Why ???

atexascowboy2011 · Sep 13, 2015

Why, when cutting steel, stainless, etc. were some of us trained to put say a 55Â° face on a graver then finish it off with an 80-90Â° face (NOT including the heel), instead of skipping the 55Â° and going straight to the 80-90Â°.
Granted the old H&C masters did all of their sharpening by hand, eliminating precise angles.

The saying that today's precision sharpening has produced better quality of work doesn't hold water as there are very few engravers today who are capable of cutting the Angel hair lines that Hendricks cut with a H&C !

Before folks go off on a tangent, my question still is, Why put a 50Â° or so face on a graver then finish it with an 80-90Â° cutting face (NOT including the heel) instead of going directly to the 80-90Â°?

Sam · Sep 13, 2015

I've never heard of finishing off the face of a graver at 80-90Â°.

atexascowboy2011 · Sep 13, 2015

You've never heard of DUBBING a graver point ??? :shock:

Donny · Sep 13, 2015

I guess Dubbing could be 80-90 but it isn't a "face" as much as a ever so slightly dulling/blunting of the tip... at least thats how I've treated it when using it...

Donny

Sam · Sep 13, 2015

Oh, dubbing. Yes. I just take the tip off.

Southern Custom · Sep 13, 2015

Also when dubbing a tip, the angle may be 90 deg. but it's only a very tiny amount on the tip. Not really a face at all. The 55deg face is still doing the cutting after that dubbed point slips below the surface. I can't imagine cutting with a 90 deg face would get you very far!
Layne

atexascowboy2011 · Sep 13, 2015

Okay, by taking the tip "Off" you do not change the cutting face angle ?
Answer- Yes you do.

I was just looking again at Turpin's book and saw two of Erich Boessler's gravers.
The small pictures make it very hard to see, but it appears that he came with a very long face (roughly 2") at around a 30Â° slope or what we call a face.
This is the same as I also remember Terry Theiss' gravers as it always amazed me that Terry was able to keep from shearing his tips off during some of his sculpting which often times exceeded 60,000thds in depth.
But, then again, Terry always finished his gravers off to an 80-85Â° cutting edge/tip/point.

atexascowboy2011 · Sep 13, 2015

Layne, you just said that the face IS changed to a 90Â° face and I agree that the cutting edge past the 90 is a lower angle but still, the primary cutting face has been altered to 80-90Â°.

LVVP · Sep 13, 2015

Could you put some pictures for more understanding, please

atexascowboy2011 · Sep 13, 2015

Vlad, as I told you in that other thread, my phone capabilities do not allow me to post pictures.Maybe tomorrow some one else can furnish pictures.
Tira gave her rendition of how she dubs the point as did I in that other thread.

1- Sharpen your graver as you normally would.
2- Hold the graver similar to a pencil on paper, with the belly facing away from you, but at an angle of 80-85 degrees to the hard Ruby Stone.
3- Pull the graver towards you for roughly 2&1/2", two times.

That is it !
You have now stoned the face back changing it to an 80-85Â° cutting face.
As I said before, DO NOT OVER THINK THIS !
Just guessing, I would think the stoning makes roughly a 30,000thnds tall cutting face.
Here again I'm guessing most of your primary cuts are in the neighborhood of 5-6,000thnds deep.
To cut past that 30,000thnds face with one pass would be really tough !

dhall · Sep 13, 2015

This is an interesting question. I think part of the answer might be that, yes, you are changing part of the cutting face, but that since you are taking a cut larger than the dubbed face by itself, you are actually employing a compound angle to do the cutting. If you could somehow take a cut that only had the dubbed edge removing metal, then your effective cutting face angle would be in the 90 degree range. Since our cuts include the dubbed angle, as well as the originally sharpened face and heel angles, the compound cutting angle is doing what it should - giving added strength via the "dub", and conventional cutting clearances with the face and heel angles. Compound cutting angles have been in use in various industries for cutting exotic materials for a while, e.g. aerospace. Dubbing is simply a "get'r done" approach that was noodled out, probably by several folks at different times (based on "trade secrets" that, I'm sure, went to the grave with some), then trial and error led to its re-adoption, and in our current times, broadly disseminated this information. Another way to think of this might be that it is the face/heel edge without the dub that actually does the cutting, and the dubbed area provides the strength so the face/heel edge can hold up to do its job.

