Chisel question

[dst]

Hi guys,

I'm buying some of the basic tools for learning woodworking. I have a stupid question... Specifically conserning dove-tail joints and chisels. Are the size of the chisels critical? I mean for a mortise I assume you want a mortise chisel of the same width as the mortise. But for other work is it as crucial as long as the chisel is smaller than the area you want to remove?

Why I ask, inch or metric: I want to order a few quality chisels but the ones I want are imperial sized and being European I think and work in mm. So say a 3/8" chisel would be a little bit smaller than the 10mm grove I might want to create.

I'm not sure if this even would make sense, but if it does I'd appreciative the input.

Thanks!

[Dozer's Workshop]

I'm probably too newbie to answer, but I think you are ok as long as your chisels are smaller than what you are working on. Every time I have tried to use a chisel that was "Exactly sized" for the hole, something always went wrong...tilted the chisel, needed a smaller hole...I would think its better to sneak up on the final cut size...

I would also think you want them sized not too much smaller than your hole...just think, cutting out a 20mm hole with a 5mm chisel would tke a lot of extra work... (my sad attempt at metric conversion)... maybe aim for a 15mm chisel for that cut just to leave a little wiggle room but not too much.

Oh well, i said my bit...now everyone else can correct me :-)

[mwatkins]

When we're talking dovetails sizing really doesn't matter much. The bigger piece to the puzzel is making sure that the shoulders are either thin enough or angled such that you can get the chisel into the corners of the tails and not damage the edges. If the shoulder on your chisel is too thick you run the risk of bruising the wood as you clean out the edges etc.

[Morton]

I'm the opposite - I work in imperial, but I have used metric chisels for quite awhile. While it's never been a problem in the work (95% of the time - though I just did some mortises that exactly matched chisels sizes and that was NICE) -- honestly, it's been a mental overhead that I haven't enjoyed.

For dovetails and many tasks, it's no problem - I grab either an oversized or undersized chisel (depending on the operation) - but something about (now) having imperial chisels is very nice.

Just an opinion.

[jsiard]

The critical issue when dealing with dove tails isn’t the width of the chisel as much as the bevel on the chisel (in cross section). You want a bevel edge chisel with a lower edge profile that will allow you to get into the corners, a good example are the Lie Nielsen chisels. Something like a firmer chisel won’t allow you to do that. As far as Imperial or Metric I don’t think that really matters a great deal, all my chisels are metric and even though I don’t work in mm I’m close enough. There are a couple manufacturers that are making chisels in imperial measures such as LN and Stanley.

[dst]

Thanks for the feedback guys. I'll just get some cheap ones mm or inch and try it out then I can upgrade if I see the need in the future.

[Steven Reckner]

Even cheap chisels are ok as long as you learn to put an amazing sharp edge on them even expensive chisels are useless after they have dulled for the first time if you don't know how to put a fine edge back on them

[Morton]

Good idea getting some "cheap" chisels and trying it out. I find you can never have too many types of chisels kicking around too - various bevel angles, the most handy to pick up, etc - nice to have a couple of sets over time.

[Bob Rozaieski]

The critical issue when dealing with dove tails isn’t the width of the chisel as much as the bevel on the chisel (in cross section). You want a bevel edge chisel with a lower edge profile that will allow you to get into the corners, a good example are the Lie Nielsen chisels. Something like a firmer chisel won’t allow you to do that.

Not true at all. I've chopped hundreds of dovetails with straight sided firmer chisels (as did our ancestors before bevel edged chisels were the norm). As long as the chisel is narrower than the base of the pin (typically the tighter part of the joint) then it's not an issue. Just angle the chisel slightly to clean further into the corner. The saw gets right into the corner, so the chisel doesn't have to go that far really, but it can if you just angle it a little.

To the OPs question, it is very nice to have chisels sized to match the system you work in (metric or imperial) and also to match your other tools (chisels match mortise chisels which match plow plane irons, etc.). This way they can be used as gauges too and not just for chopping. I do a lot more with my chisels that just cut wood. I "measure" with them, set up gauges, step off joinery, etc. It's not necessary for the chisels to be sized the same as everything else, but it's a nice to have.

[Darnell Hagen]

Bases of pins are easy, as there is lots of room to angle the chisel. It's the bases of the tails, paticularly with skinny pin London style dt's, that the side land height becomes an issue.

[Bob Rozaieski]

Bases of tails are still not an issue as long as the chisel is narrow enough. If one uses a 3/4" board and cuts London pattern dovetails with a 1:8 slope (which results in an included angle at the thinnest point of the pin of about 14 degrees), the width of the base between tails will be about 3/8" wide if the thinnest point of the pin is zero. This is plenty of room to angle a 1/8" chisel. If the board thickness is reduced to 1/2" with the same 1:8 slope, the width of the base between tails becomes about 1/4" which is still plenty of room to angle a 1/8" chisel between the tails. I've done it plenty of times and it works fine. I have a 1/16" chisel even, but rarely need to use it.