Thread: Experimenting with some jointing techniques

Originally Posted by Grazor

Been playing with jointing the edge for a while, depending on condition of razor. Found the corner of the hone a bit harsh, the TNT works better for me, does the same thing. Basically you are bending the fin over and knocking off the high points at a molecular level.

Seems this is one of those "whatever works" threads.
One thing is for sure, once you get that edge right all you need to maintain that edge is a lead dressed strop ...

Oh boy.

The Science of Sharp guy, some of whose stuff needs to be taken with huge grains of salt, has some photos of a killed edge. The edges were killed on glass and the photos showed that the edges were folded over into a drastic "J" shape. When "jointing" is done along the corner of a hone, the effect may or may not be the same. I honestly don't know. It certainly is not at a "molecular level," but if jointing actually is beneficial, then I doubt if the edge is folded over in the way that it is on glass.

Originally Posted by Grazor

One thing is for sure, once you get that edge right all you need to maintain that edge is a lead dressed strop ...

What kind of lead are you using ? powdered, white lead powder used for paints, bar of lead rubbed on the leather, ?

Originally Posted by randydance062449

What kind of lead are you using ? powdered, white lead powder used for paints, bar of lead rubbed on the leather, ?

Here is the thread about them. Made my own with a piece of roo leather.

Originally Posted by Utopian

Oh boy.

The Science of Sharp guy, some of whose stuff needs to be taken with huge grains of salt, has some photos of a killed edge. The edges were killed on glass and the photos showed that the edges were folded over into a drastic "J" shape. When "jointing" is done along the corner of a hone, the effect may or may not be the same. I honestly don't know. It certainly is not at a "molecular level," but if jointing actually is beneficial, then I doubt if the edge is folded over in the way that it is on glass.

Have seen that but not tried his techniques.
I would regard the glass as "killing" the edge, and bread knifing for chip repair and taking out a frown etc.

Most of us have seen the edge under a microscope. The higher the magnification, the scarier it looks.
With the edge being 0.35-0.45 microns shown here, maybe molecular is not the right term, micron?

Was more an attempt to explain the concept to anyone reading the thread who hasn't heard of it. Someone explained it much better than I ever will, but can't find that post. I just see those high points as weak steel that will easily bend or snap off, giving a straighter and smoother edge, resulting in a smoother shave.
I noticed a similar effect when I first started honing from the strop, with the 3rd or 4th shave being smoother than straight off the hone. You're doing the same sort of thing, knocking off and re-aligning the fin that has collapsed from the shave. The stronger edge remains.

Originally Posted by Grazor

Have seen that but not tried his techniques.
I would regard the glass as "killing" the edge, and bread knifing for chip repair and taking out a frown etc.

Three things are being discussed here.

1. Bread-knifing is, as you said, for edge re-programming.

2. Killing on glass is to deliberately dull the edge in order to help a beginner be able to assess when he has brought the edge back. When the bevels are set the edge feels sharp again.

3. Jointing is not, in my opinion, the same bread-knifing. Jointing is done (in theory) to remove the saw-toothed edge that is the result of bevel scratches reaching all the way to the apex of both bevels.

Since I've started with these techniques I've seen a notable difference in my results on the HHT. I used to see pretty poor HHT results prior to stropping but my blades are now giving good results straight from the stones and outstanding results after stropping. The shaves have also been constantly great with no need to take any blades back to the stones after the shave test(for fine tuning). As Utopian has suggested, I'm trying to figure out which techniques are more effective at different points in my progression.

Been very busy lately and have not been doing much honing. I finally got a chance to get a couple blades knocked out tonight and switched it up a bit for the sake of experimenting. I honed a G&F Adoration and another blade called Crosby Special. Both were lightly downstroked on the 1k after the bevel was set. I only did the thumbnail downstroke on the Crosby on the following stones and not the Adoration.

The results seem to be telling me something. The Crosby did well on the HHT before stropping and the Adoration did not. The Adoration tested well after stropping and the Crosby was outstanding. I did the thumbnail downstroke on the Adoration and brought the edge back with about 15 strokes on the 8k and finished it again on the 12k. The Adoration then tested like the Crosby both before and after stropping.

It seems that the thumbnail after the 5k and 8k is certainly doing something positive for my progression. I'll repeat this with two more blades before trying to sort out the 1k jointing on the hone.

Random thoughts...do we know the steel type and temper of both of those blades? Simple variance of hardness could account for differing performance. To really test the theory that thumbnail testing is causing a difference in performance you might have to repeat the test, but this time swap which blade you used thumbnail strokes on.

One more thing to test if you haven't, perhaps with a third razor that needs some attention - stropping between hones seemed to have a positive impact on my results.

when I do a thumb nail stroke, I usually do 5 to 10 more strokes on whatever hone I was on before moving forward just to 'get the edge back.' Which kind of has me wondering if perhaps what these things are actually doing, at least in my case, is really just enforcing what I've already done on a certain hone/level and making sure I spend an appropriate amount of time at this level or that before moving forward.