Fishtail chisels?

[Derek Cohen]

If you start with this tail board ...



.. you will require this pin board ...



... to achieve this ...



Observation #1: clearing the waste at the corners of the pin socket - which are a result of the slim tails - is a delicate task. There is no room for error.

Observation #2: Wilber, the base of your tail is 1/4" wide. Mine is 1/8" wide. I do not consider yours "slim". 

Regards from Perth

Derek

[AHill]

Cherubini is correct.  You don't NEED fishtail chisels.  I doubt they were common in tool boxes prior to around 1850.  BUT, they do come in handy when you encounter situations such as Derek describes.  More commonly, I think you'll find them more in use for carving than traditional cabinetmaking.  I own a set from Blue Spruce.  They are phenomenal chisels.

BTW, Cherubini also thinks a block plane is not necessary. He prefers a wooden smoother to accomplish the same tasks.

[frigator]

According to this site the fishtail or butterfly chisel was the original shape of the chisels made centuries ago in Japan. I think this is the chisel I have. It may be white steel instead of blue.

http://www.japanwoodworker.com/Product/1...umura.aspx

[jgourlay]

I really like chisels as a tool and when I started this whole thing I acted like I had more money than sense.  Thus, I have way too many chisels.  A few years ago I went to do my first half blind dovetail drawer and bought a 5/8" "bachi nomi" from Japanwoodworker.  Having used it for a while, I now completely do not understand why the 'normal' chisel pattern is the normal chisel pattern.

*IF* I was going to do it again, I would have a set of bachi nomi, one set of mortise chisels, and 2 yellow plastic handled paint-can-opener grade chisels and call it done.  The Bachi Nomi's are far more versatile, they have better balance, blah blah...

[Wilbur Pan]

If you start with this tail board ...



.. you will require this pin board ...



... to achieve this ...



Observation #1: clearing the waste at the corners of the pin socket - which are a result of the slim tails - is a delicate task. There is no room for error.

Observation #2: Wilber, the base of your tail is 1/4" wide. Mine is 1/8" wide. I do not consider yours "slim". 

Regards from Perth

Derek

Hi Derek,

Just to be clear, I think this is the usual terminology when describing the parts of a dovetail joint:



Which is why I thought “slim pins” (or “slim pin socket”) was a better term than “slim tails”.

Also, that particular board that I posted has pins sockets that are 1/8” at the base. That’s a 1/16” chisel in the photo. You can confirm that with the ruler markings, which are 1/16”.

I agree that clearing the waste out from between the tails when you make a pin socket that thin is a precision task. There are a number of ways to accomplish that. A skew chisel that’s narrow enough to get in there is one. A regular chisel that’s narrow enough so that you can angle within the gap it is another. Here’s a third:






As far as using a fishtail chisel for the back corners of the tail socket in a half-blind dovetail, I don’t think that is a precision operation at all. If there’s a little mismatch in the fit in the area of that back corner, that’s not going to materially affect the fit or strength of the joint one bit. So I’ll use a regular chisel for that as well. 

Take care,
Wilbur

[rwe2156]

If you want to clean up 1/2 bllinds, the fishtail is handy, but not indispensible.  I have one but have to remind myself to use it.

For this purpose, bear in mind you need a single bevel (flat on one side) fishtail.  LN is the only one I know of.

Most other flat fishtails are carving tools and are double bevelled, but can be ground flat on one side if you don't want to pay the LN price (this is what I did to an Ashley Iles).

[Derek Cohen]

Hi Wilbur

I agree - your terminology is more correct than mine. 

But .. I'd like to see the pin board that goes with those tails ... I've seen those tails before. It is the pins that are the issue here, that is, how to pare them without a fishtail chisel. 

I've made many drawers with dovetails like these. They require care when paring, and I think that there is a lot of macho nonsense on forums about using any old chisel to clean out socket corners. I have no doubt that it can be done ... but why would one fight so to do it the hard way, when the right tool is a fishtail chisel. 



Regards from Perth

Derek

[Mike Brady]

The size or width of the pins has no bearing on the utility of the fish tail chisels....we are talking about paring the corners of tail sockets.  Skinny pins are a matter of preference.  Using them makes for an inherently weaker joint and relies on greater proportion of side grain to end grain gluing area.  Yes, you do have to treat those narrow pins very tenderly because they are all that stands in the face of a joint failure disaster.

Those of you wishing to dispose of your fishtail chisels please PM me.
  I prefer Lie-Nielsen, but will accept lesser brands.

[Bibliophile 13]

FWIW, Moxon includes a fishtail chisel alongside a skew as standard equipment for the joiner.


If, however, the Moxon chisel is drawn to scale, it looks as though it's the widest chisel in the set.  I almost wonder if it's a way of getting a wide chisel but conserving material.  Back in the day, a blacksmith's labor was much cheaper than his material, and metal work was normally sold by weight, so it would make sense that the widest chisels, especially those designed primarily for pairing, would be made in "fishtail" patterns.

Back to the modern world: I don't have a fishtail chisel myself, but the last time I did half-blind dovetails, I really wished I had one.  I got tired of switching back and forth between my two skew chisels.  One option would be to just grind the sides of a regular 1/2" chisel down to a fishtail profile., but I haven't the patience for that.

[hbmcc]

Not to short shrift one of the prettiest pieces of furniture I was given the pleasure to watch being built.... I think those "skinny" pins are as useful as shish kabob sticks for roasting weenies over an open fire. Kabobs break simply under weight of the highly processed load they bear. I am pretty sure the half-pins save the day when used with "skinny" full pins.

No, convenience is a poor reason for insisting on a weak joint to justify a butterfly chisel in order to cut it. Just in case, I have nails to reinforce such butt joints when the rest of us--with softer, and weaker, wood than Derek--attempt such beauty. 

PS. That's a beautiful piece of furniture, including the exposed drawer joints.