Is this too much hone wear to start working on?

[drmatt357]

Yet another great post Slash. Thanx. I just bought a 4X36 belt sander to help me with this.

 

[Heespharm]

Yeah if it is a #66 then it has about a 19 degree bevel angle if the spine was not thinned significantly. However, most users find that it will shave fairly well anyways, but remember that with a big bevel angle, you cannot afford any convexity in the blade. That means you should be honing on synthetic stones and washing off any slurry that develops, or honing on lapping film. Slurried naturals might work depending on your stones and your technique but a clean synth progression would be better. Again, due to the large bevel angle, you can and should go very fine on the finish, and minimize the use of pastes post-finish. Fat bevel angles will support very fine finishes at the edge. With that big of an angle, you should never find the edge to be particularly harsh. Anyway, try it next time you hone it up. Myself I like how they shave at around 16-1/2 degrees but there are plenty of guys out there shaving with them basically unmodified except for a little heel work. See Buca's for an example of that.

However, I would urge you to try thinning the spine on a couple. Best way is to glue sandpaper to a polished marble tile and just set the bevel at about 80 grit honing flat with no rocking, no x stroke, just hone flat, and well, hope you like a straight edge cause that is what you are gonna get. At first use moderate pressure and watch the edge. The toe and maybe the new heel (before doing this, you should do your heel cutaway and totally smooth away the shoulder) will be last to develop a bevel of course. Once you have a bevel over at least most of the edge, start applying pressure more to the spine. When the edge bevel is nearly complete, TAPE THE EDGE. You will have to refresh the tape often. The taped edge essentially becomes your bevel guide for thinning the spine, and the spine and edge remain in line with each other. The original spine is often very inconsistent so the width of the contact area will vary. Not to worry. You are creating straightness where there was none.

It helps if you also thin the tang so you do not form a new shoulder. Makes things easier and keeps it looking nice. As a bonus you will be getting rid of the stamping. When you are done, it won't be a Gold Dollar any more anyway, so no need to carry the brand.

As you thin the spine, monitor your bevel angle. Shoot for around 17 degrees for your first batch. That's a nice Steady Eddie angle that will have nice cutting ability but not be tricky to hone or ever be particularly prone to harshness.

After you have your new bevel angle set, round off the edges of the spine's bevel flat. Get it nice and round again. You are almost there. Remember, you left the tip of the toe and heel without a bevel. So move up to maybe 150 grit and then 220 grit as you hone some more. Keep going until your bevel is fully formed at the toe and heel. Then once again, round your spine back down. Your blade is done, in form anyway, if not in finish. From here it is all hand sanding to smooth and prettify it and get rid of the original factory grind marks. Watch out... that edge will CUT YOU. Work with your hand around the spine, never with the edge facing the web of your hand. Pinch the blade between folds of small pieces of sandpaper. You can try to hurry this up with a dremel but your first several tries will probably have you digging even deeper grind marks than what you are trying to eradicate. And hand sanding is a slow job. Doing it right takes DAYS. The first grit you use needs to remove ALL original digs and scratches. You must not leave anything for the next grit except maybe a little in the thin part of the blade, where you may need to minimize material removed. The next stage removes all of the scratches from the FIRST grit, completely and totally. Leave nothing at all for the next grit to get or you will be sorry. Then the NEXT grit removes all the scratches left by the first. Each grit removes all of the scratches of the previous grit and replaces them with its own finer scratches. Work up to at LEAST 1k grit paper and I prefer to go up to 2500 grit. From there you can go to diamond paste. 3u, 1u, .5u, .25u, .1u and you end up with a beautiful mirror finish if you did everything right. For the diamond, you can use a dremel and a felt wheel. For the finest grits I like to finish up with a cloth wheel. Finally, the last grit should be done by hand with a piece of old t-shirt.

Now set your bevel at 1k, and look at your spine again. You may want to sand and polish the spine yet another time. YMMV. Then run your progression and finish on your edge and you have turned your $3 razor into a $200 razor, assuming you also rescaled. Unfortunately you used probably $10 worth of abrasives and $500 worth of labor to do it, but you did it and wow... how nice.

You will mess up. So don't get just one or two. Get 10 or 20. Do a batch of them. Especially when grinding with power tools, such as the heel cutaway and the shoulder fairing, you only want to grind for a few seconds then let it cool. So it is more efficient to do several, picking up each in turn and letting it cool as you run through the others, then the first is ready for some more grinding. I don't like to dunk in water, myself but other guys do it. If half of your first batch survives the process, you are doing pretty good. You end up with a couple for shaving, a couple for PIFing, and maybe pick the best one of the bunch to sell on BST. Lotsa fun. End up with great razors. Turn other guys on to great razors. Spread the GD love. What's not to like?

Wow very detailed post... Thanks

 

[Slash McCoy]

Yet another great post Slash. Thanx. I just bought a 4X36 belt sander to help me with this.

