Theoretical question on chisel life

[kreed]

Difficult one to pitch, but what's the view from the 'older' craftsmen on here as to the life of a chisel used daily in a work rather than hobby environment?

The reason for the question is that as a new collector I'm intrigued by one's use of a tool that they trust/rely on/are married to.
I accept that regular sharpening to maintain the cut will lessen the lifespan, but then that's what it's for.

I've collected quite a few & the use & abuse on some of the older ones gives them character & history. (I've cleaned one up with bloodstains on & now wish I hadn't)

 

[Jacob]

It's a bit open ended but chisels I bought new in 1975 ish are still in use. The most used one (1" bevel) is about half gone but I put that down to misuse (chipped edges) and bad sharpening (over frequent grinding on a bench wheel). Now I know how to sharpen and have more chisels anyway, I'd expect them to last several lifetimes.

 

[Argus]

.

Agree with Jacob.

Looking at Ebay (and disregarding the usual tat), there are occasionally good quality old chisels available with plenty of use left in them that were forged when Victoria was on the throne.

New chisels or old, I think it's ultimately a combination of the quality of the steel, the length of hardened stock up the blade and, of course, your sharpening frequency.

But, I suggest it's best to buy quality if you want it to last and most importantly, be happy with it in use.

.

 

[RogerBoyle]

I had a set that I used on site work that I managed to kill :mrgreen: but they did last over 15 years before they died .
All the chisels I have now have a much easier life and I fully expect them to outlast me now. Put it this way I have no need or intention to buy any more
Really don't see the point of having 10-30 chisels of the same size :twisted: :twisted:

Roger

 

[rdesign]

Roger but 9 chisels of the same size is the norm

 

[Racers]

I have old cast steel chisels with two names stamped on, so they last 2-3 life times.

Pete

 

[David C]

One sometimes sees old sets where the favorite is down to a half or a third, but as Jacob says the method of sharpening and grinding is important.

When grinding I always leave a sliver of the previous honing. i.e. never grind to the edge unless there is a good reason, such as a chip. I find that with cabinet work I almost never get a chip. Site work would be different.

Appropriate angles are needed, and prying might chip Japanese chisels which are much harder than ours.

Best wishes,
David Charlesworth

 

[adzeman]

I bought new in 1975 ish

I bought a set in 1955 still good and yes dont over do the grinding.

 

[bugbear]

When grinding I always leave a sliver of the previous honing.

I never grind, and (as you) always leave a piece of edge bevel when removing primary bevel material (which I do on 120 Grit AlZi).

My final bevels (which form the actual edge in conjunction with the back) never see anything coarser than 60 micron, and routine sharpening more normally starts at 35 micron.

This gives excellent edges, and should also maximise the life of the tools.

BugBear

 

[Jacob]

I've been scratching head over BB's and Dave's comments. Which sliver of previous honing gets left behind, bearing in mind that wear is almost always greatest in the centre? And what about wear on the face?
I hone to bring up a burr across the whole edge. If this isn't easily removed by flattening the face this means that there is wear on the face and it's time to grind (or keep honing for a lot longer).
Then ditto with the grind - I would remove all the honed edged, leaving a bit behind would defeat the object.

NB there is a huge range of forms of woodworking activity between "cabinet" and "site" work.

PS Got it! They are talking of sharpening edges which haven't been used!

 

[Cheshirechappie]

Both David C's and bugbear's comments seemed perfectly clear to me.

If it's edge is dulled, hone it (by whatever method you happen to prefer). If it's edge is chipped, or if the flat face is not flat, repair as appropriate - probably by grinding away the damage.

Why would you need to sharpen an edge that hadn't been used?

 

[Paul Chapman]

I've been scratching head over BB's and Dave's comments. Which sliver of previous honing gets left behind

Are you deliberately pretending to be a bit thick again, Jacob :? David's comments were quite clear and sensible.

Cheers :wink:

Paul

 

[Jacob]

No I think you are being a bit thick Paul and you don't understand what I'm saying. But don't worry about it!

 

[bugbear]

I've been scratching head over BB's and Dave's comments. Which sliver of previous honing gets left behind, bearing in mind that wear is almost always greatest in the centre? And what about wear on the face?

On the off chance that your question is honest, and not just noisy rhetoric, I was referring (explicitly, read carefully) to working on the primary bevel.

it is a sliver of secondary bevel that is left, and the secondary bevel is the honed (and polished ) one.

BugBear

 

[Jacob]

If it an edge need sharpening it is because the honed edge (your "secondary" bevel) is worn. More often than not, near the middle. This is the bit which needs honing or grinding down, to remove it, which means you can't really leave "a sliver of bevel" anywhere else. Honing or grinding removes the whole of the previously honed edge, as far as necessary to give you a new edge, or you will be leaving behind a blunt bit.
In fact I think this is a common mistake - people give up honing too soon and leave the most worn bit still untouched. This improves performance over most of the blade but not all of it.
Hence my rule of thumb - honing or grinding; don't stop until you have a burr across the whole edge especially the middle.

 

[Racers]

I only grind the primary bevel if the secondary gets too wide, you don't have to remove all the secondary bevel, and this will be done when honing.

Simple?

Pete

 

[Jacob]

I only (machine) grind (a flat 25º bevel) when the honed edge (bevel and/or face) is so worn or chipped that hand sharpening is too slow. The grinding would go just far enough to remove all the wear.
I often hand grind the rounded bevel on a medium grit, to get there quicker, which means if you don't get a chip you never need to machine grind.

 

[RossJarvis]

I'm getting a little bit confused myself now, but what I thought was being said, is that when the secondary bevel, the sharp bit, has been honed a lot and is getting very wide(deep?), the primary bevel will be ground out to "start again". However there's no need to rough grind all of the secondary bevel off, as the cutting edge will hopefully still be pretty sharp. Once the primary bevel has been ground again, a quick hone of the edge, if needed will leave the chisel sharp. If the whole front of the chisel were rough ground, there would be more work to sharpen and hone the cutting edge.

Is that right, or have I got it wrong?

 

[bugbear]

I'm getting a little bit confused myself now, but what I thought was being said, is that when the secondary bevel, the sharp bit, has been honed a lot and is getting very wide(deep?), the primary bevel will be ground out to "start again". However there's no need to rough grind all of the secondary bevel off, as the cutting edge will hopefully still be pretty sharp. Once the primary bevel has been ground again, a quick hone of the edge, if needed will leave the chisel sharp. If the whole front of the chisel were rough ground, there would be more work to sharpen and hone the cutting edge.

Is that right, or have I got it wrong?

You've understood perfectly.

BugBear

 

[Paul Chapman]

I'm getting a little bit confused myself now, but what I thought was being said, is that when the secondary bevel, the sharp bit, has been honed a lot and is getting very wide(deep?), the primary bevel will be ground out to "start again".

You've got it It's about saving time and not having to hone too much metal that doesn't form the edge. But it's helpful to leave a sliver of the old secondary bevel in place - particularly if you use a high speed grinder. If you grind right to the edge with a high speed grinder, it can easily burn the edge of the blade.

Or get the apprentice to do it and blame him if he cocks it up

Cheers :wink:

Paul