What's new
  • Welcome back Guest!
    If you have been away from our site you may have to request a new password. Simply click on the link for "lost" password in the log in page.
    Thank you.
  • Guest
    The BST is now open, please note the changes in our guidelines to address the recent fraudulent activity. Ensure you read the guidelines prior to creating a sale thread in the Buy-Sell-Trade forum with special attention to the new photo and payment requirements.
    Thank you for your patience and understanding.

Edge from Convex Stone. I Think Not

Acmemfg

Ambassador
I have a wonderful LeGrelot which was delivered with an edge done with a convex stone. For whatever the reason, it (the edge) was less than great. That being said, I have made a couple attempts to re-do this razor using other (flat) hones. My most recent attempts were a Naniwa 5K-12K progression (so-so) and a Naniwa 5k to Vermont Green Slate finish (not much better). I have used these hones with fine results in the past; all I can surmise is that the convex edge is not allowing me to achieve the results I desire. Is this going to require me to completely reset the bevel and start all over again?
 
It shouldn't.
The convex edge that's now on it should be easily replaced by whatever you like.
I would think a 5k would do the trick. Drop down to speed up if you like.
Some Grelot's are finicky with some stones.
 
A sharpie pen is your friend. It will tell you a lot about the bevel that you have and sometimes the whetstone that you are honing on.
 
Just wondering. If the convexity of the stone is along the Y-axis in addition to the X-axis, might not a possible increase of pressure during the pass at the X-Y apex in the exact middle of the stone lead to bevel rounding with a hollow-ground razor? If so, then that might account for why it is hard to bring back such an edge on a flattened surface. Following this, perhaps a slackened pasted strop, or even just a plain slackened strop, used on such an edge as received, might improve things rather than a flattened surface.
 
Last edited:
It might be a good idea to check for contact all along the bevel. A hone convexed in both directions would make it easier to get a slight frown going. Make sure that's not happening by either closely examining the new scratch pattern you're creating or even by using Sharpie as already suggested. If that did happen and you're now using a flat stone it won't hit in the center unless you take pains to make that happen or until you reset the bevel so that it's flat again.

If that's not the problem, you may just not have nailed your first attempt. Start over and try again.
 

Legion

Moderator Emeritus
Not knowing how or what convexity was originally done, if you want to change to flat stones I'm thinging you need to start again and set the bevel. That is what I would do, to be sure.
 
Just wondering. If the convexity of the stone is along the Y-axis in addition to the X-axis, might not a possible increase of pressure during the pass at the X-Y apex in the exact middle of the stone lead to bevel rounding with a hollow-ground razor? If so, then that might account for why it is hard to bring back such an edge on a flattened surface. Following this, perhaps a slackened pasted strop, or even just a plain slackened strop, used on such an edge as received, might improve things rather than a flattened surface.
Since I can't edit the above, upon further consideration, if a slackened strop leads to a rounded bevel, then a convex surface would act in the opposite way. So it would seem that edge contact would be there from the start in moving from a convex surface to a flat surface.
 
Yeah, in the direction from the spine to the bevel the arc formed by a convexed hone will be hollow, so upon moving to a flat hone, contact at the apex should be instant. Just gotta watch out for the other direction. Since the convex hone is only ever going to touch the blade with single point contact, it would be able to run all the way full length along a frowning edge, where a flat hone would not - unless a technique is used where the blade is drawn all the way off the hone and is effectively riding on the corner.
 
Since I can't edit the above, upon further consideration, if a slackened strop leads to a rounded bevel, then a convex surface would act in the opposite way. So it would seem that edge contact would be there from the start in moving from a convex surface to a flat surface.
This was my reasoning to say the difference should be easily replaced going to flat.
The slightly concave edge should be quickly ground away on a flat hone to a new edge.
 
was the person that put a convex edge in your le grelot a known (decent) honer? was there issues with this razor before convex hone? I’m a believer in convex stones. However been playing with flat jnats lately. Personally I doubt you would need lower than 8 k to convert. With slurry i am able to convert back to non convex edge on finishing stone with slurry.
 
if razor is hone-able. it should be sharp convex or flat stone..... and easily convertible to flat stone.... there has to be more to this story?
 
I have a wonderful LeGrelot which was delivered with an edge done with a convex stone. For whatever the reason, it (the edge) was less than great. That being said, I have made a couple attempts to re-do this razor using other (flat) hones. My most recent attempts were a Naniwa 5K-12K progression (so-so) and a Naniwa 5k to Vermont Green Slate finish (not much better). I have used these hones with fine results in the past; all I can surmise is that the convex edge is not allowing me to achieve the results I desire. Is this going to require me to completely reset the bevel and start all over again?
If you reset the bevel the first time on a flat stone resetting it again isn't going to change anything
 
Top Bottom