Atoma 400 or 1200?

[kohalajohn]

Yeah, everyone will say get both.

But for lapping, not for raising slurry. So I'm thinking 400 over 1200.

I use 400 grit sandpaper for lapping now. So I'm leaning toward a 400 in atoma diamond 8x3 for lapping.

Thoughts appreciated.

 

[Alum of Potash]

How about a coarse/extra-fine DMT Duo-Sharp? That way you can have both.

 

[David]

400, no question about it. A 1200 will not hold up to lapping.

 

[kohalajohn]

400, no question about it. A 1200 will not hold up to lapping.

yeah, that's what I thought.

 

[eKretz]

Yep.

 

[RayClem]

For serious lapping, 400 grit removes material a lot quicker. However, since this is not the final smoothing of the surface, you can use something other than diamond. I tend to use Silcon Carbide wet/dry paper backed by granite to start (220, 400 or 600 depending up the amount of material you need to remove). Then when I get the stone flat, I use an Atoma 1200 to refine the surface. SiC paper is a lot less expensive than a diamond hone.

 

[psfred]

Loose silicon carbide grit and a cast iron plate is even better for serious stone flattening as the rolling grit cuts much faster. A 400 grit Atoma will work just fine, but it will be slow if you need to remove the dish in an old Arkansas or similar stone and excessive pressure will strip the diamond off.

SiC W/D paper on something nice and flat works well, I've done that quite a few times and have not spent anywhere near what the Atoma costs. However, for just maintenance, the Atoma is probably a better value and will give you flatter stoned -- paper tends to very slightly convex them due to greater wear in the center of the paper, even with good technique.

1200 is way too fine for flattening anything harder than run of the mill synthetic stones, it will take forever and sticktion will drive you crazy. That said, for fine stones, a 1200 grit finish may work much better for honing -- on something like a Kitayama, for instance.

 

[Namkcakram]

Loose silicon carbide grit and a cast iron plate is even better for serious stone flattening as the rolling grit cuts much faster. A 400 grit Atoma will work just fine, but it will be slow if you need to remove the dish in an old Arkansas or similar stone and excessive pressure will strip the diamond off.

SiC W/D paper on something nice and flat works well, I've done that quite a few times and have not spent anywhere near what the Atoma costs. However, for just maintenance, the Atoma is probably a better value and will give you flatter stoned -- paper tends to very slightly convex them due to greater wear in the center of the paper, even with good technique.

1200 is way too fine for flattening anything harder than run of the mill synthetic stones, it will take forever and sticktion will drive you crazy. That said, for fine stones, a 1200 grit finish may work much better for honing -- on something like a Kitayama, for instance.

Ha! I thought I was the only weirdo on here who likes the friable imanishi Stones!

I’ll just say same as everyone else, 400 for lapping. The lapped surface quality you leave on top of your stone only really seriously impacts the finishing capabilities on Arkansas stones IME. Everything else seems to burnish and completely level out within minutes after flattening, so the 400 finish is no concern.

Also I wouldn’t use any diamond plate on a hard Arkansas, you’ll flatten your diamond plate in no time!

 

[Jnatcat]

Get both, we’ll get the 400 or 1200 plate then get the other as a replacement stick on and stick it on the back side and you can have one for lapping and one for slurry

 

[RayClem]

Ha! I thought I was the only weirdo on here who likes the friable imanishi Stones!

I’ll just say same as everyone else, 400 for lapping. The lapped surface quality you leave on top of your stone only really seriously impacts the finishing capabilities on Arkansas stones IME. Everything else seems to burnish and completely level out within minutes after flattening, so the 400 finish is no concern.

Also I wouldn’t use any diamond plate on a hard Arkansas, you’ll flatten your diamond plate in no time!

Another stone that needs a "polished" surface is the Zulu Grey from South Africa. The guy who quarries these very hard stones laps them flat and then polishes them to 1200 grit level. Some people finish on these stones dry. but they can be used with water or with slurry.

 

[kohalajohn]

I now have my 400 atoma and have a 1200 atoma glued to the back. A super handy combo stone.