creams, synthetic / badger brushes, Colonial General razor, Kai & Schick blades, straight razors any time, Superior 70 aftershave splash + menthol + 444
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drmoss_ca
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Re: Warped edge remedy

Post by drmoss_ca »

Frankly, I'm surprised most razors do come out acceptably straight when it's all done by eye!
"Je n'ai pas besoin de cette hypothèse."
Pierre-Simon de Laplace
brothers
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Re: Warped edge remedy

Post by brothers »

Today's SOTD was the test of the updated Rodgers. My straight razor shaving skills are average at best, but the good news is that now the old Rodgers razor cuts my whiskers in a way that is entirely different and entirely positive compared to what it used to be before trying to save it. My beard this evening was a 36 hour beard, and the razor's performance exceeded my cautious expectations. I missed a few spots, especially around my chin and lower lip, but in the easy places where I must have been doing something right it was a pleasantly smooth result. I bought this razor cheap at a flea market 11 years ago and didn't use it much because it just wouldn't cut a lot of whiskers. Now it is suitable to be compared to my other old Joseph Rodgers razor that has always been a pleasure to use. Now I'm looking forward to using it more often.
Gary

SOTD 99%: Monday, Wednesday, and Friday, soaps & creams, synthetic / badger brushes, Colonial General razor, Kai & Schick blades, straight razors any time, Superior 70 aftershave splash + menthol + 444
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drmoss_ca
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Re: Warped edge remedy

Post by drmoss_ca »

Now you'll have to remember what you did next time it needs honing!
"Je n'ai pas besoin de cette hypothèse."
Pierre-Simon de Laplace
brothers
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Re: Warped edge remedy

Post by brothers »

Very good and very timely advice! Especially in my case! :D Upon reading this, I wrote it all down. Even the part about always using the loupe. The last list I found was from 6 years ago and it was nonsense compared to what I actually had done a couple of days ago. Thank you for your support Doc Chris!
Gary

SOTD 99%: Monday, Wednesday, and Friday, soaps & creams, synthetic / badger brushes, Colonial General razor, Kai & Schick blades, straight razors any time, Superior 70 aftershave splash + menthol + 444
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