Spine Thinning?

[rbscebu]

I have just ordered a new 6/8 Titan ACRM-2 T.H.60. This SR with a hardness of about 60 RHC, normally comes with a not-shave-ready edge and a designed bevel angle of about 18.5°. My thought are to modify this SR by reducing the spine thinness to achieve a bevel angle of about 16.5° to 17°.

I have no power tools available, except for a Dremel. I was thinking of using a 400 grit Chinese synthetic whetstone (after lapping flat) to grind the spine down. I will need to remove about 0.25mm to 0.3mm from each side of the spine. Your thoughts?

 

[Herrenberg]

I did exactly the same to my T.H. 70, and for the same reason. I no longer remember what stone I used, but it was probably the Shapton Glass 500, so about in the same grit range. I bore down hard on the spine with my thumbs, so there wasn't that much effect on the bevel.

 

[rbscebu]

@Herrenberg, that would have required some work with the much harder steel. Did you measure the resultant bevel angle and how did it shave compared to the old bevel angle?

 

[alex1921]

You can always tape the edge during the spine thinning.

 

[rbscebu]

I will probably tape the edge while grinding off most the spine metal. Once near the end, I will look at more grinding of the spine to reduce the observable increased spine wear.

 

[Steve56]

A diamond plate or a 320-ish to 500-ish stone should make short work of it.

 

[Herrenberg]

@Herrenberg, that would have required some work with the much harder steel. Did you measure the resultant bevel angle and how did it shave compared to the old bevel angle?

I was so sure that I had made a spreadsheet with all the details, but it's not turning up. Yes, it was quite a lot of work. I think I aimed at 16 degrees, measuring the spine width with a micrometer as I went, but without my notes, I cannot be sure of that number.

As for the shave, it has been a while. I recall that it felt much more like my angle, but it didn't change things enough to overcome my annoyance with the heavy, floppily-attached scales. So I put the razor aside and thought of other things. Probably time for me to break it out again and give it a spin.

 

[Tomo]

+1 for the Atoma diamond plate. A few layers of tape on the edge until the later stages.

 

[Steve56]

Of course, you could also buy a properly made razor that doesn’t need the spine to be thinned. Just sayin’.

 

[rbscebu]

....
As for the shave, it has been a while. I recall that it felt much more like my angle, but it didn't change things enough to overcome my annoyance with the heavy, floppily-attached scales. So I put the razor aside and thought of other things. Probably time for me to break it out again and give it a spin.

It is fairly easy to tighten up the scales at the pivot pin. Give it a go and it might solve your problem.

 

[rbscebu]

+1 for the Atoma diamond plate. A few layers of tape on the edge until the later stages.

I would if I could but that would set me back well over USD 100. For the amount of use it would get, I would rather put that money towards something more useful.

 

[rbscebu]

Of course, you could also buy a properly made razor that doesn’t need the spine to be thinned. Just sayin’.

I have found that SR's with bevel angles around the 18° to 18.5° mark are more forgiving yet still shave well. They are my recommendation for n00bies to the art.

The reason for ordering and wanting to thin a Titan ACRM-2 T.H.60 down is to see how it shaves with a more accute bevel angle. If it works out well with the T.H.60 (cheap), I might then have a go with a T.H.64 (costs twice as much), although that is already at a little under 18°.

Most of the Chinese and Taiwanese SR's have a more obtuse bevel angle compared to western made SR's. Asians, their main market, prefer them that way. I'm not sure if it is because they want something more forgiving or if it is because of the longer edge retention time between refreshed.

 

[DrStrange]

I would if I could but that would set me back well over USD 100. For the amount of use it would get, I would rather put that money towards something more useful.

Gordon, 4-Sided Diamond Hone Block​

US $12

 

[rbscebu]

Thank you @DrStrange. Your post prompted me to look for other diamond plates. I found on eBay what I think will be suitable, set of three for USD 7 including delivery from Sydney.

​

Grit sizes are 300, 400 and 600. Each plate is 51mm x 153mm. They only have to last this one project and I'll be happy at that price.

 

[APBinNCA]

I got a dual sided 400/1000 off Amazon for lapping. I wish I had seen you mention the bevel angle of the Titans as I have SEVERAL coming and I am not sure how I feel about this news. I am having enough trouble with a razor that has a 17.5 degree bevel. At least I have weeks or months before they show up...

