Discussion in 'Sharpening Station' started by agp, Jan 9, 2019.
Is 140 grit too rough to use to flatten 1k and 3k stones?
Jon mentioned some time ago that rougher finish (deeper scratches) means faster action but less polish. Hence you decide what you need.
Otherwise I am with the vulnerable species.
The Main reason to get a 140 plate is to be "one and done"
and also able to flatten 300 and 200 stones that need alot of flattening.
If you go for a 140 plate, there are options to soften the grit/finish,
like using a small 1200 or 600 diamond or other nagura, etc.
The Atoma 400 plate should flatten reliably down to about 30 microns range,
like Shapton 500 or Chosera 400.
The Atoma 140 comes a bit aggressive OOTB. Use it first for neglected stones of any grit. Very soon it gets smoother. I use it with all stones, up to 8k. With the finest ones it indeed leaves a rough surface. No problem at all. If you don't like the feeling though you may rub the stone with the next coarser one and you will be fine.
The stones I use the 140 on all have these very visible and distinct scratch marks on them. That's what led me to question if 140 is too rough for 1k and 3k stones. I want the 3k to be flat without being groovy.
I use the 140 also on all my stones up to my 8k's. What I do after flattening is take my mini diamond plate of 600 grit and rub the stone in small circles , like building up a slurry, to smooth out the heavier scratches left by the 140.
Use little pressure and lots of water. The grooves will be only superficial.
I feel that with jnats you hear more about
people getting into performance variations
with 140 or 400 or 1200 etc stone surfaces (slurry),
but not sure if it matters as much on syth stones.
small naguras are modest cost if you go that route.
Using a coarse plate to flatten (even fine) stones is no big deal, just helps you get them flat faster is all.
1. If you want your coarse stones to work fast leave the rough scratch marks in them from your coarse grit plate. The sharp scratch marks (of a coarse grit stone) cut faster than a smooth surface will. Try refreshing the rough surface when the stone slows down.
2. If you want your fine stones to work fast then remove the rough scratch marks that come from the coarse plate. Smoothing the surface (of fine stones) allows for a greater stone surface area to contact the steel. Some fine stones flat out suck until made to be smooth.
In a timely coincidence with Dave’s above, I received my Shapton diamond lapping plate yesterday. Using it on my 4K and 6k made a noticeable difference from my previous lapping with the 140 Atoma.
Would a smooth surface improve harder stones more than softer ones?
Shapton plate is approx. Atoma 400 (micron size) equivalent
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