Thursday, January 17, 2013

Work In Progress/Chasing & Repousse

My wonderful new chasing tools have arrived from Valentin Yotkov! So I thought I'd do a small project to give them a shakedown cruise. Of course, they move like silk over the metal.  So, for Year of the Snake (the Black Water Snake), here's a step-by-step of the work so far.


I've traced my design onto a piece of 20 ga. copper, mounted in my pitch pot.

Hint:  I prepare the pitch in a 200 degree oven, thus avoiding the risk of setting fire to the pitch with too much torch. I can also run the exhaust fan to avoid any bad fumes.

Another Hint:  The pitch has to be cool and hardened before working the metal. Set it out in the snow or under cool running water for that.

See the pretty tools?  They arrived all sorted and labeled, and now I have a full range of types: liners, punches, planishers and matte tools. Warning --  Valentin says that you actually need to be able to make your own tools, since each new project may demand something different.

I followed my traced design with the small curved and straight liners.

After returning the pitch pot to the oven to heat the pitch just a little, I remove the workpiece and prepare it to mount, reversed, back on the pitch, to work the back side (repousse).  Don't anneal yet; you will want to work the metal against the lined areas, where it has become work hardened.

Hint:  To prevent the pitch from sticking too much, I prepared the back surface before placing it on the pitch with a thin coat of beeswax. Some people use Chapstick for this. Just be sure it's a thin coat, not too much.

Next Hint:  When you are ready to flip the work piece, and have removed it from the pitch, Goo Gone works to remove any pitch that sticks, so you don't have to burn off great globs. Lacquer thinner works, too, but the GG is less toxic. I do this step on the stove top, with the exhaust fan running; the fumes of pitch, copper and solvents are unsafe, and the burning pitch is very smoky. Think Siege of Troy. Note also that the solvents are combustible and you must be sure they have evaporated completely before exposing to open flame.

Here's the result of the repousse work, before flipping. I find this step to be harder than the liner work on the front ("chasing"). Good results demand you have the right size tool for the bump, since tool marks will show on the front, and if they don't contribute to the design, you will have to planish them away. Here, I am hoping the tool marks will contribute to the look of the snake, hinting of the ribs beneath the skin.

Now I will heat the pitch in the oven and remove the workpiece. This time I didn't use beeswax on the mounted side because I wanted plenty of support and no movement or hollow places in the pitch. I removed as much pitch as I could by scraping it away while still warm, and then annealed the piece, again under the exhaust fan.

Now the workpiece has been cleaned, flipped front side out, and mounted on the pitch once more.  I've used the liners again to refine the shape, added the eye pits, and used the matting tools on the background.  This makes the snake really stand out from the surface.


Stay tuned for the next chapter, which will involve an old army boot, liver of sulfur, hair-thin saw blade, hand drill, rivets, and a beach rock.

6 comments:

  1. My gosh...you're having fun! I wanta come play.

    ReplyDelete
  2. Such an interesting step by step!!! I'm going to look for these chasing and repousse tools! and the next chapter sounds yummy too!

    ReplyDelete
  3. Nice post. What fun. I liked the lumpy snake.

    ReplyDelete
  4. sweet deal..love that hammer...don’t think I could ever do this...I don’t even know what pitch is...

    ReplyDelete