Final polish on 6000 grit waterstone

[J.A.S]

Dear All,

I've taken the bold step of moving from Scary Sharp to Jap waterstones, and have encountered a problem (apart from the infuriating need to keep flattening the damned things), and would be grateful if the Orientally skilled among you could help.

When lapping the back of a chisel, a la DC, all goes well for the 800 and 1200 grits, but I don't seem to get the final 6000 grit polish as mirror-like as I would want unless I allow the Nagura-created slurry to dry first. To get the back like a mirror the stone feels completely dry. Is this normal?

Thanks.
Jeremy

 

[Anonymous]

Hi Jas

The 6000 grit stone is not meant to be submerged in water like the courser grit stones. Yo uare meant to lightly spray it with water in use and thus use it more-or-less dry.

After the 6000 grit you could use Autosol aluminium polish on a piece of float glass to get the final mirror finish BUT in my opinion DC goes overboard on many issues and there is no need to get a mirror finish for the tool to perform correctly (we are working with wood here!!!). The small scratches left on the back of a flat chisel after a little time on the 6000 grit will have no effect at all on the performance of the chisel - all of mine are dead flat and only one has a mirror finish.


Autosol is sold in a tube at car assessory places

Cheers

Tony

 

[Philly]

Jas,
I have found that if the coarser stones are not flattened before use when you get to 6000 grit you won't get a mirror finish on the whole back. This must be due to the iron not being perfectly flat so it does'nt polish the whole thing. Because the 6000 is so hard it doesn't wear like the others. This might sound like rubbish but if you use Scary sharp to flatten the back and then go straight to the 6000 water stone you will get the result you require.
So, before using your waterstones give them a rub on some wet/dry with loadds of water to flatten them. This should solve your problem.
hope this helps,
Philly

 

[Alf]

BUT in my opinion DC goes overboard on many issues and there is no need to get a mirror finish for the tool to perform correctly (we are working with wood here

True. But sometimes you can use the reflection in the back to advantage, particularly to get a 45deg cut. It's much easier for the eye to judge if the right angle is true than just the 45deg one.

Cheers, Alf

 

[Bean]

Whilst i agree with both Tony and Alf and I think DC is a little OTT about lots of tool tuning you would be better to make a small 45 degree block to act as a guide and not use the mirror finish, or am I being tight fisted in not wanting to buy another stone.


Bean

 

[J.A.S]

Thanks for the comments.

I do flatten the coarser stones frequently (every 50 strokes or fewer), and only lightly spray the 6000.

Given your suggestions, I think I must be using the 6000 correctly, i.e. more-or-less dry.

Thanks.

Jeremy

 

[Philly]

Hi All,
Just to say this-a mirror finish IS important. If it isn't there are scratches on the metal which WILL cause small scratches on the workpiece.
A sharp edge is the intersection of two faces. if there are scratches on one face there will be furrows in the edge. Get the back flattened perfectly-you only have to do it once!
Cheers
Philly

 

[Anonymous]

Philly

I have to disagreee with your comment as in my post I did refer to the scratches left from a 6000 grit stone being OK.

These DO NOT hinder the tool's cutting performance OR leave marks on the wood.

I have also tried polishing the tool to a miror finish using Autosol and it cuts no differently to the finely scratched 6000 grit sharpening.

I have used a 6000 grit as the final stone (without mirror polish) for about 3 years now and know that what I posted is factual.

However, I completely agree with the need to flatten the back all the way to the cutting edge. Just doesn't need to be a mirror finish.

Tony

 

[Philly]

Tony,
When I polish with the 6000 stone it leaves a mirror finish on metal. Could you post some pictures to show us the kind of result you are getting?
Cheers,
Philly

 

[Anonymous]

Hey Philly

Happy to oblige but not too sure if they really do justice to the actual mat(ish) finish. Second picture is intended to show blade flatness :wink:

Holding it on the planter that seems to be taking me 2 weeks to glue up as I never get time in the workshop at present :evil:

Cheers

Tony

 

[Philly]

Tony,
Cheers for the pics-unfortunately they don't help much. The "mirror finish" is important on the last inch or so of the back. Are you trying forthe whole back? I can't tell from the photo's (I know how difficult it is with flash photography ) I apply pressure directly over the end of the chisel when finishing it off, not enough to put the blade out of being flat but so the polishing is focussed on the cutting edge end. A little square of wood double-sided sticky taped to the front of the chisel helps do this (and grip it securely without cutting yourself a'la DC)
If you do this you should be able to get a mirror finish on the chisel. You may think it doesn't have that great an effect, but with plane irons it leaves minute tracks on the wood that do show up when you finish the piece. (DAMHIK)
Hope this is a help,
Philly
P.S. will post some pictures of my tools showing what I mean!

