Diamond paste/powder

[pmace]

Anybody using diamond paste and/or powder and a copper lap for hand sharpening carbide gravers? I had some 1200 grit paste that I was using to polish embossing dies and thought I'd try it with an old copper practice plate as a lap with my Lindsay templates to see if it would sharpen a graver. It seems to me to cut much faster than my metal diamond plates. If you put it under the microscope you can see the little diamond particles stuck in the surface of the copper. I may try some 1/4 micron paste for the hell of it to see if it will polish the graver as well as the ceramic hone.

 

[monk]

how thick is the copper ? if too thin, you should back it up with a more rigid plate. not sure how copper would work. iuse the powdered diamond only on a leather pad affixed to a piece of hardwood. let us know how this works for you.

 

[pmace]

how thick is the copper ? if too thin, you should back it up with a more rigid plate. not sure how copper would work. iuse the powdered diamond only on a leather pad affixed to a piece of hardwood. let us know how this works for you.

1/16" copper plate backed up with steel plates to 1/2" thick to accommodate the Lindsay templates. I tried some 1200 grit powder in WD-40 and that did not work as well as the silicone grease that they use for the compound. I know gem stone cutters use copper, tin and zinc laps for polishing facets on their stones. I might try my cast iron lap too.

 

[tdelewis]

I think it would work. There was a post By Sam a few weeks back that showed how a cast iron lap works. I always questioned how can a cast Iron lap sharpen carbide gravers. Of course the cast iron doesn't. The diamond particles are imbedded in the cast iron. There is a video on GRS that shows the preparation you go through to get a cast iron lap ready to use. I would think it would be the same with copper. The lubricant used to prepare the lap may be an important factor. Check it out.

 

[sam]

Dry diamond powder on a cast iron lap sharpens carbide like a mirror.
GRS sells the diamond powder and the cast iron laps.

 

[pmace]

Dry diamond powder on a cast iron lap sharpens carbide like a mirror.
GRS sells the diamond powder and the cast iron laps.

Thanks Sam. I tried some on my cast iron lap this morning and it works like a charm. I don't have a Power Hone so I thought I'd try copper since it's easier to use with my templates. Gem cutters seem to like softer metals like copper, tin or zinc probably because cast iron is too hard. I just think it is amazing how cheap synthetic diamonds have become.

 

[rweigel]

I tried hand lapping on copper, soft iron and brass. Always used 0.5 micron diamond paste. Brass works best for me, actually a piece of lead free „Ecobrass“. I spread a little of the paste on the plate and rub it in with a piece of hardened steel.

A copper disc I made for the flexible shaft did not work at all, even after I made radial cuts with a liner to give the diamond paste some places to stay in. It celebrates a second life in my minihone (designed for 50mm diamond discs) where it polishes faces and heels. I guess the first attempts with the flexible shaft were twarted by the lack of precision.

My gravers are High Speed steel, not carbide, I should mention.

 

[pmace]

I managed to charge a copper practice plate with 3000 grit powder on one side and 50000 grit on the other. Using water as a lubricant they both polish a carbide graver face quite well. A different plate charged with 1200 grit powder does not do well at removing metal from the graver like a diamond stone. Neither works as well as a cast iron lap using a paste made of silicone grease and diamond powder (similar to a commercial diamond compound) by hand. I'm still experimenting with lap materials and compounds.

 

[DanM]

I managed to charge a copper practice plate with 3000 grit powder on one side and 50000 grit on the other. Using water as a lubricant they both polish a carbide graver face quite well. A different plate charged with 1200 grit powder does not do well at removing metal from the graver like a diamond stone. Neither works as well as a cast iron lap using a paste made of silicone grease and diamond powder (similar to a commercial diamond compound) by hand. I'm still experimenting with lap materials and compounds.

You can take a look at this link,people have been diamond charging copper laps for many years without problems .....https://usfacetersguild.org/using-copper-laps-to-cut-with-diamond/

Tool https://kingsleynorth.com/recharge-roller.html

 

[pmace]

You can take a look at this link,people have been diamond charging copper laps for many years without problems .....https://usfacetersguild.org/using-copper-laps-to-cut-with-diamond/

Tool https://kingsleynorth.com/recharge-roller.html

Dan, my point exactly. If a copper lap will cut gemstones one would think it would work on carbide gravers. I got the recharge rollers from Kingsley and use them to charge the laps. One thing I did not do is "score" the plates first. That may be part of the problem. Another is that I annealed the plates to make them softer. I may try again with the 1/2-hard original stock and see how that works.

 

[DanM]

Dan, my point exactly. If a copper lap will cut gemstones one would think it would work on carbide gravers. I got the recharge rollers from Kingsley and use them to charge the laps. One thing I did not do is "score" the plates first. That may be part of the problem. Another is that I annealed the plates to make them softer. I may try again with the 1/2-hard original stock and see how that works.

The disk I used were 1/2 hard,don't think I knew anyone that annealed them.

 

[pmace]

I cut some new copper laps (2" x 4" x 1/16") and left them 1/2 hard (as the stock came from McMaster Carr). I sanded the factory coating off with 120 grit sandpaper. Sprayed each plate with a little isopropyl alcohol and applied a little dab of diamond powder to each (one grit per plate). Spread the powder around with my finger and polished a flat graver with each grit (1200, 3000, 50000). Works great. 1200 cuts well enough to take out a chipped tip in a few strokes, the 3000 cleans it up and the 50000 puts a mirror polish on in a few seconds. The alcohol is enough to move the swarf out of the way, is not as messy as oil and dries faster than water. I tried pre-charging one lap with a roller and I don't think it works as well as the powder in alcohol.
I've got some 350 grit powder and may try one for more aggressive cutting, like on the sides as the graver gets too wide.
The 1200 and 2000 grit diamond stones and the ceramic lap are now resting comfortably in the drawer.