Coarse grit sharpening?

[sam]

Years ago I remember Alexandre Sidorov talking about switching to a coarse grit sharpening from his usual high polish sharpening, and finding that it extended the life of the graver. I also think Sam Welch might have agreed on that and used something similar. I wish I could find that old thread but I can't.

I've been sharpening to 1200 grit for several years with the exception of polished gravers for brightcutting precious metals, and 1200 suits me quite well and I feel I get good life from my gravers, although I'm not cutting much super hard stuff.

Comments?

 

[dcurrie911]

The other day I tried 600 grit on the heel of a bulino tip. I use the Lindsey templates so the Method I used was to push foward on the 600 grit stone so that the ’Micro-grooves’ Set into the heel would be parallel with the Direction of cut. Something like a serrated edge. Too soon to give meaningful feedback on the longevity but curious what others contribute. Are you suggesting coarser yet?

Dan

 

[monk]

if that is the case, it would be an intresting read. i wonder what he considered, "rough sarpening"? by that i mean what grit did he consider to be rough.

 

[SamW]

I don't remember that Sam. I have for many years used 600 for the face and 1200 for the heel. The face on a power hone and the heels by hand similar to Lynton in his video...just a quick swipe across the wheel sliding across a tool blank to maintain a lift angle.

 

[Matthew Evans]

.

 

[mitch]

I've been using 1800 for some years now, but also switched to a carbide 120 graver about the same time, so that certainly had an effect on point life, too. The prevailing wisdom is that a higher polish leaves fewer incipient failure points for a crack or fissure to get started. I wonder what point geometry he's using that rougher sharpening seems to improve?

 

[simone-cervellati]

i stop at 2000 for basically everything, break any burrs by stabbing a piece of hardwood a few times and then i strop face and heel on a piece of leather with a bit of metal polishing paste on it, usually that's more than enough even for bright cutting.
my hunch is that the stress point is not actually the tip but the point where the heel and belly faces meet, stropping rounds that "inverted pyramid" point and the ridge where the heels meet. i find that that kind of action actually improves the longevity of the tip.

Also, frequent stropping (say every 10/15 minutes of cutting or whenever you start to see the quality of the cut degrade) usually lenghtens the life of the point even more.

for non parallel heeled gravers (think onglettes, flats and rounds with no heel) i usually cut a very tiny facet on the face of the graver , 10 to 15 degrees steeper than the face. and i mean tiny, usually just 0.2 to 0.5 mm in height. that improves the life of the graver, especially when working with onglettes since it strenghtens the tip and makes cutting much more easy.

Again this is a hunch, but i think it invoves the way your pushing force is directed while cutting, my general sensation is that heeled flats always require more force to push trough the same cut when compared with non heeled ones.

just my 2 cents on the matter. hope it makes sense

P.S. spending a few weeks learning to hand sharpen quicly and efficiently, and detaching from the usual 120°, v shaped, parallel heel graver can be a godsend, and it's something that often gets neglected beacuse of the aformentioned 120° versatility. but it lends to a lot of easy and fast experimentation on the fly.

Stay SHARP guys
Simone.

 

[sam]

I don't remember that Sam. I have for many years used 600 for the face and 1200 for the heel. The face on a power hone and the heels by hand similar to Lynton in his video...just a quick swipe across the wheel sliding across a tool blank to maintain a lift angle.

I vaguely remember Sam, and it must have been you that got me using 600 face/1200 heel as well, because that's all I've used for a very long time.

I found this in an email from 2013 from one of my GRS colleagues that worked with Alexandre at a show in Switzerland.

"About the C-Max left in the “satin” finished condition which I believe is what Alexandr calls it. He absolutely swears it extends life over mirror polish when working on stainless watches. For the life of me, I cannot explain this yet. I have learned that what Sidorov tells me can almost always be taken to the bank. He is very savvy with tools….I think it’s both his thing which he loves plus a natural intuition."

There you have it, for what it's worth.

 

[Mike Dubber]

I complete my final grinds on the 1200 wheel with the GRS APEX system - and that wheel stays on my Power Hone until I need to make a new graver.

After a clean up grind accross the bias of the graver face, I make six light strokes on the both reliefs without power. The final step is to brighten the reliefs on leather. I strop the reliefs on a 3"x 6" bock of wood with apiece of leather glued to the surface. I spray the leather pad occasionally with 50,000 Mesh Diamond Spray (weekly +-) and use it dry. The stropping is done on the diamond laden leather pad by placing the reliefs on the pad and pulling backward - three stokes on each flat. Note: I've never owned a ceramic or cast iron wheel.

I've been doing this for the past 20 years with great success. My theory is that while the stropping action polishes the flats bright, it also slightly softens the very sharp angles and makes the graver less prone to breaks and fractures. The last thing I do is a quick dub on the point, and it's back to cutting.

 

[papart1]

a quick dub on any and all burins Mike?

 

[SamW]

That's why he is called...Dub ber

 

[Mike Dubber]

Yes, more or less.

I do the same with all my Speitzer (or Onglette) points, except I pull and roll from one side to the otheras I pull the graver backward over the leather strop. Attached are three examples of the resulting bright or flare cuts - 2 on demo plartes that I cut during my class last week and another of some letters cut with flare cut.

 

[rmgreen]

This thread has been a super informative thread. I am a bit confused by Mr. Dub ber's comments. There is no mention of "heel" only "reliefs". I am assuming that the heel is done with the 1200 at something close to the 15deg angle and that the relief is somewhere between 5 and 10degs or am I more confused than I thought?

 

[Mike Dubber]

Yes Sam - is it DUBBBBING - but Dub doesn't do Flare as well as the other SAM.

It difficult to keep up with which is Sam is which is SAM................

All of you should buy SAM's Fare Cut video......does that clear it up?

 

[Mike Dubber]

OK, "Heel" if you want - and I use a 50 degree face with a 17 -1/2 degree relief/heel.

That's OK RM, I spent the first fifteen years at this art without talking with another engraver - no Forum, no books...no Power Hone...no sharpening devices - hammers and chisels...talk about confused!@X#@

 

[pmace]

Aw man! I was just getting good at resharpening a broken point and getting a 50k grit mirror polish on everything in less than 20 minutes. I was going to be a millionaire selling my special diamond polishing elixir. What do I do with a lifetime supply of diamond powder? I wonder if it would be any good in toothpaste?

 

[Matthew Evans]

Aw man! I was just getting good at resharpening a broken point and getting a 50k grit mirror polish on everything in less than 20 minutes. I was going to be a millionaire selling my special diamond polishing elixir. What do I do with a lifetime supply of diamond powder? I wonder if it would be any good in toothpaste?

I hear it makes really good tv screen polish, please send pictures if it works.

 

[Chujybear]

I remember the thread..
I couldn’t get past the same logical issue Mitch has.. but there were a lot of guys saying 600 (is what i remember)

 

[dlilazteca]

Sam if I remember correctly it was the other Sam that might have mentioned something to the sorts and I've stuck to it ever since I only go to 600 grit to work on firearms stainless no problem

 

[mdengraver]

As long as the engraver has true grit they will succeed!