Thread: Flat matt finish on chisels and blades...what 'am I doing wrong?

You won't get a polish at 3000, just a gray matt (nothing wrong with that though). You need to go to 8000 and 12000 to get those sexy mirrored surfaces.

When I was flattening the sole of my Stanley No4 plane I managed to get a good shine with just 800 grit wet and dry paper. The metal has more shine with 250 grit water stone than it does with 400 grit.
Is there different quality water stones?

If you look along the surface of the blade you'll see that it's still quite polished and reflective, even though it appears dull when you look at it straight on. I can't fully explain how it works, but I have read that it has to do with the size of the surface imperfections in relation to the wavelengths of visible light. Basically, if a surface falls within a certain range of roughness on a microscopic scale, light is scattered rather than reflected coherently.

I used to get the same thing with a King 6000 waterstone.

The finish that you are looking for is referred to as "bright" finish, i.e bright, but not necessarily shiny. Someone else was asking about this a while back, and couldn't understand why it was still grey and matte looking after getting into grits in the thousands somewhere.

I think the answer was that it depends o the type of waterstones. For example Shapton stones give a bright finish all the way through.

I don't use waterstones very much - I'm a diamond paste on cast iron block devotee, and that also gives a matte (but very sharp and smooth) result. At the end I go to Shapton 12000 and the brightness is restored.

I've been using water stones over a couple of years now of hobby use and I'm still waiting for the exact ZEN moment when it all comes together reliably and I understand what edge I'm getting

I've found that I often get higher polish on coarser grit stones when there is a lot of slurry. I assume the slurry breaks down to finer grit as it gets worked but it depends on so many things I haven't sorted. e.g. How long the stones has soaked, what sort of steel it is, how flat the stone is, etc, etc etc.

The best process I have followed is to use each stone in 3 passes. 1st at 45o in one direction then 45 in the orthogonal orientation, then at 90o to give straight across score lines. When you move to the next stone stay at the first 45 orientation until the prior pass score lines disappear, then repeat through the rest of the grits.

I've got a 400-1200-6000-13000 set I got from Stu at toolsfromjapan.com which seems to be adequate grit steps, but I don't actually use the 13000 much and the 400 only when reshaping. Generally I have been just using 1200-6000 when touch up sharpening.

+1 for the 12000 Shapton. I finish on that as well, but I work up to it on DMT DuoSharp

If you use the little nagura stone to generate some slurry it will make the job faster.

I've taken a hint from FenceFurniture and use a 240 (or is it 300) diamond plate to swipe the surface flat and generate ultra quick slurry. I never wash my stones and retain the mess deliberately. (bought from Stu at toolsfromjapan).

I did buy some Shaptons off him too. The high ones... 12000 and use 30k for the knives. They are nice indeed. They reek of quality.

The shininess I find is highly variable. Some blades do it, others don't. Some love the 8000 stone and others don't get sharp until 12k. Others, like the cheap Stanley chisels are very sharp at 6000 (I bag them, but they are excellent chisels). Some love the slurry, others don't and some won't get shiny with slurry, ever.

It's highly variable. I'd recon, CHEAT!!!! Get a really good flat back, go to 6000, then just whack it on the buffing wheel with some compound!

Focus on the front and make it sharp. Forget the shininess, I'd rather sharp.... But fake the shiny

Thanks everyone for the great advice!

Originally Posted by Evanism

I never wash my stones and retain the mess deliberately.

I always wash water stones and diamond plates - removes any residual metal particles that are lurking in the slurry.

Originally Posted by tolyinoz

Hi Everyone,

I'm motivated to use more hand tools and in the process just started with my first set of water stones bought online. I have 250, 400, 800, 1000 and 3000 grit stones. I've started by flattening the backs of my cheap chisels and Stanley plane irons before daring to go onto my new set of Cherry chisels and Lie Nielsen planes. I've looked at a countless number of YouTube videos. I started with 250 grit and progressed through the other grits, but noticed that the steel went from a shinny reflective surface to a dull matt grey which I can't seem to polish out.

What 'am I doing wrong?

Thanks in advance.

My sharpening stones include a 1000 Shapton and 6000 and 13000 Sigmas. These are all I need for blades that are already flat.

Starting, as you are, with un-flat blades, you are advised to begin with W/D sandpaper glued to glass, beginning with 120 grit, then 240 grit and moving to 600 grit before on to your 1000 grit stone. The 3000 is too low to end on. Aim for at least 8000.

A possible reason for the dull, matt finish is that you have not rubbed out the scratches from earlier grits, especially the 250, which can mark deeper. Check that the scratch pattern changes as you move up.

Note that you only need the very back of the blade to be smooth/shiny. The remainder only needs to be flat/coplanar.

Some links: http://www.inthewoodshop.com/Woodwor...%20Blades.html

http://www.inthewoodshop.com/Woodwor...carySharp.html

Regards from Perth

Derek

Hi Derek,

Thanks for the advice. I have 240, 400 and 800 grit stones. Do they not do as good a job at flattening as W/D paper?

I was wrong, I bought the Atoma #140 diamond plate: http://www.toolsfromjapan.com/store/...oducts_id=1197

That is AMAZING. Before, using the reddish 240 it took ages to get a back flat, the Atoma is like 80 grit on timber. New Japanese chisels come up super fast.

Its raining today (pyjama day!), so I might sharpen a few more of my new Jap chisel pile.

Originally Posted by tolyinoz

Hi Derek,

Thanks for the advice. I have 240, 400 and 800 grit stones. Do they not do as good a job at flattening as W/D paper?

The waterstones are good for bevels. The lower grits are "grinding" stones. However these stones do not stay flat long, and this can be a disaster on the back of the blade. W/D sandpaper on glass is flat, flat, flat and predictably so. Use it on the backs of blades, especially in the lower grits, which remove metal fastest and affect flatness most.

Regards from Perth

Derek

Originally Posted by derekcohen

The waterstones are good for bevels. The lower grits are "grinding" stones. However these stones do not stay flat long, and this can be a disaster on the back of the blade. W/D sandpaper on glass is flat, flat, flat and predictably so. Use it on the backs of blades, especially in the lower grits, which remove metal fastest and affect flatness most.

Regards from Perth

Derek

Got it!