Sharpening chisels

[imamartian]

.. and before you tell me, i know it's been asked before... but what i don't get is that the advice tends to be... sharpen at between 25 and 30 degrees !!!! use this machine or this stone or you'll eventually learn "the secret".

Well i have sharpened chisels before, cut through a single piece of paper, hanging in the air, then rubbed the chisel on the diamond stone for 2 or 3 more seconds and managed to make it virtuallt blunt.
Ok, so a bit of exagerating going on there, but my point is..the angle is crucial... not only degrees, buit seconds too surely?
I have a honing guide, but as hard as you tighten it up, it's bound to slip a millimetre..

And even sharpening a knife blade.... how is it done?

 

[^woody^]

www.stanley-prozone.com/pros.html

Some of the videos are a bit suspect in terms of how the guy does things, but the chisel sharpening ones are OK

 

[big-all]

the angle is a compromise 25 and 30 is pretty normal
shallower the angle the sharper the chisel but the weaker the cutting edge

steeper the angle longer it remains fully sharp all be it with reduced sharpness

the crutial crutial points of sharpening a chisel is smooth the back "FLAT"
must be flat no angle no pitting in the back because pitting will directly affect the cutting edge also grind cold if it turns blue or discolours it has softend the metal and make shure you remove the burr

the honing angle is to make the final sharpening easier and allow you to hone several times before regrinding

a sharp chisel is much safer than a blunt one in normal use

 

[imamartian]

Thanks Woody.

But oh......... my........... god........... the........... guy........... talks........... so........... slowly...

 

[imamartian]

the angle is a compromise 25 and 30 is pretty normal
shallower the angle the sharper the chisel but the weaker the cutting edge

steeper the angle longer it remains fully sharp all be it with reduced sharpness

the crutial crutial points of sharpening a chisel is smooth the back "FLAT"
must be flat no angle no pitting in the back because pitting will directly affect the cutting edge also grind cold if it turns blue or discolours it has softend the metal and make shure you remove the burr

the honing angle is to make the final sharpening easier and allow you to hone several times before regrinding

a sharp chisel is much safer than a blunt one in normal use

so how often do the pros sharpen their chisels? or do they just buy new? and how do you sharpen a utility knife blade?

 

[big-all]

you sharpen chisels when they need it

if you are using a chisel a lot it could be 4 or 5 hones in a day all depends on the work
if the chisel bends splits the work its way way blunt

cheap chisels are softer metal so easier to sharpen/hone but blunt very quickly

i like a lot of people have the yellow and red marples at £50 for 6 set

they last for years

i do some anal things but re sharpening stanley blades is not one and i have a sheppah tiger sharpening system

 

[noseall]

big-all is spot on.

also keep the flat side polished and keen. and keep it flat against the oil stone at all time. do not tilt the flat side.