Monday, September 4, 2017

Helpful hints from hello, wheez...cough cough...sigh



The Raven

As part of my never ending effort to be useful, I decided to try a post with some potentially useful information.  At least I think it's useful.  It's always possible that nothing I have to say is useful and that's why I spend most of my time talking to myself.      ...Eh.

A long time friend of mine from a former life who suspiciously follows me on Instagram asked for this information.  Well, ya know, he asked how I did this and I said I'd make a video.  What I actually said was, if I told him I'd have to kill him......so it's possible you will all have to die.  Probably not right away though. Anyway, I reconsidered and told him I would make a video.  Only, 1 - It would be 10 hours long and that's even too much for me.  And, 2 - I don't know how to make a video..... so the first part is just an excuse to cover up the second part.  Really though, 10 hours would be even more tedious than this explanation of why I am not making a 10 hour film.  Plus boredom would be a terrible way to die.  I decided to spare my fan and do a blog post instead.  So Bob, here's another post for you.

Anyway, back to the aforementioned somewhat useful information.  Chasing and repousse.  I will not, or probably not,  go into a long explanation of what each one is and how they differ.  Basically they are techniques that transform a flat piece of metal into a three dimensional relief.  Or something like that.  If you want the full explanations go to Wikipedia.  You can read that stuff there.  There are probably better places to find out about it but Wikipedia is concise. 

The definitions are less important to me than the technique.  Sort of.

Traditionally repousse and chasing were done in gold, silver and copper based metals.  I don't work in gold and silver and although I have some copper scrap, I mostly have aluminum scrap.  So that's what I have been using for my repousse and chasing.  One day I will graduate to steel and copper.  This is consistent with my life philosophy which is always start your day with gruel.  Otherwise it could go downhill.  Or sideways.  In other words, master every technique in the hardest possible material and then everything else will be cake.  Cake being dessert...and the last thing you eat in a day because you want to end on a high note.  Start with gruel.  End with cake.  Every day is a good day.

I feel like I should get to the meat of this blog now.  

As I said, I have aluminum sheet scrap.  I think it's 14g or maybe 16g.  It's scrap from a project I did probably 10 or so years ago.  I don't remember the exact gauge or alloy.  It's actually a bit scary because it's in jagged cuts off of the full sheets and the edges are sharp.  So I have these odd shaped pieces of aluminum sheet that I have been trying to come up with a use for.  My situation changed and I decided to do some repousse and chasing.  

Let me walk you through my process.  If you want to try this, you will need some things.  I'm just going to make a list of the things I think are useful or necessary when doing chasing and repousse.

  • A flat piece of metal sheet and an understanding of annealing and work hardening metals
  • A way to anneal the sheet.  I use a propane torch because I am working pretty small
  • A not hard surface.  This one is a little tricky.  There are a lot of things that can be used as backing.  Since I am working small, I use a pitch bowl.  There are several types of pitch and the type you choose is based on how you work.  My pitch is a combination because I keep trying new pitches.  But if you are just starting and want to try this without a huge investment, you could try using carpet or rubber or wax as a backing.  I met a guy last year who does all his chasing in wax because it gives the way he wants it too, and he thinks pitch is too hard.  The reason I use a bowl, rather than a box or some other thing to hold my pitch, is that I can move it and angle it as I work.  Dang, I gotta go take a picture of this.  BRB  hahahahah 
    Pitch bowl on stand
  • A hammer with a large flat face.  I have several hammers.  I use two most often.  I have a cheap cobblers hammer and I have an expensive chasing hammer.  They cost me about the same amount each.  You can get a cheap chasing  hammer for less than $10.  It will work fine and give you a chance to not spend all your money on tools that you will toss in a corner when you get frustrated and give up.  Not that you will.
  • Chasing tools.  Oh yeah.  That's a wide open thing.  I made most of mine,  You can buy them but it's pricey.  I don't think you need a lot of tools to start.  To begin you could probably get away with a liner, some kind of pusher and a planisher.  I made my favorite liner from a small cold chisel that had seen some rough use.  I have a doming block from HarborFreight that I use for pushing.  It may not work on other metals.  And I made a planisher from another broken chisel.  I do have a bit of tool steel around the shop, so I have made a few chasing tools over the last year.  Each situation will dictate the tools necessary, but for a basic form and to see how metal moves you can start very basic.  You could start with just a planisher that also pushes.  
  • Safety glasses and ear plugs.  Don't be an idiot.  
  • Good light
  • A surface to flatten the work between processes and when you are done.  I use an anvil.  
  • A soft hammer to flatten the work as above.  I use a cheap wood mallet, but some day I will probably invest in a paper hammer.  

I think that's all the tools.  The first thing you must do is anneal the metal.  As part of that process I heat the pitch so that the metal will stick to it and I can work.  Once the metal is stuck to the pitch, I can draw the figure on the face of the metal with a liner. That is the entire first step.  Easy.
All the tools and the Raven drawn with the chisel in the aluminum sheet. I used a curved and a straight liner and my cobblers hammer.

Just beginning the repousse using doming tools
Next I remove the metal from the pitch (this takes heat) and turn it over and reattach it to the pitch. This is the beginning of the repousse phase.  To be honest, I am still working on this.  I need to get better at not over pushing the metal and seeing the negative form.  While you are doing this you are working on the back side of the piece. I also work with the pitch warm.  I never want to do any work where I'm not sweating all the time.

Ready to be removed from the pitch and be turned over for chasing









The raven has been reattached to the pitch and is ready for chasing










Once the repousse is complete you need to heat the metal again to remove it from the pitch and dress the pitch by reheating it and moving it around so it's ready to hold the work again.  I often anneal the work again at this point.  I also put pitch in the back of the work so that it is fully supported for chasing.  

The aluminum needs to be flattened
The Raven has had the detail added.  I should have taken more pictures of the chasing process. This is after it has been flattened on the anvil.
Chasing is the most fun part of the process because that's when the work takes on it's final shape and begins to really look like your vision.  This is probably the most time consuming part.  I'm not entirely happy with this raven, but that's because I made a mistake in my thinking.  I am always learning so I hope I won't make that mistake again.  Usually by the end of the chasing, the metal has broken free of the pitch.  If it hasn't then you need to heat it.  If it breaks free too soon, you will need to reattach it.  
The Raven lifted off the pitch
The raven after the curve in the aluminum has been removed.

This should be fun.  Keep in mind that you are sculpting directly into the metal sheet.  You should work it until it looks the way you want it to look.  


The impression of the Raven in the pitch.  You can see some of the different pitch colors I use.
Oh yeah, your hands will probably hurt.  

And Bob, thanks for asking, I have all new teeth now and my jaw is mostly healed.

Back to work
j

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