Quantcast
  • We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

Waterstones: Can't poilish the back of a blade

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

Fromey

Established Member
Joined
22 Sep 2010
Messages
570
Reaction score
0
Location
Frome, Somerset, UK
I have a 3000/8000 combination waterstone. After flattening the back of a plane iron and then sharpening it on oil stones (course, medium, fine) I move on to polishing the edge. This works wonderfully and I get a mirror finish quite easily. However, as I chase the wire off the back of the iron, rather than polishing it up, it actually dulls the metal compared to coming off the fine oil stone. I know metal's coming off because a waterstone slurry develops and it goes black. What I'm wondering is that I may be pushing too hard and so producing too much slurry which is not polishing.

Is there a trick to this (such as using copious amounts of water) or is it normal and/or nothing to worry about?

Thanks.
 

Mr T

Established Member
Joined
25 Feb 2008
Messages
1,109
Reaction score
0
Location
Ilkley, West Yorkshire
Hi

Do you get the dulling with the 8000 grit or just the 3000? I find that the 3000 will give a duller surface. For instance going from 600 grit wet and dry when lapping a blade to the 3000 water stone it will go from shiny to dull, don't know why. But the 8000 should give a fairly shiny finish.

I suppose the test is does it get your blade sharp regardless of whether it's shiny or dull!

Chris
 

jimi43

Established Member
Joined
12 Mar 2009
Messages
6,921
Reaction score
0
Location
Kent - the Garden of England
It's quite easy to slightly lift when you are concentrating on "polishing" and end up dulling the edge.

Don't worry too much about polishing anything but the extreme edge. It's the cutting bit after all.

Or just try Scary Sharp.... :wink:

Jim
 

Jacob

Established Member
Joined
7 Jul 2010
Messages
16,119
Reaction score
3
Location
Derbyshire
Fromey":igqozgbb said:
I have a 3000/8000 combination waterstone. After flattening the back of a plane iron and then sharpening it on oil stones (course, medium, fine) I move on to polishing the edge. This works wonderfully and I get a mirror finish quite easily. However, as I chase the wire off the back of the iron, rather than polishing it up, it actually dulls the metal compared to coming off the fine oil stone. I know metal's coming off because a waterstone slurry develops and it goes black. What I'm wondering is that I may be pushing too hard and so producing too much slurry which is not polishing.

Is there a trick to this (such as using copious amounts of water) or is it normal and/or nothing to worry about?

Thanks.
Doesn't matter about actual polishing. Modern sharpening is all a bit exaggerated and semi mystical. Why move from oilstone to waterstone? Where did you encounter this bit of cr@p advice? Ignore it. Just stick to oil - and don't over do it.
 

BigShot

Established Member
Joined
15 May 2009
Messages
460
Reaction score
0
Location
Manchester, UK
"Waterstones: Can't poilish the back of a blade"
Perhaps a bookshop isn't the right tool for the job.

Ba-dum tschhhh.

Sorry - carry on.
 

bugbear

Established Member
Joined
16 Jul 2004
Messages
13,074
Reaction score
0
Location
North Suffolk
Fromey":33a3h4vv said:
I have a 3000/8000 combination waterstone. After flattening the back of a plane iron and then sharpening it on oil stones (course, medium, fine) I move on to polishing the edge. This works wonderfully and I get a mirror finish quite easily. However, as I chase the wire off the back of the iron, rather than polishing it up, it actually dulls the metal compared to coming off the fine oil stone. I know metal's coming off because a waterstone slurry develops and it goes black. What I'm wondering is that I may be pushing too hard and so producing too much slurry which is not polishing.

Is there a trick to this (such as using copious amounts of water) or is it normal and/or nothing to worry about?

Thanks.
Coupla' things; what (particular) oil stones do you have? do you go straight to the 8000 grit, or via the 3000 grit?

I'm thinking of this (of course):

http://sharpeningmadeeasy.com/grits.htm

However, surface shinyness can also be deceptive. Anyone who's done much metal finishing will have encountered the unpleasant phenomona where a surface appears fairly shiny on a coarse grit, but when polished further appears shinier but scratched.

BugBear
 

Fromey

Established Member
Joined
22 Sep 2010
Messages
570
Reaction score
0
Location
Frome, Somerset, UK
Thanks for your comments. I'm using three new Norton oil stones (course, medium, fine; not sure what the grit numbers are for these). I test my edges by pushing/slicing through the edge of a piece of paper. I've noted that although coming off the fine oil stone is indeed sharp, a blade gets much sharper after a polish on the 3000 grit waterstone. Probably not that much improvement after the 8000 grit stone, but since it's on the other side, I give it a go.

I understand that it's only the very cutting edge that needs to be honed the most. Thus, I don't sweat trying to get the entire bevel polished. As for the back, I simply thought I'd polish it up a bit since I was at it, but was struck by the observation that it didn't work. Next time I'm at it, I'll try going directly to the 8000 grit stone.

The reason I'm jumping from oil stone to waterstone is because I can't find an Arkansas stone (that isn't silly money).
 

bugbear

Established Member
Joined
16 Jul 2004
Messages
13,074
Reaction score
0
Location
North Suffolk
Fromey":2jp8lx4k said:
Thanks for your comments. I'm using three new Norton oil stones (course, medium, fine; not sure what the grit numbers are for these).
They're listed on the table I linked to.

BugBear
 

Mr T

Established Member
Joined
25 Feb 2008
Messages
1,109
Reaction score
0
Location
Ilkley, West Yorkshire
Doesn't matter about actual polishing. Modern sharpening is all a bit exaggerated and semi mystical. Why move from oilstone to waterstone? Where did you encounter this bit of cr@p advice? Ignore it. Just stick to oil - and don't over do it.
One reason might be to stop getting oil on your work.

Chris
 

Jacob

Established Member
Joined
7 Jul 2010
Messages
16,119
Reaction score
3
Location
Derbyshire
Mr T":1oo0uw8c said:
Doesn't matter about actual polishing. Modern sharpening is all a bit exaggerated and semi mystical. Why move from oilstone to waterstone? Where did you encounter this bit of cr@p advice? Ignore it. Just stick to oil - and don't over do it.
One reason might be to stop getting oil on your work.

Chris
Er, have you ever thought of wiping it off with an old rag? That's what everybody else does (and have been doing since the year dot). I'm surprised you didn't know.
 

RogerS

Established Member
Joined
20 Feb 2004
Messages
17,391
Reaction score
77
Location
In the eternally wet North
Jacob":2l29l8hg said:
Mr T":2l29l8hg said:
Doesn't matter about actual polishing. Modern sharpening is all a bit exaggerated and semi mystical. Why move from oilstone to waterstone? Where did you encounter this bit of cr@p advice? Ignore it. Just stick to oil - and don't over do it.
One reason might be to stop getting oil on your work.

Chris
Er, have you ever thought of wiping it off with an old rag? That's what everybody else does (and have been doing since the year dot). I'm surprised you didn't know.
YAPP....Yet Another Pointless Post
 

Woody Alan

Established Member
Joined
30 Mar 2005
Messages
1,018
Reaction score
3
Location
Norfolk UK
Perhaps It's possible you have contaminated the waterstone with oil and other particles, I certainly wouldn't mix the two methods.

Alan
 

Latest posts

Top