forming a chisel tang & bolster

[Steve Voigt]

Hi all,

Please forgive a stupid newbie question. Can you click on the image below and tell me if this is possible? If I take the bottom 2" of a piece of 1/4" x 1" stock, can I edge-hammer it into a square section roughly 1/2" x 1/2"?

 

It seems like going the other way--taking a piece of 1/2 square stock and drawing out the top 6"-- would be much more labor intensive, but I don't really know that.

 

The goal is to make a tang chisel with integral bolster, but I'm just trying to think about the first step.

 

Thanks!

 

 

 

[ThomasPowers]

Take a piece of graph paper and draw out the two cross sections. Do they contain the same amount of squares? then yes it's possible.

Another method is taking some modeling clay and roll it out 1x1/4" and see if you can form what you want from it.

For something this simple you could just doodle a 1/4" x 1" box and put a line every 1/4" giving 4 1/4" x 1/4" boxes. next draw a 1/2" x 1/2" and divide it into 1/4" x 1/4" boxes they have the same number of boxes and so you can change one into the other.

[Steve Voigt]

Hi Thomas,

Thanks for replying. Sorry if I wasn't clear. I wasn't really asking about the dimensions--I worked that part out*--but about the technique, if edge-hammering will produce the desired result. But it sounds from your reply like think it will work, so that's encouraging.

 

* (a 1/4 x 1 cross section has the same area as a 1/2 x 1/2 cross section, so the dimensions should work, and they are just approximate anyway.)

[ThomasPowers]

I you are trying to make it exact you will need to upset it a little as you go along to deal with the edge hammering lengthening it a bit as well as swelling it. Me I would probably make it whatever it wants to be when I hammer it on edge and go with that.

[Steve Voigt]

OK, thanks. Sounds like it is worth a try anyway. I will experiment with some 1018 before I go screwing up a piece of tool steel.

[ThomasPowers]

Good idea. I assume this will be a tanged chisel? Have you read Weygers' ideas on forging wood carving chisels in "The Complete Modern Blacksmith"

[Charles R. Stevens]

For practical perposes, its a wash as to wich is easyer. Depends on the stock on hand. The first step either way is to isulate the blade from the bolster. Then you either draw the blade down or upset the bolster, if you drow the blade use your cross pein (make shure it is dresed to the apropriate radius or you will suffer all kinds of dings. If you up set the bolster use the face, again properly dressed. Make sure you have a good heat reagardles. When you use the moenky tool to square up the shoulders for the tang will slightly upset the bolster.
Take TP,s suggestion and use clay to work out the steps especialy playing with using fullers and set tools to isolate shoulders. Unless you are good at imagining how the steel moves. You might consider using automotive spring or mexican rebar (the stuff tends to be hard) to prototype as it is much harder to move than A36 or 1018. Be especialy carful with rebar as some of it will air harden

[Steve Voigt]

Hi Thomas,

Yes, a tanged chisel. I'm including a sample image below. Do you have any thoughts on forming the bolster?

I have the Weyger book but haven't found anything on forging a bolster.

Thanks for your help!

 

[Steve Voigt]

Charles,

How do you isolate the blade from the bolster?

[Charles R. Stevens]

Use a fuller, or if you have the hammer controle use the rounded edge of your anvil and yourcross pein. You will do basicaly the same thing on the tand side but you either use a side set or fuller and moeky tool or a header.

[ThomasPowers]

Isolate a bulge and finish it in a die if you are going to do a lot of them; or use a monkey tool; or make a ball and hot rasp one side flat, or...

 

I was not thinking of a bolster WRT Weygers but his theories on wood carving chisels design.

[Charles R. Stevens]

If I was home I'd draw out a story board, hard to explane the steps with out wrighting a book, and with an Arizona/Okie accent and horable spelling I might not get the point accros anyway, lol.

[Frank Turley]

Charles, The new posted photo of you is too much! LOL

 

I've used round-sectioned W1 drill rod to forge such chisels. I use edge-to-edge blows, the radius of your hammer face matches the radius on the near anvil edge. The drill rod has around 1% carbon for good edge holding. It comes in 3 foot lengths from Travers Tool, MSC, or McMaster Carr. A short-run, square ended monkey tool can be pieces of mild steel arc welded together. If you have a striker, use fullers and/or set tools. A guillotine can be fabbed for fullering and set tooling, if working by yourself. If you cross-peen the blade to obtain width, do as Charles suggests; use a semi flat peen, not a full half round one, or you'll have more cleanup to make the surface smooth.

[JNewman]

I have made chisels and carving tools from round W1 and A2.  W1 is far better if you don't have a power hammer and experience .  Round or square is much easier to forge bolsters from than flat stock. Flattening out the stock is easier than fighting the 1 in 3 rule to build up mass for the bolster.  Look up spring fullers for isolating the stock.  For smaller chisels and carving tools 2 spring fullers works well.  One made from 5/8- 3/4 round and one made from 1/4 x 1" flat on edge. 

 

Take your stock and isolate a short piece at the end (length depends on diameter)  draw the isolated end out to your tang.  Don't fuller all the way to your finished size leave a little extra stock to be forged down to clean up your fullering.  If it is too long cut it off.  If you want to use a monkey tool now is the time to use it although grinding or filing the shoulder when you are all done your forging  works well too.  You now have a thin tang so you have to be be careful not to burn the end during the next step.   Use the larger fuller to create the outside of the bolster.   You can now flatten the round to flat while tapering the stock from the fuller into the width of the flat chisel.  You can also fuller again using the larger fuller to give you a transition from the shank in front of the bolster to the chisel blade.   Be very careful not to get any clod shuts in your forging as they seem to turn to cracks more quickly in high carbon steel. 

 

Try forging a couple of bolsters and the transition to the blade in mild steel before using your more expensive tool steel.   If you make your first one out of tool steel you will likely decide to draw out the the blade even if the first bolster is not so great.  If the bolster breaks off after all the work of drawing out the blade you will not be happy.

[Charles R. Stevens]

Frank,
that Is after a month of building fence this summer. I grew up 20 min north or Phoenix, so I may have imigrated to Oklihoma but I'm a desert rat at heart.
I tend to use a half round hammer, as in a hand slege that is half round on one end, insted of a pein. I have both strait pein, cross pein and ball end versians for drawing out.
Now if Glenn, Steve or some one will take pitty on me and rotate me right side up...
Im geting a crink in my neck!

[Steve Voigt]

Thanks very much for the advice everybody. I'm definitely going to try this out with some 1018 before I do the real thing.

[ThomasPowers]

Charles, I thought it was just a picture of you standing in a field on your AR hill farm.

[Charles R. Stevens]

That, Master Powers is certainly a posibility. Lol

[rockstar.esq]

I could have sworn my Weygers book includes a passage about making a ferrule/bolster that's made to slide up on the tang.  The square tang cuts the round hole and locks in.

 

Just looking at the design makes me think that a funnel shaped tang like framing slicks have would be a potentially better approach for a struck chisel.  The tapered tangs seem more appropriate for paring chisels.