 

[Anonymous]

Must admit the finish on that chisel doesn't look right from 6000 grit! I get a shinier more mirror like finish from just 1500 grit W&D (scary sharp)

IIRC, the final stage of polishing on the finer grit waterstones is to build up a bit of 'muddy' slurry with a nagura, and the slurry shouldn't be dry, but the stickiness it engenders means you have to move the iron or chisel with a fairly short stroke, back and forwards, moving across the stone.

 

[Anonymous]

Cheers Philly. You have no idea how many times I have come out of the garage with blood dripping from a finger after flattening a plane iron for a while :?

ESP, I don't bother spending ages with the 6000 grit stone once the deeper scratches from the 1000 have gone. As I stated earlier, I do not agree with DC on many things and the need for a mirror finish (flat is what matters) is one of them as is the fixation with 1/1000" shavings (wood will have moved at least this much by the time the planing is over) from a plane, it's surface left on workpiece is what matters.

To qualify this I will say that I started off following DCs advice to the letter when fettling panes and sharpening chisels but through experience found that the 30-40 minutes or more of effort to turn the chisel you see here into one with a mirror finish is wasted time and effort - I have about 20 chisels which represents about 10-12 hours extra (boring) effort!!!!

With the planes I also found that anything other than flattening the sole and the blade were also wasted effort.

As I say, this is simply my opinion/practice and and one I concluded through trial and error - I do not intend it as advice to others nor as a negative comment on DCs advice.

Show me a professional woodworker (makes a living from woodwork) who has fettled their panes/chisels a la DC. :wink:

Cheers

Tony

 

[Anonymous]

Tony, the mirror finish isn't the AIM of fettling irons & chisels, a la DC - it's a by-product of a truly flat surface. Any surface that's matt must have striations in it that mean light hitting it doesn't reflect truly. Any surface with striations isn't, by definition, flat. If one surface isn't flat, it's not possible to get a truly sharp edge. One of the purposes of the sharp edge is to make the working of the wood less strenuous, especially on difficult woods. Another purpose is to get as near perfect a finish as possible. The fact that the wood will move, post-planing, is irrelevant - it doesn't affect the finish on the surface. The tiny grooves left from a non-flat iron are likely to show up under a natural finish, like wax, oil or shellac; if you recall Krenov, a well planed surface doesn't require sandind - indeed, sanding a surface that's been planed with a really sharp iron can make the surface comparatively rough.

If you were to take the course of finding pro woodworkers who fettle to DC's level, I'd argue that most chippies don't go any further than a bog standard oil stone, at about 600 (that's hundred) grit, so just going to 6000, regardless of finish, is taking things further than those guys go. I certainly don't spend 30-40 minutes getting the back sorted - 5 or 10 with a new blade using SS (TM), and the occasional touch up when honing seems to achieve good results.

Just my tuppence worth, not wanting to get into an argument about it!

 

[Anonymous]

HI Esp

No argument from me mate.
I see what you are saying and completely agree that the mirror is a by-product of a truly flat surface.

I do not need to go to these lengths to get my chisesl to cut very nicely. I have tried mirror finishes using Autosol etc. for a few years but after stopping this practice find the tools work just as well with the fine scratches shown above - I certainly can neither feel or see any difference on the wood.

These scratches in the chisel back are finer than the wood grain and fibre diameter and one cannot see any marks on the wood that reflect the scratches.

My honing guide leaves a mirror finish on the front micro bevel though

Cheers

Tony

 

[Philly]

Hi Tony,
As promised here are some pics of the polished back of a 1/2 inch chisel. This one was flattened with scary sharp then finished off on the 6000 waterstone.
http://groups.msn.com/ukwoodworking/sha ... snw?Page=1

In your last post you said "My honing guide leaves a mirror finish on the front micro bevel though ". I think the problem your having is applying pressure in the correct area and maintaining it whilst moving the chisel over the stone. Try the little block of wood/sticky back plastic trick and see if that helps.

regards,
Philly

 

[Anonymous]

Very impressive results Philly. Was the final finish achieved purely from the waterstone and nagura?

To be honest I don't try to get a mirror finish any more as I have found no difference in tool performance between the chisel I posted earlier with very fine scratches from a 6000 grit waterstone and the mirror finish I used to get with autosol etc.

I knowDC advocates a mirror and many people swear by it but my experience is that I don't need to go that far.

Cheers

Tony