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View Full Version : Fishtail vs. skew chisels?



ian maybury
05-11-2015, 7:08 PM
Pardon my lack of knowledge, but i've been digging about on this in preparation for an upcoming project - it can take over a week to get delivery and be expensive if anything needs to be bought as it's usually a case of using a UK or German supplier.

I've a couple of very nice Japanese fishtail chisels which have so far had a little use and done fine, but my joint cutting experience is very limited. I'm as a result trying to figure out in advance if there's anything that skews do over and above.

The web or indeed searching here doesn't bring up much more than 'i've got this', or 'i did that' - but very little on specific technique or tool set up. They seem to get used interchangeably - for e.g. stuff like clearing out sockets (?) in a half blind dovetail. Guess i'm wondering about the nitty gritty of the tools in use, and how this may determine best choices.

A skew for example isn't going to be much use if the angle of the skew isn't at least as great as that on the pin, but in practice they seem usually to be sharpened to a much greater angle. The sides of a fishtail presumably also need to be angled more than the pin.

A skew if made from a narrow chisel can perhaps at times be narrower than a fishtail, but that may or may not be a big advantage?

I seem to be drawn more to the fishtail in that it permits most of the time keeping the shank of the tool square to the work.

Fishtails are a bit awkward to sharpen, but filing a short/narrow flat in the right place on the shank seems so far to have made them very do-able in the Veritas Mk 2 guide.

Is there possibly a great world of skew/fishtail chiselling applications out there with considerations attached beyond the fairly narrow scenario outlined?

Paul Sidener
05-11-2015, 8:02 PM
If you are just looking at dovetails, the fishtail is better in my opinion. You can clean both sides of a dovetail with a fishtail. If you use a skew you will need both a right and a left. I find I can do pretty much the same job with a small bevel edge chisel. I have a fishtail that I don't use it much. Mainly because it is more difficult to sharpen.

Tom Bussey
05-11-2015, 8:05 PM
I have skew chisels but I would think fishtail chisels would be much better for all around use. I would love to own a fishtail or two.

Brian Holcombe
05-11-2015, 8:14 PM
I'm awaiting a fishtail because I find skew chisels to be a bit tedious.

ken hatch
05-11-2015, 8:43 PM
Why not roll your own. They ain't pretty but....they work when needed.

I have a couple of homemade and a Koyamaichi fish tail. None of 'em get used much but sure are nice to have when needed.

BTW, I find them no more difficult to sharpen than any other chisel and I expect easier than a 'slew".

http://i257.photobucket.com/albums/hh222/VTXAZ/chiselFishtail20150511_zpstf5xbnor.jpg

ken

Jim Koepke
05-12-2015, 2:12 AM
A fishtail would have an advantage in half blind dovetails.

For through dovetails and other applications a skew chisel would have some advantage.

The skew pushed straight creates a lower cutting angle and more of a slicing cut.

My two skews were made from 1/2" square sided chisels. Eventually my plan is to make a couple more from 1/4" bevel edge chisels.

It is easy to see the advantage with a straight chisel cutting at a skew on end grain. Give it a try, if you like what you get then maybe making your own is an inexpensive answer. If you don't get it, then don't waste the time or money.

In dovetail joints or trimming shoulders the skew from the tip slanting to the right to the trailing part of the edge is mostly used on the right side of the trimming operation. Guide on the trailing edge, not the pointed edge. This will be obvious when you use one awhile.

jtk

Derek Cohen
05-12-2015, 2:41 AM
Hi Ian

Skews and fishtails are primarily intended for acute angled corners, especially half-blind dovetails. They are used differently, and my preference is the fishtail, although it does depend on the side of the socket since they are wider than a skew.

The skew works by slicing waste, and this is done in a slicing movement ...

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Dovetailfishtailcutting3.jpg

The fishtail acts like a paring chisel, and is pushed forward. I find that this is easier to get to waste in the corner.

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Dovetailfishtailcutting2.jpg

Some will argue that they are unnecessary chisels, and all one needs is a 1/8" or 1/16" into the corners. I doubt that they make pointy ended ("London") dovetails, because poking the ends would damage the walls. A fishtail chisel is very useful when needed (frequently when I build drawers).

