convex Arkansas translucent purchase do I flatten or leave?

[Blade_Runner37C]

thank you legion, I'm sure there are some books I could purchase also, maybe some college courses I can look into enrolling in. My apologies for just wanting a quick answer and enjoy talking and conversing with people. No need for the face palm and head slap sarcasm.. Once again sorry for bothering you with such a stupid moronic dumb question. I'll figure it out from now on, on my own.

 

[Legion]

thank you legion, I'm sure there are some books I could purchase also, maybe some college courses I can look into enrolling in. My apologies for just wanting a quick answer and enjoy talking and conversing with people. No need for the face palm and head slap sarcasm.. Once again sorry for bothering you with such a stupid moronic dumb question. I'll figure it out from now on, on my own.

OK. But to find all that info I linked to, all I did was take a moment to click that search button at the top right and type in the word convex.

Before you start a new thread it is always best to try that, because, especially in the honing section, you will most often find a ton of info has already been written for you, and there are a heap of discussions already started that you could continue.

The other day you lamented that there was hardly any response to one of your new threads. But part of the reason for that might be that people are getting tired repeating the same answers many times over.

This section is already a fantastic resource of info if you look.

 

[LJS]

@Blade_Runner37C don’t get too sensitive over it. It’s not as much your fault as this has been an annoyingly controversial discussion on this forum in the past. At least to those of us who don’t care to see a bunch or arguing. And legion is totally right, much can be searched up that just gets repeated. But when a lot of folks said “not it” initially, it is because this has been a hot potato topic here where many have fought it out to die on the cross of their opinion. Many have to go back to their corner mad at those who don’t agree. Welcome to opinions and this one has been a very opinionated discussion you can see searching back. So most folks would prefer not to open this opinionated fight back up because it often spirals into arguments and a closed thread. So there is your answer and don’t take it personal because it was a bit of a problem before you. And like many razor honing questions, there is not an exact 1-2-3 process that everyone prefers or is the only correct way. There would be just one instructional post saying “do this” and there would be no forum or discussion. What works for some does not for others. That’s ok. Find what works for you. There are some absolutes we all agree on like (1) setting a bevel and proper edge is paramount to success, (2) removing all lower grit scratches leads to nice shaving edge………well and that may be it Maybe also agree on light/no-pressure but I’m sure someone will argue. I’m saying this to reiterate what folks are advising you when they say there is no correct answer other than what works for you. Read the opinions, take some test runs yourself, and make your own decision. That is the real answer. Many questions have been answered many times and the search function can help. If you ask about a hot topic then many will want to avoid any unnecessary arguments and who could blame them - convex hones have been one of those topics so just be aware. If you like the convex then great. If not you can change it like others have said. Also may want to heed slice’s advice and recognize others may find more value in the stone than you do and you may be able to trade up for a flat stone. Lots of options. And even more opinions. At some point you have to make your own and this forum will completely resolve very few of those for you….but is great about putting you in the right direction to form your own opinion.

 

[natto]

I would like to keep the stone but no one has mentioned how to use the convex (post #36).

The short side looks convex. That shape can be used to sharpen razors with a recurve. I would like such a stone for my warped razors.

And there are stones which show a convex long side. That may be a good thing, if you know how to use it. If I got it right, some post are commenting convex along the long side. I mean that "be careful" posts.

Or have I misunderstood this thread?

 

[JPO]

thank you legion, I'm sure there are some books I could purchase also, maybe some college courses I can look into enrolling in. My apologies for just wanting a quick answer and enjoy talking and conversing with people. No need for the face palm and head slap sarcasm.. Once again sorry for bothering you with such a stupid moronic dumb question. I'll figure it out from now on, on my own.

Asking questions about the use of convex hones here is like walking into a flat earth conference and pointing out the pink elefant in the room.

The good news is that you are just one post away from being an expert.

This is not a figment of my imagination.

Someone claimed that you would drive the edge in to the convex hump and create a convex edge, and not a concave bevel.
By pointing out that this is the complete opposite of what's going on (pink elefant) you will be called a bully by a moderator. Yes, this actually is what happened.