Wow... sweet. This is an upright type and not a floor sander, right? Can you get in close to a contact wheel from both sides? Anyway the bigger belt will run cooler and give you a few more seconds of grinding before you need to let the piece cool. I only have a 3x21 floor sander, Harbor Freight's knockoff of the B&D Dragster. I like the small front roller. And it is not shrouded so much that I can't get the razor onto it from both sides.

www.supergrit.com I have found to be a good source for paper and for belts, especially in finer grits. You will want some fine belts, yeah. 600 or 800 grit. They really help. Be careful and don't burn your razors!

 

[drmatt357]

... but remember that with a big bevel angle, you cannot afford any convexity in the blade. That means you should be honing on synthetic stones and washing off any slurry that develops, or honing on lapping film. Slurried naturals might work depending on your stones and your technique but a clean synth progression would be better. Again, due to the large bevel angle, you can and should go very fine on the finish, and minimize the use of pastes post-finish. Fat bevel angles will support very fine finishes at the edge. With that big of an angle, you should never find the edge to be particularly harsh. Anyway, try it next time you hone it up.

Please explain this some more Slash. Where is the convexity you speak of?
I have discovered something like this but until now, didn't associate it with the bevel. I thought it was the metallurgy. I have proof of what it looks like under the microscope but misunderstood the result.

 

[Slash McCoy]

Please explain this some more Slash. Where is the convexity you speak of?
I have discovered something like this but until now, didn't associate it with the bevel. I thought it was the metallurgy. I have proof of what it looks like under the microscope but misunderstood the result.

Convexity of the bevel, particularly at the very edge. A slightly convexed edge behaves as if it has shoulders or buffers that stand the edge off from the skin a small amount, probably on the order of a fraction of a micron. Reduces cuts and abrasion but also can reduce cutting ability slightly, when it is extreme. The absolute edge will have a bigger bevel angle than the geometrical overall bevel angle of the blade. The causes are varied but it can result from stropping on a pasted hanging strop, honing on film over multiple layers of damp paper, stropping on pasted balsa with pressure or with a coating of paste, honing on a heavy slurry, etc etc etc, to be a little bit less than scientifically precise. I am probably not the best person to ask about this so I hope one of the other guys will chime in. And from my own perspective, since I have not examined presumably convexed edges under a microscope, it is all theoretical, based on the apparent results of the shave. I can't point at the smoking gun. All I can do is round up the obvious suspects.

This same minute degree of convexity on a blade with a very acute bevel angle can be welcome, an improvement on the shave quality, reducing harshness and making a more robust edge. Sort of like a very subtle, well executed microbevel. The difference is in the size of the base bevel angle.

At any rate, if you hone a Gold Dollar having the original bevel angle by different methods, you will most likely see the predictable differences in the shave. A honing method that would probably feel harsh on most blades, such as finishing on film without paper, or a very fine synthetic, will give a pretty fair shave on the GD66. A finishing method that gives a smooth but still sharp edge on most other razors, such as a coticule edge finishing with very diluted slurry, might give an edge on the GD that does not cut whiskers quite as eagerly as a synthetic edge. No need to take my word for that. Give it a try, on one of those 19 degree GD66's.

 

[drmatt357]

I get that the 19 degree won't shave as well as a 17. I'm still confused with the convexity. It sounds as if you're saying the edge bows to one side or the other. If that is what your saying then there would have to be a concurrent concavity on the opposite side... No?

What I saw under the scope was not geometry issues but what I found as a tell tale sign of a blown edge on a coticule. It didn't happen on synthetics and not on all GDs. I recently realized it was the 19,20 and 21+ bevel angles.

 

[Slash McCoy]

No not to one side... to both sides. Imagine honing freehand, varying the honing angle slightly from stroke to stroke. Now imagine the same effect but far more subtle.

 

[Oscroft]

Yeah if it is a #66 then it has about a 19 degree bevel angle if the spine was not thinned significantly. However, most users find that it will shave fairly well anyways, but remember that with a big bevel angle, you cannot afford any convexity in the blade. That means you should be honing on synthetic stones and washing off any slurry that develops, or honing on lapping film. Slurried naturals might work depending on your stones and your technique but a clean synth progression would be better. Again, due to the large bevel angle, you can and should go very fine on the finish, and minimize the use of pastes post-finish. Fat bevel angles will support very fine finishes at the edge. With that big of an angle, you should never find the edge to be particularly harsh. Anyway, try it next time you hone it up. Myself I like how they shave at around 16-1/2 degrees but there are plenty of guys out there shaving with them basically unmodified except for a little heel work. See Buca's for an example of that.

Ah, now that's interesting. I recently honed a Titan razor, which seems to have the same geometry as a GD (I'd put money on their being made in the same machinery just with different steel and fancier finishing), using a Naniwa progression to 12k plus a lather stage, and it shaved surprisingly smoothly.

I hadn't thought about the bevel angle.