As examples go, the Blue Spruce are excellent, as is the Koyamaichi (below).

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Koyamaichi%20chisels/7.jpg

Regards from Perth

Derek

david charlesworth
05-12-2015, 4:30 AM
I find a pair of DIY, 1/4" skews, to be the most useful.

They get into the narrow sockets at the edge of carcase single lap and secret mitre dovetails. (See my recent DVD). ~;-)#

Some Fishtail chisels do not have sufficient slope angles and some are rather scratchy and dig in when slid along a glue face.

David Charlesworth

Jim Matthews
05-12-2015, 6:55 AM
I look at the pin sizes that make Fishtail chisels useful and wonder that the assembled
parts ever go together. Dropping a full drawer with pins this size gives me pause.

For me, a skew will do.

Pat Barry
05-12-2015, 8:00 AM
I look at the pin sizes that make Fishtail chisels useful and wonder that the assembled
parts ever go together. Dropping a full drawer with pins this size gives me pause.

For me, a skew will do.
When and where are you dropping your drawers Jim?

Prashun Patel
05-12-2015, 8:36 AM
If you do opt instead for a 1/16" straight chisel (as have I) don't make the mistake (as have I) of getting the Stanley Sweetheart. It's built fine, but the lands are squared so I learned the hard way what Derek speaks of. There are 1/16" chisels out there with steeper lands that are appropriate (enough) for reasonably skinny tails.

george wilson
05-12-2015, 9:08 AM
It is so easy to make your own fish tails,both in chisel or gouge form. Take some 1/4" square W1 or 01 stock. Get something to pound on. Doesn't have to be an anvil. Heat the metal to orange and hammer the end flat. It will easily make a fishtail shape.

Grind the tang end to a taper. Most often for a graceful shape,I will hammer the sides of the chisel into a swooped(swamped) shape,and file it up smooth. A fishtail can be made in a few minutes. Heat orange again and quench in a gallon of water,or vegetable oil(or automatic transmission fluid),depending on which metal you used. Don't try quenching in the wrong medium. . Don't use dirty,or used motor oil. Polish off the metal till you can see the surface,and heat to a medium brown color. You don't need a bolster on the tang since these chisels are hand driven,not hammered.

If you quench in the wrong medium,results may be usable,but not optimal. Quenching 01 in water,for example,may crack the tool. Or,you may get by with it,but the grain structure of the steel will be too large,and you will not be able to get the sharpest edge. Don't risk ruining your efforts to save a few dollars,or just to be in a rush.

Here are pictures of a set of fishtail chisels and gouges I made just fiddling around with a Mapp gas torch years ago. Sorry about the out of focus one. I can't seem to delete it. My old small,automatic camera had a mind of its own.

As you can see,there are several sizes,skews,and a dog leg. Once you get into making your own carving tools,you can do so on demand like Grinling Gibbons did in the 17th. C.. You aren't limited to what you can buy in the store,or the high cost of purchasing each one.

I made those simple handles as a design I could make quickly since at the time I was re handling about 75 old Addis chisels. The 2 shown with round handles were made another time,one is an antique,made by some old time craftsman,and the other one I made served as a test bed for one of my home made varnish recipes,with rosin tapped from my own pine trees. The brown is gotten by boiling the rosin in an iron container. Hot rosin eats iron and the ions turn the varnish a permanent forever brown color like some of the very old varnish on antiques.

If wanted,you can jam a steel washer onto the tapered shank of a chisel,like the one on the brown handled fishtail. Bother to file the hole square so it fits the tang,and it will be stronger.

ian maybury
05-12-2015, 1:06 PM
:) Guess i'll have to remember not to drop my drawers too...

Great to get a good overview of how the things get used guys - i can't name everybody. Wasn't sure if i was missing some sizeable application for them or not. Sounds like i have a DVD to check out.

I'd missed the point that the skew is potentially about enabling the chisel to cut on the skew so to speak - that it's not necessarily pushed like a fishtail.