It's really difficult to descuss e.g. the universe when people are sailing over the edge of the earth.

This actually also happens during private messaging. You spend allot of your valuable time explaining something, then, after a while you are recovering from the Stockholm syndrome. So, sorry for being a little short in my answer earlier.
Other people's time is the most valuable commodity they have, and shouldn't be taken for granted. People are generally helpful if you put in a little effort before asking questions.

 

[psfred]

As far as actually using a convex hone, remember that since the stone is convex only a small portion of the razor edge is in contact and any time, pretty much forcing you to use X-strokes so the entire edge is honed. Absolutely use minimal pressure for the same reason, any downward force on the edge is being applied to a very small part of the edge.

Warped razors would be much easier to hone on a single convex hone (only across with narrow side) as you won't have the ends or center riding higher that the rest of the blade. Check that stone and see if it's flat along the long dimension.

Double convex or convex along the long axis is different as the stone will abrade in the middle of the bevel until a matching concavity is ground into it, so you would really need all the stone in a progression to have the same convexity. Going from a flat intermediate stone to a convex finisher would entail a very large amount of work to get to the actual edge.

It's just another way to get a keen razor edge, not a religion. The biggest issue with convex stones appears to be keeping the convexity matched to reduce extra work, not the final edge or ease of use.

Note that hand flattening stones against an abrasive plate tends to result in slight convexity anyway since pushing pulling the stone applies more force to the edges than the center.

 

[Empire straights]

finally picked me up a 6x2x1 Norton Translucent for $26 only thing is it is convexed for straight razors, I asked a gent on here but didn't understand the answer. Should I flatten it or is convex helpful? I have zero experience with a purposely convex stone usage.

Thank you for any information you can share.

To avoid a fight on the board, I invite you to do what I did with the LG thuri I bought that was convex. Make sure the other side is good and flat and use the bump of the convex side to suit in your palm giving you better stone control. Feel free to try the convex side street you finish on the flat side, if you're so moved, but I never have. Supposedly this is how razor makers in Soligen finished razors, which wouldn't surprise me since they did so much grinding on a wheel, which is by default a convex surface. I'll try mine one day though.

 

[Empire straights]

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To add an addendum to my previous statement... yours is much less convex than mine. I've honed knives and razors on stones that were more out of flat than that. The key is to make sure you have an even contract point and move it evenly and smoothly across the bevel. Especially on a translucent Ark. A mis step on an ark can eat your whole edge really quickly. It helps though that with a razor you'll be using ZERO pressure. You could try some spine leading strokes are well, it might help keep you from digging the edge in.

 

[Empire straights]

The short side looks convex. That shape can be used to sharpen razors with a recurve. I would like such a stone for my warped razors.

And there are stones which show a convex long side. That may be a good thing, if you know how to use it. If I got it right, some post are commenting convex along the long side. I mean that "be careful" posts.

Or have I misunderstood this thread?

Those little 1"x5" white Tam O'shanter sticks are fantastic for warped razors.

 

[SliceOfLife]

You use it the same you would a flat hone, just much more carefully.

99.999999999% of what a convex hone does is isolate a much smaller portion of the edge so the hone works faster.

I wasn't here when all this evident drama around convexing went down, but I buy old stones that are naturally quite convex and I am lazy, so I've honed on convex stones plenty.

I'm of the opinion that all the theorycraft and maths around proving that they change bevel geometry is just the latest version of the argument guys (some who were selling junk paver stones as hones that didn't work without slurry) used to make that slurry does the same thing. You get good results with something, want to explain it, search for an answer and guess what, find one that makes what you are doing "the right" way. Steel holds the edge radius it's gonna hold. What it will do if you attempt to exceed what it's capable of (either in refinement or edge angle), is fail. And when it fails during an attempt to concave the bevel immediately behind the edge, it does exactly what you'd think... rounds off the edge at the point of failure. So BEST case, if you assume the "concave" happens. What happens is a concave primary bevel followed with a convex secondary bevel. This is unavoidable. This is how metal works.
Steel just doesn't tend to behave the way where honing on a convex surface is a benefit for ultra-high levels of refinement. If it were, you'd finish grinding your knives on 10k grit wheels, not switch to stones... like everyone does.

