Thread: Lapidary Services for Hones?

Originally Posted by russell4cook

Hi all,

Does anyone know of any businesses that provide hone lapping services? Specifically, I'm looking to get an Arkansas flattened and polished for use as a razor hone, and I'm nervous about being able to get the sandpaper perfectly flat on the glass to do the lapping myself.

Cheers.

Russell,
I've had to flatten a number of arkies recently and gave up doing it with W/D sandpaper. If you buy some SiC powder (Silicon Carbide) and a 1/4 " glass plate or flat marble tile from Home depot, then you'll have all you need to make it flat, relatively quickly, and then you can use the finer grit W/D sandpaper to smooth it out. I used 200 and 400gr SiC. I may buy some higher grit, however, for a better finish. Probably 800 and 1000 and then go to W/D 1500 and 2k. Seriously, the SiC powder makes short work of a translucent arkie. I couldn't believe how much faster it was.

What eventually makes the arkie smooth enough for razors, however, isn't so much lapping as it is steel. Over time, they get better and better.

That said, google lapidary and a bunch of services come up. I nearly went that route myself before trying the SiC powder. If you live near some colleges or universities, it might also be worth it to visit the geology dept and see if they can flatten a stone for you . They'll have lapidary equipment there and geologists are a notoriously fun and generous bunch of scientists. They might even be interested in your interest in rocks.

mark

edit: forgot to mention that I'm talking about the very hard trans arkies. If you've got a softer one, then it's much easier.

Thanks everyone.

I might be able to get into contact with a geology department, as some of my students who work in an oil company studied geology at university...

I've used the SiC grits for waterstones, and it worked well, and I still have some 150# SiC in my cupboard, so I should have a go really.

But I like the idea of just sending it away and it coming back perfectly lapped and polished

P.S. My stone is a Trans Ark from Dan's Whetstones. It's about 0.25 mm out of flat in the middle, at a guess. Just a miniscule chink of light comes through from under the flat edge of my steel ruler.

Check with your local tombstone company. Maybe they can surface grind your arkie.

Hi all.

Well, today I pullled out the 150 SiC grit, drew up grids on the stone with pencil and got on with it. I did both sides, 3 sets of grids, and they look very flat when checked under a flat edge now. Didn't take longer than an hour in total, I think.

Also, after the last grid was removed I kept on lapping to let the SiC break down into finer pieces, by the end the slurry made a finish on the stone finer than when it arrived in the post (by my inexpert judgement!).

You're probably best served by lapping it yourself anyway if you are really concerned with having it as flat as it can be. Changes in temperature and humidity can and do affect flatness, so if you sent it out for lapping it might not be flat anymore by the time it got back to you.

Hi all,

To give a brief update, in the end I did lapped both sides with 150 grit SiC (I let the grit break down and continued lapping, by the end it was certainly much finer than 150#), and then burnished one side with tool steel. By the end of the burnishing, the stone was able to put an edge on my plane blade that was as least as keen as my 2 micron waterstone. Since the Norton 8000 is 3 microns, I'm happy enough with that.

One more question on this topic, does boiling an Arkansas stone change it's shape? I have noticed one or two small pieces of swarf in the surface, and may consider trying to boil them out.

Originally Posted by russell4cook

Hi all,

To give a brief update, in the end I did lapped both sides with 150 grit SiC (I let the grit break down and continued lapping, by the end it was certainly much finer than 150#), and then burnished one side with tool steel. By the end of the burnishing, the stone was able to put an edge on my plane blade that was as least as keen as my 2 micron waterstone. Since the Norton 8000 is 3 microns, I'm happy enough with that.

One more question on this topic, does boiling an Arkansas stone change it's shape? I have noticed one or two small pieces of swarf in the surface, and may consider trying to boil them out.

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Changing the temp of any stone is detrimental to its health. Many a cold stone has been cracked by running it under hot water. Just get it as flat as you can anyway you can and be satisfied with it. Again, check with your local tombstone business or ceramic tile business and maybe they can make it flat for you.