 

[rbscebu]

I have measured the bevel angle at mid edge length of a few of my SR's. They are:

S.K. Colling Custom = 16.5°​

Ralf Aust 6/8 = 16.3°​

*Gold Dollar W59 = 15.8° & 17.5° (modified)​

*Gold Dollar 208 = 19.5°​

Revisor 6-0035 = 16.9°​

G. Butler Shakespeare = 17.4°​

Puma 1⅝ = 16.8°​

Cadman Bengall 5/8 = 16.1°, 17.1°, 17.5° & 17.4°​

Cadman Bengall 6/8 = 16.0°, 16.9° 15.7°​

*Titan T.H.60 = 18.8° & 19.6°​

*Titan T.H.63 = 18.8°​

*Titan T.H.64 = 19.1°​

*Titan T.H.70 = 18.6°, 19.0°, 18.0°, 19.7°, 18.4°, 19.7° & 18.6°​

Obviously the Asian (*) market is preferring more obtuse bevel angles by about 2°. I'm not sure if @Slash McCoy has some figures for other Gold Dollar models.

All of my SR's have been honed up and are maintained to my high standard of shave-ready. I have found that the Asian made SR's shave just as well as the European made SR's. The Asian made require just a little more pressure tangential to the skin to slice through the whiskers. This is noticed particularly in the fool's pass, my standard edge test that is performed daily. They all shave comfortably and just as closely. I would say that bevel angle is more important if the edge is not as keen as it should be.

 

[DrStrange]

Thank you @DrStrange. Your post prompted me to look for other diamond plates. I found on eBay what I think will be suitable, set of three for USD 7 including delivery from Sydney.

View attachment 1448497
​

Grit sizes are 300, 400 and 600. Each plate is 51mm x 153mm. They only have to last this one project and I'll be happy at that price.

You're welcome.
When I use diamonds, I go high speed and low pressure.
I think that removes the most steel for the least amount of hone wear.

 

[Bevel]

I am having enough trouble with a razor that has a 17.5 degree bevel. At least I have weeks or months before they show up...

If you're having trouble with a 17.5 degree bevel, which is bang in the sweet spot, then your bevel is not set correctly.

I have measured the bevel angle at mid edge length of a few of my SR's. They are:

Obviously the Asian (*) market is preferring more obtuse bevel angles by about 2°. I'm not sure if @Slash McCoy has some figures for other Gold Dollar models.

On the Asian bevel angles being wider I suppose asian beards aren't as tough and a lot are whispy enough where 20° is fine. That being said my Kamisori (obviously Asian) has a bevel angle of just over 15° and joins 3 other sub 16 razors all European.

As others have said tape the edge which has the dual effect of protecting the original edge until you're ready to actually hone it and, as the edge isn't wearing, lessens the amount of spine to come off to achieve your desired angle. Use 3-4 layers and replace the top layer as required. If you have different colour tape end with black so it's immediately obvious when a tape change is required.

As a large amount of metal needs to come off relative to a regular honing use a carrier of some sort WD40, water whatever.
I'd use moderate pressure and take my time so that if it starts to go wrong I have plenty of time to react.
EG The one thing I'd worry about a bit is if/when the spine becomes thinner than the tang and both the tang and shoulders come into play. It'll totally change the look of the razor and not in a good way.
Because you're going to use a 51mm (2 inch) diamond plate you'll need to be particularly careful you don't mess up the geometry. If a 3 inch is available it would be much better. If it were me doing it, and I was taking my time anyway, I'd probably use your 400 grit Chinese synthetic if it's a 3" hone. 0.25mm shouldn't take that long on a 400 maybe 15 mins per side?

 

[Darth Scandalous]

Gordon, 4-Sided Diamond Hone Block​

US $12

View attachment 1448485

I have one of those. Had it for years, I think my brother gave it to me with a set of chisels. I have no idea if it's any good but I've used it on knives, used it to reprofile heels on razors, and even though it's small, used it to lap and flatten stones.

One thing I don't know is how well the diamonds are bonded. It's pretty broken in now but given the price I'd be nervous about using it to make slurry.

But for grinding off a lot of steel, it's kind of pefect.

 

[DrStrange]

This Primus was a square point with a chip near the toe when I got it.
I used the diamond honing block.
I did it dry.
I held the blade like I was scribbling with a pencil so it never got hot.

https://www.badgerandblade.com/forum/attachments/dscn0930b-jpg.1098421/