What Degree's For Fine Shading?

[ChrisB]

I have Tried all the Degrees, 120, 110, 90, 70.
I polished the Graver Point, But Still Don't get Crisp sides, The Material is 430 st/st, It is Quit Gummy,
My Face is 50deg, Even tried stubbing it.

Please Any Help!!!!

 

[Sam]

Chris: I use a 120 with a 45° face and 15° heel for nearly all metals. If i need more strength, I might change the face to 50°. / ~Sam

 

[Weldon47]

Chris,

You are probably already doing this but if not you might try a lubricant. As you are already aware, stainless "galls" instead of cutting smoothly and a lubricant will help provided your tools are correctly sharpened. I sharpen my tools the same for either carbon or stainless but find (even though I use a hammer & chisel) lubrication makes a lot of difference in the quality of the cut. The results are most apparent on difficult to machine materials like stainless steel.

hope that helps & keep at it,

Weldon

 

[Glenn]

Chris, you might call and industrial supply house to see if they stock specific lubricants for cutting stainless. In the machine shop business this is common.

 

[Thierry Duguet]

If I may say so. I think that polishing you tool is not such a great idea if you want to create a shadow, you want your line to absorb "break" the light not reflect it, by polishing your tools you create a polish cut which is more likely to reflect light. Further more your unpolished cut is more likely to retain dust and dirt and will become even darker with time
A fine shading required only a very sharp tool regardless of the angle, as your tool get doll, the bottom of the cut become rounder and start to reflect light toward the viewer.

 

[Ron Smith]

Thierry, I think this comes from the jewelry and bright cut approach. I teach the same thing that you do, but to add another "theory" to your statements, the narrower tool also keeps the llight in the cut instead of reflecting it back into your face. More sharpening is required as the points are more delicate, but for Bulino work it will slightly enhance your intensity and is worth it to me. I hear the advantage to polishing the tool is in using carbide particularly due to the grain of the carbide and the polishing is supposed to minimize chipping. I have resisted carbide for this reason, but you can't even afford a microscopic chip when using a hand pushed burin. The pneumatic tool overcomes this problem and will cut regardless, but that has to do with the heavier work. It is still important to have the tool sharp for fine line work. I leave the stone finish on my tools for the very reason you described......of course you can kill shine by other means also....... Good information!..........Ron S

 

[KSnyder]

Weldon, stainless does cut. 416 will look like sterling if tools are on center & feed at the proper speed. I've machined tons of it making ignitors for F-18's etc. It does need lubricant. Mostly water soluable oil is what we used. At home for engraving I use tap magic & Jergens tool aid mixed together.
It( stainless & other steel) usually can gall if the tool is dull and/ or high or low in the cut. If the tool is dull it tends to drag leaving a fuzzy mark that will look rough sanded on a big piece.
As an aside , cheap stainless, that is to say stainless with a less than standard composition mostly from foreign countries may not be easy to cut & have inclusions etc.
Kent

 

[chris]

fine line shadeing

hi
chris
im of the track a bit but while they were talking about polished graver in chris decamillises fega dvd he said they use a highly polished graver to produce the darkest shade lines they can get wouldent this apply for shadeing your normal engraveing or just banknote
chris

 

[Weldon47]

Kent,

Thanks, I'm aware that stainless does cut! I don't particularly like it much, though. My experience with it has been over the last 28 years most frequently on S&W's and knives. I use a hammer & chisel 99.9% of the time (currently) so I probably feel it more than if I used air tools exclusively.
Thank you,

I believe as you point out and as was the intention of my original post "lubrication is the key"

Keep chipping,
Weldon

 

[Thierry Duguet]

hi
chris
im of the track a bit but while they were talking about polished graver in chris decamillises fega dvd he said they use a highly polished graver to produce the darkest shade lines they can get wouldent this apply for shadeing your normal engraveing or just banknote
chris

I think that anyone who pretend that polishing graver produce dark shading obviously does not know what he or she is speaking about and did spend very little time thinking about it. Do you polish a barrel to keep it from reflecting light or do you rust blue it?
One polish tool for two main reasons, to create bright cut and to diminish fracture point in the tool. One create a dark line by creating a angle of refraction which is as obtuse as possible, if the light is reflect toward the viewer you have a "bright" cut, if it is not you have a dark cut, it is a very simple optic phenomena. A non polish tool create a large number of microscopic angles reflecting light in a large number of direction, it make the cut appear darker because less light is reflected toward the viewer, a sharper angle tool will also create darker line for the same reason (less light is reflected toward the viewer).
One need to understand what one is doing, your line is not dark or bright, a cut is not a pencil line, it does not "absorb" light, it reflect it, all of it. When one engrave one play with light. The cut line reflect light as diamond do (but with the opposite purpose), what you are seeing when you look at engraving are projected shadows (a shadow is just a lesser amount of light being reflected), as the amount of light reflected toward you diminish the shadow become darker. That angle which reflect the light is call refraction, every material has a different one including air and water, that is why when you look at water under a certain angle it act as a mirror and why star are not physically where they appear to be with your naked eyes (refringence).
Chris Decamillises may get very dark line with a polish tool but it is due to his angle of his cutting tool not to the fact that the tool is polish. Should he say otherwise he would contradict the laws of physic. Of course you should not take my word for it, go see a physic teacher, he shall explain optical laws better than I can. One last thing the principle that I just try to explain apply to all type of engraving including a scratch made with a nail on a polish surface.

