Friday, December 31, 2010

Two new forges

After the demise of my last forge, I decided to redo them both. Luckily I found some Kaowool Cerachem 1430 C rated ceramic blanket and Kaowool Hardener (which is a liquid that hardens the surface of the Kaowool, so it does not decompose and leave fibers in the air) and some proper firebricks.

The first forge is a vertical Don Fogg type which I insulated with 5cm of ceramic blanket, and will be using for knife and sword forging, and maybe steel making (I might have to build a sturdier one though, if I want to do really long burns in it). By the way the metal container is an old oil drum I found at a scrap yard.

The second is a remake on my earlier, recycled water-heater, horizontal forge, which I lined with about 10cm of ceramic blanket  and which I'll be using more for welding mokume billets and welding in general. Even though the burner is not aimed ideally (I understand that it should run tangential to the inner surfaces, so that the flame forms a vortex) the domed top does make the flame turn, leaving fewer cold spots.
In the back you can see the torque plates for the mokume gane, and a small crucible for casting shibuichi; more on that later...

Tuesday, December 28, 2010

Failure by fire...

Well, things were going pretty well for a while, so for the sake of cosmic balance I had to suffer a setback. I tried making some homemade steel - oroshigane, the way Michael Bell taught me in Oregon, and things were going pretty well. Filled a graphite crucible with about 2 Kg chips of antique wrought iron and charcoal dust, sealed it with fire clay, and put it in a vertical forge. 


Managed to bring up to 1050 C degrees with just my atmospheric burner, but alas...


... after about an hour the whole forge was on fire, so I had to abort everything. The reason; back before I met master Bell I had built my two forges with the materials I could find at the time, namely rockwool and a fire cement used for building fireplaces. Well, it is proven now that these materials cannot stand forge temperatures. So I have to go out and look for some proper ceramic blanket and refractory cement to insulate my forge...

....better luck next time.

Thursday, December 23, 2010

Mokume gane second attempt

Second attempt with 21 layers of alternating silver nickel, bronze, copper, bronze. 
Found out that this particular bronze melts at around 850 C, so I used it sort of like a glue between the other two metals. 
What I learnt is that temperature control in the forge is not as important as keeping a really reducing atmosphere in there to avoid oxidation and hence delamination. Also you really have to dig deep into the layers afterwards to get an interesting pattern.

Thoughts on next time, find a proper way to polish and patinate, as well as maybe use different thickness in the metals to get a more active pattern. Also maybe get a rolling mill...? (Gosh, more money to spend on machinery... this has got to stop. Or maybe I have to find a way to sell mokume gane to jewelers in Europe...)

Friday, December 17, 2010

Mokume gane

I just tried my hand at making some mokume gane. Its still at an experimental phase so it has just a few layers, but it came out surprisingly good!
A press is pretty useful for consolidating the billet, and generally just pretty as you can see below.

Started out with 12 layers of copper, bronze and nickel silver, which had to be meticulously sanded and cleaned.

Stick them between some stainless steel torque plates, in a controlled temperature forge (by the way, this is my horizontal forge on a modified sidearm venturi burner going up to 1140 C at only 30 psi or 2 bar).

And voila, after some press work, forging, and sanding a pretty acceptable mokume plate. You might notice that no bronze appears in the final product, that's because bronze melts at around 600 C while the billets needs about 900 C to weld, so upon pressing it the, by now molten, bronze was squished out of the billet (ending up like really thin bronze wafers or chocolate chip like forms on my shop floor).

So the next try should maybe be without bronze and with a lot more layers... 
I'll keep you posted. By the way, for those of you that have no idea of what I am talking about, google mokume gane on wikipedia, 

or have a look at the following article "Mokume for the Bladesmith"

or another good post, from which the first image in this post originates

Addendum: I have come a long way since this post, but I see people being led to this one by google. For more info and details, you might want to check my other mokume gane posts such as the following:

Thursday, December 9, 2010

Caterpillar yellow!

Well just another post on my progress, which is Seriously Slow (well I am just ordering or constructing parts for a new belt grinder, so I have little to show). 
In the meantime took some time to spray paint my press. The only yellow available was Caterpillar yellow, so here it goes. 
The Dexter-like setting was necessary so I would not cover my whole shop in a light layer of yellow...

Dexter lurking around the corner...?

Finished press. Cute, no?