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A Bramblebush Workroom Project
Repousse`/Chasing
A compendium of miscellaneous information
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Page 01
Jan. 1, 1999 - ....> I had the good fortune to be given a little suitcase full of 1950s American > octagonal steel rod, most of which had already been made into fine chasing > tools. That kind of steel --
An excellent source of steel for small chasing tools are old or broken up sets of letter stamps. They are fantastic for this sort of application and can often be found at places like flea markets etc.
You can even buy new sets from places like Harbor Freight and still come out ahead in terms of cost for the metal. Don't throw away your old worn out files either. Anneal them and grind or forge your shapes then retemper to a softer state than the orginal for toughness rather than hardness. Of course files are usually too big for some work but fine for others.
Concrete nails are hardened steel and they work okay and are a bit on the small side I guess but I think you can get 1/4" dia. nails though. Heat, upset the end then reshape and you'll be fine with those.
Chris Ray
Jan. 2, 1999 - If you are walkin' by the tracks, look out for date nails. These are square nails @1/4" in dia. that get hammered into wooden ties (sleepers, Bri) with the year the ties were laid cast into the head of the nail. When the ties are replaced the date nails often fall out and are left lying. They are a little short, a little soft, but they make wonderful utility tools, that is they can be reshaped on the spur of the moment. Tie plates make great bench anvils, they have stake holes already in 'em. Railroads are a good source of all sorts of old iron, just don't put yourself in a position that could be seriously judged as Trespassing.
Robin the Hammer
Jan. 2, 1999 - Bill Manfredi, the guy who taught me about chasing, only said to mix pitch with a little wax and ashes. Then he prepared me a pot out of his vast supply of pitch which I use to this day. We poured it into an aluminum lamp shade, the hole stopped with a jar lid.
Then he screwed three pieces of two by four into a triangle about 1' on a side for a sliding base. I can reach any part of my work from any angle and never touch a wingnut or a clamp, and I have a more solid base than any shotbag could give. I can hook the triangle over a short stake and hang it over the edge of my benchplate for an angle. It's simple to make and flexible to use.
Over the years I have replenished the pitch a number of times, and I don't trouble too much about the mix. I use bunker-C right out of the can. When I heat the surface, I burn it enough to be sure of the ash content. When dust and wax fall on the surface, I just melt them into it. I prefer sticky pitch, so this is sufficient for me.
Robin the Hammer
Jan. 2, 1999 - ...>>I have done high relief on fine silver as thick as .050", and on 18k as thick as >.040. Sterling and brass are more brittle, and take a lot of annealing, but >bronze can be fun
My experience has been that sterling is sort of a bear to try to work with on a small scale when dealing with these practices. It's pretty rigid, although there are lots and lots of objects made of sterling that have both high and low relief embellishments. I've seen Gene and Hiroko Pijanowski using what I believed at the time (and still believe) to be fine silver which is much more pliable, really more akin to the workability of copper.
I always liked bronze sheet to practice repousse and more particularly chasing on. While still remaining fairly rigid, it seems somewhat more formable than I ever found sterling silver to be.
On smaller pieces, I would generally work with materials ranging between around 24 gauge (.020") to 18 gauge (.040"). I could certainly see using thicker metal on larger objects, particularly if high relief is going to be imposed on it. The type of metal used and the inteded use of the resulting object also need to be taken into account in determining the thickness of material to be used.
Keith Farley
Jan. 2, 1999 - ....> you need to slllooow > down the cooling process for mild steel by burying the red hot piece of > sheet in a bucket of lime,or warm sand or vermeculite whatever ya got > that will slow down the cooling and insulate it to hold that heat in > there for as long as possible. hope this helps!
Awww....you don't need to wait that long Bill. For sheet forming just remove from the fire and cool at room temperature and then get right back to work.
Actually I have a real neat quickie cooler that does a terrific job so I can continue my work without waiting for an excessive amount of cool down time.
Sometimes we overdo this sort of annealing thing more than necessary, since the process is more critical with carbon steels than mild steel. The more carbon in the steel, the longer the cooling process should be. That's what I like about mild steel, you can abuse it and it still loves you back.
Here's what I do. After removing a sheet from my updraft forge or torch I allow the steel to cool down a little bit in the air then I grab my leaf blower, yup, one of those hand held thingies that you blow all your fall leaves over to the neighbor's yard with. I removed the long nozzle so I have a short snouted super duper quickie cooler to cool off the metal rather than dunking it into water for the final cool down. This is much neater than splashing water all over the place. The metal cooled this way is annealed just fine for continued work. No fuss, no muss and the metal is dry to the touch....and cool....and annealed.
Chris Ray
Jan. 3, 1999 - ....> Does anyone know what is going on in the steel at the anneal > temperature?
Well steels can do that too but are a little different. You are not really doing an anneal you are just tempering or stress relieving the work. As you move the metal it builds up stress to yield and you work harden it by pushing the crystals around locking up grain boundaries with dislocations etc. When you heat steel it gets weaker at high temperature and the yield stress relaxes to what the material is capable of at the high temperature which may say 5 or 10 percent of what yield is at room temp. The crystals also get a chance to reform etc.
You can also do a true anneal taking the material up in temp till the steel becomes nonmagnetic i.e. it changes phase. Then slow cool. Depending on the alloy you may have to hold at some temperatures to get the steel to change all to ferrite (the soft stuff). At very high temps it is austinite (non magnetic) If you quench it fast you freeze the material in magnetite (very hard) Slow cool gives ferrite. Most of the time we have blends of ferrite and magnetite or tempered magnetite. All the phase have different properties like specific volume.
I know this is not all technically correct but I keep my cartoon version of technical things so my simple mind can cope with it. Apologies to the real metals people for the simplifications and all the English majors for the sentence structure and spelling!.
Brad Piatt
Jan. 3, 1999 - ....Today I'm initiating a new series of mini workshops on line that will be updated weekly. The first portion of this deals with the techniques of hollow forming copper for sculpture so I'll include the link here:
http://www.artmetal.com/chrisray/process
Chris Ray
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