New portable forge

I decided to construct a small portable forge to be able to work at home or away from the workshop. Its built out of an Illy coffee can, diameter 20cm, length 30cm. Lined with 5cm of refractory blanket.

I also tried to make a smaller propane burner, instead of the 3/4 inch Zoeller sidearm burner I use on my larger forge. This one is made out of 1/2 inch pipe, with a 0.6mm gas tip. I had some trouble making the air inlets without a drill press, and I will probably have to go to a machinist to drill them properly, but for testing they suffice. The rules of thumb for such a burner are a length at least 9 times the diameter of the pipe, a flare at the end, and an air inlet area equivalent to the opening of a 1 inch pipe.

After some tweaking here is a first acceptable flame. The good thing is that this type of burner runs well even on very low gas pressure. Also the 0.6mm tip used instead of the 1mm for the 3/4" sidearm burner should keep gas consumption to about 1/3 of the larger burner, which will mean much lower running costs. I should also built a sleeve around the air inlets to be able to control air intake and oxidizing-reducing burn.

On a first test the forge went up to 920C in 1-2 minutes, but I still have some doubts as to how well the forge will handle such heat. More testing will be posted shortly...

Proper Japanese style hammer, at last.

A friend made me a gift, a machined hammer head, made of Uddeholm Hotvar steel, which I finished, heat-treated and made a handle for.
Its 4.3cm wide, 13cm long, with a 34cm handle made of an old oak plank. Weight of hammer head is 1310gr, and together with the handle 1490gr. Perfect!

What was particularly interesting was the heat-treatment. Heat up to roughly 1000C, quench the first 5cm in soapy, warm water for 30 sec, and then let the heat of the remaining piece dissipate and do the tempering.

Athame finished!

Finally finished the athame! A note on materials, the wood is iroko blackened by burning it, in the Japanese sugi-ban manner, and the steel (such as it is) was tempered for 1 hour at 320C to get the blue-black oxide.

A big note on mystery steels! Don't use them! 

At least not unless you do a quench test, which I did not. Hence, the old handmade rasp I had found, turned to be unhardenable, though I tried both oil and water quenches. For this particular piece its no big deal as it a ceremonial item and will not see any cutting use, plus the 320C temper would have softened it a lot anyway. But still... its a shame.

     

Anyway, another lesson is that when I do decide to make a proper knife shaped like a yari, I will run into countless problems keeping it straight in the quench. This one took a wild upward curve, which I removed easily since it did not harden, but I really do not know what I would have done otherwise. In any case enjoy!

 

Inspired toolmaking - Hammer

 After watching the previous inspiring videos, I decided to finish up some older tool projects and maybe start some new ones.

The following is a rather old project, which I had never finished, namely a Japanese style, weight-forward forging hammer. Is is basically a piece of AISI 1060 steel, with a round hole machined at one end, and then heat-treated to about 50 HRc, the same hardness as my anvil, or maybe slightly softer.

 Of course after finishing it, I realized how simple, clunky (though it still does its job well) and inelegant it truly is. Hmmm, better design next time. For now here are some samples of proper Japanese style forging hammers, found at:

http://www.mehr-als-werkzeug.de

thejapanwoodworker.com

and http://owenbush.co.uk/tools

Inspired toolmaking!

Just came across this video (which is actually the first in a set of three) about a small group of Latvian
craftmen, Neeman Tools, building hand made tools, like knives, axes and chisels.
The videos are excellent, and their site has been overwhelmed with orders... which is perfectly logical
as they exhume the true spirit and joy of good craftsmanship. Enjoy!


Just to be fair, it came to my attention that John Neeman, the bladesmith after whom the previous site
is named, went out and established his own firm, Autine, which has come out with another video. Equally impressive, though I feel the speak-over is unneeded...

Athame WIP

A friend ordered a ceremonial Athame, which I have started forming out of an old handmade rasp I found. Seems to be coming out nicely, with a triangular shaped cross section, much like a Japanese yari.
I will go for an olive oil quench (instead of water) both because it's a mystery steel, and  to avoid breaking the blade, as such double edged blades are prone to. Then temper, polish and retemper-heat color to a purplish black, as that is the color an Athame is supposed to have.

I am currently struggling with the shape of the hilt (again fashioned from a piece of Iroko hardwood I found somewhere), trying to give it some organic shape, inspired by master knife maker Gerhard Wieland. By the way if you want to take a look at his incredible work try http://www.wieland-der-schmied.de/03_1_messer.html.

Eye candy - palladium-silver mokume wedding rings

 OK, just received some professional photos from the wedding, showing the previously posted palladium-silver mokume gane wedding rings in a light and setting they deserve. The wedding crowns were also hand-made out of shibuichi and silver wire; simple yet elegant. Enjoy!

By the way, I am building a commercial site, where items such as these will be up for order and sale. Stay posted...

Increased Blog traffic

I have been keeping this blog for about 2 years now, and suddenly there has been a 4 fold increase in
views. At first I was suspicious, people just tell me to be grateful.

Please do not hesitate to leave comments, and tell me what you like, don't like, and what you'd like to see more of...

Black metal

It has been really hot over here to light the forge, hence the long pause in posts.

I have also been away on other business, but rest assured that I am preparing something major,
which will be announced shortly.

For the time being here are a couple of thoughts on a fascinating subject, Black Metal.
It seems that developing a metal with a black color that will not corrode, rust or discolor has been a
self imposed task of metallurgists since Antiquity.

Indeed, the Egyptians, Myceneans, Greeks and Romans had developed a series of mysterious alloys, Corinthian or Black Bronze or Aes, Hepatizon (from the greek word Hepar 'liver' indicating its color), and others.

Pliny gives us a few hints, but the credibility of his account is questionable, as the composition of such valuable alloys must have been a well guarded guild secret.


Nowadays, we can get more information by analyzing extant specimens of such black colored metals on antique decorative artifacts. It seems that a variety of alloys of copper, silver and gold were utilized to achieve the color. Here are a couple of links for the more academically inclined:

Colourful Corrosion: Black Bronze and its Enigmatic Patina
http://pia-journal.co.uk/article/download/14/27

Laboratory Investigation of Inlays and Surface Treatments for the Decoration
of Copper-Base Alloy objects from the Imperial Roman Period
http://orbi.ulg.ac.be/bitstream/2268/34863/1/Article%20Archaeometry.pdf

There is also another large group of alloys of greyish to black color developed in the East, and surviving in Japanese traditional metalwork, namely the irogane alloys, Shibuichi, Shakudo, Kuromido, etc. These are again copper, silver, gold and sometimes lead or arsenic alloys that patinate to a variety of blackish hues.

Again here are a couple of papers on the subject:

Japanese irogane alloys and patination – a study of production and application
http://shura.shu.ac.uk/971/ 

Japanese Shakudo: Its History, Properties and Production from Gold-Containing Alloys
http://www.springerlink.com/content/n2006277t705624g/ 

Finally there is a newer pattented, German industrial alloy, named mujodogane which supposedly takes on a permanent or semi-permanent black color. 
http://mujodogane.erlebe-es.de/synapsecore.php?mainnode=synapsepath/Informationen_ueber_Mujodogane
The site offers little info on what the alloy contains, other than naming it a silver alloy.
Now as much as I would like to believe it, the above bibliography speaks against any silver based alloy being black, but since they do not give us the composition, I cannot dispute the claim, even though I am personally, highly sceptical.

I guess it is time for me to start experimenting, as a black alloy for mokume-gane that does not corrode or discolor would be a true delight. More on the subject in future posts.