I don't think I can really agree that the dubbing is "30,000thnds". Maybe I'm reading this wrong, but .03125 = 1/32", or 1/32" is between 31 and 32 thousandths of an inch. I don't think anyone dubs their points this much. Also a guess, but that's a pretty large dub. My perception is that virtually everyone who uses a dubbed point is making a cut that is larger than the dub by itself, based on the rather subtle stoning that makes such a big difference in the ability of a given graver to withstand fracturing to which it had previously succumbed.

Best regards,
Doug

Southern Custom · Sep 13, 2015

To get a frame of reference, 30mil is about the thickness of a credit card. I cannot see my dubbed point with the naked eye. It takes a microscope. Whereas cutting to the thickness of a credit card is not difficult. I would imagine I regularly cut to 1/3 the thickness of a credit card. Or 10mil. I don't know how tall my dubbed point is but I can assure you it's not 10mil. And certainly not 30mil. I have gravers with a face that's 30mil or less.
In addition, Tira gives very different rendition from what you mentioned of how she dubs a tip. In fact using the exact method I do.
"I hold the tip of the graver straight up and down (90 degree style) and trace an X and O very lightly on the ceramic lap charged with the diamond spray."
When I do this there is almost zero pressure on the graver. I make a small x or w or whatever the heck happens in the space of 3 or 4mm.
I think many new engravers over think this stuff but I'm sure it's the result of not getting the desired outcome or thinking there's some magic angle. I cut for years with whatever angle I happened to whip out by eye for the day. The magic ain't in the tool.
Layne

Phil Coggan · Sep 14, 2015

Too much attention and time spent on angles, heels, templates etc, ok, templates give you dead accurate angles, I worked for nearly thirty years before I even saw a template, most of my pictures here up until a couple of years ago are H&C and push...45/50.60/70 or 80 deg...who knows

I have to say though that for beginners templates are good because a lot of time is needed to learn hand sharpening!

Phil

Sam · Sep 14, 2015

Phil Coggan said:
Too much attention and time spent on angles, heels, templates etc, ok, templates give you dead accurate angles, I worked for nearly thirty years before I even saw a template, most of my pictures here up until a couple of years ago are H&C and push...45/50.60/70 or 80 deg...who knows
I have to say though that for beginners templates are good because a lot of time is needed to learn hand sharpening!

Phil

Thank you Phil. My thoughts exactly on the subject dubbing the point. IMHO it's too much unnecessary analysis on something as simple as removing the point of a graver to strengthen it. I've seen Churchill do it by simply swiping the point on a stone.

bram ramon · Sep 14, 2015

Lol I can't imagine engraving anything with a 80Â°/90Â° face.. you simply won't be able to see your tip of the graver.. I maximum go for a 50Â° face and never have any problems and my work is 90% taught austenitic stainless.. you have to remember the steeper the more pressure on the point the more it's plowing instead of cutting

Addertooth · Sep 14, 2015

I know less than nothing about engraving, however, I did work as a machinist for several years, and even carried the MOS (skill category) in the military. For working on a metal lathe our tool tips were frequently "dubbed". It achieved two things:
1. Tip durability was dramatically improved.
2. The sudden change in direction of the removed metal of the worked piece (the chip or string) would get micro fractured from the steeper dubbed edge making the removed metal more manageable (the removed metal strip could be broken away from the tool more easily due to these micro cracks, and therefor more manageable). Metals which were "chewy" required more of a dub than metals which had less elasticity. Some varieties of stainless were very chewy.

jerrywh · Sep 14, 2015

I'm with Sam. I never heard of that before. I don't see any way you can cut anything with a 90Â° face. It won't even stay in the metal.

Keirkof · Sep 14, 2015

I wouldn't be surprised if an 80-90 degree angle is what is actually doing the work, possibly with hardly anyone realising it. I've heard the advice to use really steep angles when doing deep engraving (for stonesetting) on hard metals. And why we sharpen to lesser angles for the face? Well, it does help a lot with visibility. It also gives the splinter of metal somewhere to go to, and that may be a very important factor too...

SamW · Sep 14, 2015

If it works, don't "fix" it.

atexascowboy2011 · Sep 14, 2015

This thread's responses reminds of sitting in history class as a kid and hearing how centuries ago the general consensus was that "The world is flat."

Why ???

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