A chip off the old chisel

[mickthetree]

well a chip off the new chisel actually.

I was just using one of my ashley iles chisels to chisel to a line in some oak and a lump just came flying off.

Fair doos I was giving it a whack with a mallet, but its taken a ruddy big chip out of the end.

The primary bevel on the chisel is as it came. I have only polished that, but I put a slightly higher bevel on the end 1mm or there abouts, as I thought thats what was required if using them for chopping?

What have I done wrong? Am I misusing the chisel?

I'd like to know so I dont do it again. going to need a hefty re-grind.

 

[Benchwayze]

Are you cutting a mortice in oak? With a bevel-edge?

It's possible of course. I did it for years, until I collected proper mortice chisels. But I always took shallow cuts.

Even so, I don't think that much metal should break away from a mallet blow. I'd want to show Ashley Isles to be honest.

regards
John

 

[mickthetree]

no no, its a lap joint, I was just chopping back to the base line. I was taking no more than 1mm of material off at a time so I wasn't belting it.

Should have cut closer to the line and paired it back I suppose.

There are no foreign objects in the wood as far as I can see.

They are great chisels, I'm not doubting that, but I assume I must be doing something wrong???

Come to think on it, this is the chisel I have used least of the 4 I bought. The others are all fine and have had a tap with a mallet.

 

[Benchwayze]

Sometimes you can come across a surprisingly hard pocket in many timbers, and this can cause problems.

All my bevel-edge chisels have 30 degree secondary bevels on them which are usually about 1/8" (2.5mm app). The only chisels used with a single bevel, as far as I was taught, are Japanese chisels. And even those have secondary bevels put on them by some workers.

I have had similar accidents myself, but usually because I was trying to pare off too much material, and too deep, or I tried to pry too much away.

If the chisel is sharp, and you aren't bashing the Almighty out of it, then that shouldn't happen in good timber. I'd have a look with a lens, to see if there are any hairline cracks further back too. If there are you'll have to grind them all away.

I would still be tempted to talk to Ashley Isles though.

HTH
John

 

[mickthetree]

I'll do that, cheers John!

 

[Benchwayze]

All the best . I hear Ashley Isles are quite receptive. So you might well get a favourable reaction.

John

 

[Crooked Tree]

Hi Mick,

I have only cut two trial mortices in oak, but had no problems with the bevel edge chisel that I was using. This was only a plastic handled bevel edged Marples, with (I think) a 25 deg primary from the factory and a ~ 30 deg secondary applied by me. This was before I got my waterstone too, so it may not have been super sharp. I was taking it carefully, though and taking out small amounts at a time because these were the first mortices that I had ever cut.

 

[woodbloke]

A chip like that ought not to have happened in a quality chisel like this. When I did the big chisel test for F&C last year the AI's held up well to sustained heavy chopping into something far tougher than oak. The other issue to think about is that the first couple of mm of the blade may be softer so you might need to grind past the mushier stuff in order to get to the good steel.
I'd contact the supplier in any case...if it's Matthew at WH there won't be any problem with a replacement - Rob

 

[Philly]

Ouch! Mick, that shouldn't have happened - definitely speak to AI!
Philly

 

[bugbear]

A chip like that ought not to have happened in a quality chisel like this. When I did the big chisel test for F&C last year the AI's held up well to sustained heavy chopping into something far tougher than oak. The other issue to think about is that the first couple of mm of the blade may be softer so you might need to grind past the mushier stuff in order to get to the good steel.
I'd contact the supplier in any case...if it's Matthew at WH there won't be any problem with a replacement - Rob

In the case shown, I think the end may be harder (more brittle).

If it were softer the edge might have folded, or bent, but not snapped.

IMHO, using a mallet on a (pretty much) 25 degree single bevel edge, on bevel edged chisels, in oak is moderately stiff usage. If the force on the chisel is perfectly aligned, I wouldn't expect any damage, but if there's any levering moment, it's starting to get dicy.

BugBear

 

[woodbloke]

In the case shown, I think the end may be harder (more brittle).

If it were softer the edge might have folded, or bent, but not snapped.

IMHO, using a mallet on a (pretty much) 25 degree single bevel edge, on bevel edged chisels, in oak is moderately stiff usage. If the force on the chisel is perfectly aligned, I wouldn't expect any damage, but if there's any levering moment, it's starting to get dicy.

BugBear

Good point BB, a softer edge would have indeed bent, not snapped - Rob

 

[mickthetree]

Hey all

I've spoken with Matthew at Workshop heaven. As always, very helpful.

I'm sure this is down to user error. As said, I have left the original bevel (approx 23 degrees) and just honed the end 1mm or less a couple of degrees higher, which isn't sufficient for chopping. It really needs a 30 - 35 degree secondary bevel at the end for chopping.

I'm going to regrind this and leave it set up for paring as it does such a good job of it.

I could send it back to AI but to be honest I can do it myself and save the postage.

He made a good point, that if you have a full set for chisels, you can set the 1/4", 1/2" and 3/4" ones for chopping and leave the ones in between for paring.

ho hum, I guess I'll just have to get the full set then :roll: :lol:

 

[bugbear]

In the case shown, I think the end may be harder (more brittle).

If it were softer the edge might have folded, or bent, but not snapped.

IMHO, using a mallet on a (pretty much) 25 degree single bevel edge, on bevel edged chisels, in oak is moderately stiff usage. If the force on the chisel is perfectly aligned, I wouldn't expect any damage, but if there's any levering moment, it's starting to get dicy.

BugBear

Good point BB, a softer edge would have indeed bent, not snapped - Rob

IIRC Odate speak of "taming" a new Japanese chisel, which is prone to being too hard at the tip - it's very difficult to heat treat non uniform objects.

The "taming" is simply grinding away more metal when sharpening, so that you get past the too-hard tip quicker.

BugBear

 

[Benchwayze]

There is what looks to be a nice paring chisel on the 'fleabay' at the moment.

Item No. 360224769571

 

[woodbloke]

Hey all

I've spoken with Matthew at Workshop heaven. As always, very helpful.

I'm sure this is down to user error. As said, I have left the original bevel (approx 23 degrees) and just honed the end 1mm or less a couple of degrees higher, which isn't sufficient for chopping. It really needs a 30 - 35 degree secondary bevel at the end for chopping.

I didn't really read the OP , but Matthew's right, a slight increase in the bevel to say 27deg, isn't really enough for chopping into oak. 30deg would be the min bevel for this sort of work...35deg would be too much - Rob

 

[Jake]

I am probably missing the point, but how is a higher secondary bevel going to help avoid a massive chip off the blade like that which goes back way past a secondary bevel and into the meat of the primary bevel?

(as opposed to edge crumbling etc)

edit, oh OK, another reminder to read the thread - and refresh one's memory of the photo before posting, it isn't as big as it was in my mind!