What a convex hone (and via a different mechanism, slurry) DOES... is speed the honing action up by increasing the pressure used via reduction in contact between stone and razor (and likely increased force needed to keep razor contact consistent on an unlevel surface).
I'd be shocked if there's any consistent reduction in edge angle or radius immediately behind the edge with almost ANY change in stone or technique. Further back? Sure... But that's the opposite of what you want for shaving. Someone claimed somewhere that with razors only the first XYZ microns of bevel thickness matters. Can't recall the number they gave, but it was LOOOOOOW. Edges thin because the steel is removed. Edge recesses because it fails. Concaving behind the edge is not ever going to be beneficial with an edge this thin. You're just recessing it faster. And that Convexes it because as steel approaches failure, plastic deformation allows the edge to clean. It's essentially the fundamental reason you can hone at all. If you ignore that, sure, convex honing does what it's proponents assume... but if that's true, honing itself becomes impossible You just create an infinitely growing (to razor depth) wafer of steel that reduces to a single molecule thickness.




And I don't think @Legion was trying to be rude. Since I've returned, I get the impression that there's a tendancy for the flavor of the month Youtuber fans to come around and try to start arguments in support of whatever youtube expert they're a fan of, which the moderators have to struggle to keep from getting nasty, so there's always a suspicion of guys who are 'innocently' asking to reopen discussions that have been debated ad nauseam in the past. Hence, I think those inquiries tend to get referred to prior conversations.


I'm no fan of convexing the edge deliberately either. But everyone knows that if you have a razor that isn't holding the angle it's at... You finish on a pasted strop to get that little bit of convexing. Most of the time it'll hold a much finer edge that way. Razors that fail at 6k JIS will hold 0.1 micron off a strop sometimes. So that's at least useful. Doing the opposite... well... does the opposite. I'm of the opinion that neither is an improvement on a simple bevel that is at the appropriate angle for the steel quality and refinement level chosen. I suppose functionally, a convex hone might help with a razor that's ground at too high an angle... but I'd consider it far too imprecise to be useful. Still if you've got a wedge someone taped and ground back and now it's at 25 degrees... Yeah worth a try... Probably applied right, it's gonna help undo some of the problems with that razor.

It's not gonna improve a 15 degree Wonderedge though. You're just gonna push the edge back. And that's where this failing to understand the mechanism of what your doing becomes a problem, you aren't able to apply it properly if you just decide it does whatever makes it a panacea.

 

[SliceOfLife]

So a TLDR:
Convex hone deflects the edge more in honing (obvious, I know)
Because of how honing works, this recesses the edge
This increases total edge angle & Edge radius (Convex honers STRONGLY imply the opposite is true, which is my fundamental issue with their claims).
This effectively Convexes the edge, not concaves the bevel (in a meaningful way for shaving).
The concave effect on the bevel on a (very key note) properly ground razor, actual is either negligible or a detriment, as you've actually increased your effective edge radius and then added convexing further back in the bevel, where it's irrelevant to shaving.

Concaving the primary bevel in OTHER applications (woodworking), worthwhile. Shaving? Not typically.


But all this is on a small enough scale, the effect is gonna be far, far, far less noticeable than the much simpler effect of reducing contact area of razor to hone increasing the rate of steel removal. So what blows my mind is people will pay a massive premium for a 3" wide hone over a 1.5" wide one, then pay more to convex it, so less than 1.5" width is in contact with their razor anyway.

 

[JPO]

Life is too short.

 

[Darth Scandalous]

Without getting into the weeds of the theory behind it, my suggestion remains the same, try it. Specifically try starting on the curved stone and finish on your flat stone, maybe a 1:2 ratio of lap count from the curved to the flat. I have a 6x2 tranlucent with a mild hump and using it prior to my flat one seems to speed up the process some. It would be helpful if you had some experience finishing on your Dan's black to know if the curvy stone is doing anything for you or not.