I bought a couple of Koyamaichi fishtails with some paring chisels from Stuart in Japan before Christmas. As above the bevels can be done in the Mk 2 veritas honing guide (the extra grip given by the diamond nailfile jaws probably helps there), but flattening the backs is a bit more awkward. It's perfectly do-able, but needs care in how the chisel is held down/to stop it rocking since it's resting on such a small area.

Thanks for the tutorial George. It's useful to be able to tune a tool as needed living days from the nearest reasonable source of good tools as we do here, and it's easily do-able knowing how to treat the steel. (other than box store stuff) Looks like there's a pair of cunning hybrids in the first photo - skew fishtails… One option might be to keep an eye out for a few stock chisels suitable to modify....

george wilson
05-12-2015, 7:46 PM
Fine,attractive tools increase my inspiration when working. Most especially if I make them in the style of antique tools from the golden eras. So,I encourage everyone to make things like fishtails from scratch like I do. They really are very easy to make,and the freedom of not having to rely upon what the store has to offer is a very important issue to me. Plus,I really enjoy not paying $30 or $40.00 per tool. The amount of tool steel it takes to make a fishtail,especially W1 COLD DRAWN(available from MSC) is only a dollar or 2 per chisel. I actually prefer the W1 for these specialty chisels,because W1 will take a keener edge than 01(by a small,but sometimes essential margin). And,their durability is not an issue since their use is of a limited nature.

Cold drawn is not precision ground,and costs less since it is just extruded. And,I like its looks,too. The corners are not acute like precision ground steel,so I don't have to file them duller to be more comfortable in the hand. Just a little sanding makes it finish up bright if desired. It is quite smooth as purchased. I like it for making letter and number,and special figural stamps,too. I feel like I'm getting by cheaper!!(And I am!) But,not really reducing the quality of the tool. A properly tempered stamp will still yield thousands of impressions. All of the old stamps were made from W1 back when they were made nicely.

As for the fishtail skews,they were not intentionally made to be fishtail. They just got that way from hammering the metal out to make it wider at the cutting edge. However,having fishtail skews does serve the useful purpose of getting into acute corners even easier. So,all purposes are served!

Steve Voigt
05-12-2015, 8:03 PM
George, I love those carving tools, thanks for showing them. Definitely some inspiration there.

I'm with you on the W-1. I like to get it from flat-stock.com (http://www.flat-stock.com/). I got some 1/2 x 1/2 W-1 square bar from them, $20 for 3 feet. The 1/4 x 1/4 you mentioned is 5 bucks. Can't beat that. Their web site is kind of hard to navigate, but their shipping is lower than anyone else I've found, and customer service is great.

david charlesworth
05-13-2015, 3:59 AM
Perplexed by Derek's slicing action for skews.

I grind mine at about 1;5 so they work in single lap dovetails with a straight push.

David

ian maybury
05-13-2015, 7:17 AM
Tool steels unfortunately tends not to be locally available here George except in larger chunks for mould making and the like and subject to sizeable minimum quantities. I'll have to do some research in the UK. MSC have a network there for example, but i'm not sure whether or not they or anybody else do a cut to length/short stock length service. The consequence i guess of living in a small and mostly agricultural economy.

My initial thought about skews David was that they would need to match the slope of e.g. the pins pretty accurately so they would both clean along a corner, and bottom horizontally at the same time using a push stroke.

Then i saw the very sharp angles ground of some respectable commercial skew chisels, and with Derek's point had an aha! Which might or might not have been correct, or what Derek had in mind. The thought though was that lots of angle would permit moving the chisel manually sideways (or in multiple directions) like a like a paring knife to tidy up surfaces. This actually is the interesting bit about these tools - the question of how exactly do they get used....

george wilson
05-13-2015, 8:08 AM
Thanks,Steve. I book marked the page. If you click on Precision Marshall,it takes you to the cold drawn W1 as well as precision ground. I didn't figure the shipping,but the 1/4" square is $4.80 for 36". I don't know what MSC wants right off. I used to have a special relationship with them since I bought their large 17" Promaster lathe. But,I haven't needed to order anything for a few years except brass. And,I only order that from their subsidiary Enco when they have a free shipping deal!! Works out great when ordering heavy brass bars.