Flattening/Dressing/Chamfering Belgians and Slates

[1315]

Thought I'd ask for tips before I mess something up. I have a Belgian Blue + Coticule to tune up, but wondering about slates too.
I have an Atoma 400, some 240 SiC (+ floor tile), and a BB/Coti bout to start with.
Anything I need to know?

 

[deltaplex]

I'd use the loose SiC + tile for any flattening/macro chamfering work, unless you're trying to save any of the powder.

 

[Benuser]

I use an Atoma 140 for deglazing once a year or so my BB, or to occasionally raise mud on BB or Coticule. One of the advantages of the Atoma: the mud is safe. No risk of diamond particles in it, with all the horrible effects it would have. By the way: Coticule mud starts quite coarse. Have reprofiled a abrasion resistant soft stainless with it — a SAK. The Coticule cover a huge range: 800 up to above 8k is very common. Belgian Blue, muddy or diluted, are close to 4k. Must have to do with the working of the slate vs. the Coticule's clay.

 

[Seemore]

I just emailed Ardennes-Coticule, where I got my BBW, a couple days ago with the same question. Here’s what Rob said (mine is a BBW only, not coticule):

“I use a very fine sandpaper #400.
I put this on a table and flatten the stone without water.”

 

[1315]

For Arkansas: How to Flatten a Stone (Lapping an Ark)

 

[Heckel7302]

I use atoma 140 on mine when it needs it, otherwise atoma 1200 for conditioning and to raise a slurry. I think you'd be fine just using your 400.

 

[Neutri]

Maybe I should create another thread, but I was wondering what's the difference between flattening, dressing and chamfering?

 

[Heckel7302]

Maybe I should create another thread, but I was wondering what's the difference between flattening, dressing and chamfering?

Flattening=making the stone flat if it isn't
Dressing/conditioning=changing the surface of the stone to rougher or smoother and/or removing embedded swarf
Chamfering=easing the edges of the stone so they aren't sharp, basically rounding over the edges so they aren't 90 degrees

 

[Neutri]

Flattening=making the stone flat if it isn't
Dressing/conditioning=changing the surface of the stone to rougher or smoother and/or removing embedded swarf
Chamfering=easing the edges of the stone so they aren't sharp, basically rounding over the edges so they aren't 90 degrees

Thanks! So if I take the Arkansas thread, I could technically just stop after flattening? Or does a stone need to be dressed to be used?

Why the need to round the edges over? Comfort?

 

[stringer]

Thanks! So if I take the Arkansas thread, I could technically just stop after flattening? Or does a stone need to be dressed to be used?

Why the need to round the edges over? Comfort?

You could stop after flattening. Depends on what you are going for. A translucent Arkansas can be flattened with very coarse SiC. Leave it with a coarse surface and you will have a fast medium stone. Condition the surface with a progression finer sandpaper or diamonds and you will create a much slower finer cutting surface that could put the final edge on a straight razors. Sharp corners can damage the edge. Especially if they are proud of the middle. Best to knock them down and chamfer them a little so that the blade is making contact with the stone across the whole surface and not riding the edges.

 

[Neutri]

You could stop after flattening. Depends on what you are going for. A translucent Arkansas can be flattened with very coarse SiC. Leave it with a coarse surface and you will have a fast medium stone. Condition the surface with a progression finer sandpaper or diamonds and you will create a much slower finer cutting surface that could put the final edge on a straight razors. Sharp corners can damage the edge. Especially if they are proud of the middle. Best to knock them down and chamfer them a little so that the blade is making contact with the stone across the whole surface and not riding the edges.

Thanks a lot

 

[HumbleHomeCook]

Flattening can also lead to sharp edges so that's another good reason to chamfer them.

 

[Legion74]

Coticules and BBW are not so hard, and unless they are really out of flat you will just be able to do it all with an atoma 400 under running water. Lap it, chamfer the sharp corners a little, and use the stone. No further dressing is needed, especially if you are using it for knives. One or two strokes and any atoma scratched will be erased.

 

[1315]

Thanks guys. Appreciate the help.