Thread: Should I try to tackle this (very difficult, IMHO) challenge?

Originally Posted by gssixgun

I think we all agree with the "Fact" that the numbers seem "Off"

What do you mean by "Off"? The measurements given work out to 17.6 degrees.

Originally Posted by puketui41

What do you mean by "Off"? The measurements given work out to 17.6 degrees.

Not with 5 layers of tape on the spine...

Yea, stay the course and get it honed for a test shave. If the final angle is within a couple of degrees either side of 17 it has been close enough for me to get a decent shave from. I have a few razors with wide and wavy bevels that shave just fine.

Bob

Yup, good progress, once you get the bevel fully set, it will not take much effort or time to re-set the angle.

Ink the bevels and spend some time on the toe and heel, adding a finger of pressure and get them to meet. It is not uncommon for the heel and toe to need more attention especially with that much wear and tape.

Also, as said, keep the tape tight and change the top layer as it wears. You will see bits of tape in the swarf and feel it on the stone. If you feel a bump or sticking on the stone, stop and check your tape, probably burned through the top layer.

Good photos and progress.

Originally Posted by sqzbxr

Not with 5 layers of tape on the spine...

Yes, but the comment referred to the measurements of the blade without tape. I'm just not clear about what it is we've all agreed upon. Nice job on the edge PCM

Originally Posted by BobH

From what I have read the blade width calculation should be from the edge to where the hone wear is, including the width of the hone wear. That is usually not the top of the spine but slightly narrower. At least that is what I do using the Excel file on this site http://www.coticule.be/wedges.html to do the calculation.

Bob

My calculation was from the edge to the top of the spine. It has rounded top, so yes, it is off (I have tape on there right now, so I can see how far it is from end of wear to top of spine - guessing up to 1mm).

Originally Posted by sqzbxr

Definitely a problem with your numbers. I have run them through my honing log spreadsheet, which has the same formula given by GSSIXGUN plus color coded results based on an optimum blade angle of between 16 and 18 degrees. This is what I get:



Note: You can read the numbers better if you open the image in a new window or tab so that it appears full size.

Some small confusion here...

Is the expectation (by numbers being off), that the angle would be too SMALL and hence tape needed to bring it within range?

If that is the case, I'm confused. My measurement is from edge to top of spine. If we go up to the end of the wear, then that length gets smaller, and thereby the angle gets LARGER, which would then imply that adding tape would make it even worse.

For example, if width is 2mm less -> 0.674, then we get 19 degrees (using arcsin, which really is incorrect, but at these angles are similar), and with 5 layers (10 @ .177mm) we get 24 degrees.

I must be missing something. Can someone enlighten me?

The calculation will vary depending on where you measure the width of the blade, from the top of the spine or the beginning of the spine wear. When you have a few millimeters width of spine wear, that width, can throw the resulting calculation off by several degrees.

The front edge of the wear is probably the best measurement. But just from experience with that amount of wear, that number does look “off”.

I don’t spend a lot of time worrying about the actual angle. Really all that counts is, if it will shave and hold an edge.

Originally Posted by puketui41

What do you mean by "Off"? The measurements given work out to 17.6 degrees.

Originally Posted by puketui41

Yes, but the comment referred to the measurements of the blade without tape. I'm just not clear about what it is we've all agreed upon. Nice job on the edge PCM

Let me see if I can make it clear...

A bevel angle of 15° - 17° is dead nuts normal in fact perfect

Now look at the first pic of the razor in post #1, do you see an issue ???

So obviously this razor is well outside of the norm, the entire geometry has been honed beyond the norm, so the numbers are going to be "Off" unless the razor is reground back into correct geometry..
We have moved beyond the re-grind now, and we are well out onto the experimental limb of the honing tree..

ie: The numbers seem "Off" but he is making progress toward an edge now ..

Hence my statement when I got into this discussion post #6, "I would measure the Bevel angle right now to get an idea of where it is even at, and if there is enough spine left to even do a re-grind.."
It was not even about the bevel angle as it pertained to honing it was in reference to a re-grind possibility...

At post #24 after he was told the bevel angle was high, again I attempted to explain that the bevel angle seemed "off", but he was making progress so to stay at 5 layers and keep honing.
The bevel angle seems "off" because at 17.8° he should need NO tape, or maybe 1 layer to protect the spine, but this razor is not within the norm

In post #30 again I tried to explain that although the bevel angle seems "off", because a 17.8° angle is normal and good, keep the 5 layers because the edge is making progress now..

So again I think we can all agree that the bevel angle seems "off" but he is making progress so stick with it get an edge first, and adjust later if needed..


I hope that helps

Originally Posted by gssixgun

I think we all agree with the "Fact" that the numbers seem "Off" but the results you are getting, show promise, it looks like you are actually getting close to an edge now..

I would NOT change anything until you attain a shaving sharp edge, you can always tweak in the adjustments of a layer of tape after you get there first..

You have been chasing the edge for quite some time putting in some effort to do so, now as you are finally getting close stick with one plan, adjust later if needed


JMHO

Thanks! Been about 1 hour on the 220 grit and 2 hours on the 1K, so not bad timewise so far

I'll keep things the same. Does it look like I need to get the edges meeting better (they seem close)? I can continue and see if I get TPT that seems more sharp (though I'm not real skilled at measuring that yet). Cutting arm hair has been hit or miss for me - as my hair is pretty fine. I guess I could test shave to see.