 

[Mike Cirelli]

As I read through this thread, my thoughts on it are. As long as you have two different contrasts e.g. satin surface with a polished graver, or polished surface with a satin graver, or satin on satin as long as one is courser than the other you will get a contrast with an illusion of black. The narrow graver cut would bounce the light back and forth in the cut much more than a wide graver cut. If that's the case the narrow cut would appear darker and the wide would appear more of a flash. In either case if the right surface preparation is applied either one could appear dark. Just my thoughts.

 

[chris]

sorry
thierry
you sound a bit upset over the question want ask ever again
chris

 

[Sam]

When I first heard Chris DeCamillis' claim that bulino engraving appears darker with brightly polished gravers, I was quite surprised. I thought just the opposite. After doing a bit of testing I had to agree, since the bright lines appeared darker than those cut with an unpolished graver. I know nothing of physics, but I've been mentioning this to my classes for the past 2 or 3 years now, and quite often my class demonstrations with a brighly polished graver render darker lines than with my unpolished tools. Just food for thought. Your mileage my vary.

Cafe cheers / ~Sam

 

[Thierry Duguet]

sorry
thierry
you sound a bit upset over the question want ask ever again
chris

No, I am not upset, just French, my use of the English language is often very literal. I am sorry if I did hurt your feeling.

 

[KCSteve]

Sam

Perhaps the polished graver gives a cleaner line that, when fine enough, is only bright on a very narrow angle of incidence where the unpolished tool gives a more ragged cut with lots of little facets and a greater chance that some will be reflecting light at any particular viewing angle.

This would be consistent with the physics. At the 'proper' viewing angle for the polished bright cut it will be much brighter than the rough cut, but I can see the rough cut being brighter over most viewing angles than the polished cut.

Next time you're doing the demo (or just fiddling about) you might try s l o w l y tilting a piece with fine dark lines to see if there's an angle where they light up. It should be there but I'll bet it's hard to hit.

 

[coincutter]

This is gettingto be an old thread but what the heck

It makes a big differnce in which way you orientate the graver when polished. If you polish at the same angle as you sharpen - ie on a rotation you get a nice smooth finish with striations. If in doubt put your graver under a high power scope and see if your "polish" leaves lines.

Optics of refraction apply - try to take a picture of chrome or a highly polished coin. You get black. Highly polished narrow channels cancel each other out, hence dark. With striations you are seeingthe light bounce internally from them. Since there are many they add up to a visual change.

 

[Ray Cover]

Chris B.

TO answer your question, for fine line shading generally I use a 70 degree belly with a 55 degree face and a 15 degree heel. In 416, 410, CP ti and 3al4v ti (the metals I cut the most) and most similar metals it does just fine. I don't know that I have cut 430 specifically but I don't see any reason this same graver should not work unless 430 just has something nasty in it as part of the alloy.

Hardness may have an effect as well. Most of the 400 series stainless has to be heat treated to take best advantage of its rust resistant properties. In some shapes and sizes it is standard practice to sell them already heat treated depending on what the end use is intended to be when the mill makes the stuff.

I am working on a SAA now and most of the shading on it I have done with a 90 except for the hammer. I found the hammer to be hard on this one and I have had to cut it with a 120. You can do fine line shading with any of the angles you mentioned but if you can get away with a narrower belly it is easier to get a finer line and control it (in my opinion).

Ray

 

[Lee]

When Chris told me about using a polished graver for darker lines my reaction was the same as Sam's. I tried it and it appears to me they are darker at least in most cases. Steve and coincutter may have the proper explanations. Not a light physicist but there is some logic to what they say. Keep in mind we are talking about angles typically 90 degrees or less judging from what most are saying they use for shading. Open up the angle and it may be a different story. The 120 may be enough more open that the bright cut effect is more evident. If paint or ink is going to be used it will really make no difference. The shine will be covered. Of late I have gone to a 120 for shading because of the opportunity to have great variation in the line width.