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pitch question
alex b. -
Wednesday, November 28, 2007 - 2:10am
more questions about repousse, chasing. is the pitch reusable, i haven't seen any mention of this which now that i write this probably means "no".  A pitch for pitch
visitor -
Wednesday, November 28, 2007 - 7:40am
First of all. There are other things that can be used to back-up the metal you are going to chase and repousse. Wood, rubber, cardboard, carpet, etc.... A local artist used roofing tar to repousse the "Stations of the Cross" and much of the decorations at a local church. Artist/craftsmen are very resourcefull folks. Pitch has that wonderful quality of being both giving to the metal being struck and holding firmly to the metal so it does not bounce around as well as resisting to allow the metal to remain where it is where it is not struck. Sticks rubbed together can start a fire and using a match seems so much easier. You can use pitch on any metal that can be worked cold. At high temps the pitch melts and looses it's wonderful properties until it cools. Fred Pitch is reusable unless you are careless and burn it. » reply  Size Limit for repousse
Fred Zweig -
Wednesday, November 28, 2007 - 7:56am
The limit is your imagination and patience. The statue of liberty was repoussed out of heavy plates of copper and then rivited together. Not a shabby job. When you are working at the scale of a human body it is possible to do much of your shaping in the air without backing. I did a lifesize torso and neck using nothing but a stump to hammer on and shaped wooden stakes. This was just the front of the top portion of the body. I wish I had taken photos of it before trading it for a table. I suggest that you acquire a copy of the book "Moving Metal" by Adolph Steines. The book deals with the larger projects and the making of tools and alternates to pitch. Fred Zweig » reply I seem to remember that it
visitor -
Wednesday, November 28, 2007 - 6:35pm
I seem to remember that it is 20 gage copper that is used for the Statue of Liberty. That is not very heavy. It is about the thickness of a dime. marilyn » reply  At the risk of being
Rich Waugh -
Wednesday, November 28, 2007 - 9:31am
At the risk of being off-putting to the traditionalists, let me suggest that if you're going to attempt to do life-sized figures, you invest in some air tools. A medium-sized chipping hammer will move a tremendous amount of metal in short order. You'd have to make custom heads for it, of course, but that's certainly no problem and works very well. And, naturally, you need a good-sized air compressor to run a chipping hammer. Those things pull somewhere on the order of 18-30 cfm @90 psig, depending on size. As mentioned, larger pieces can be done in air, as the mass of the metals itself provides much of the needed resistance and inertia. For larger work such as this, I'd recommend using metal no less than 16 gauge and I'd probably go to 12 or 14 gauge for something as soft as copper. For steel, try to get what is known as low-carbon, deep-drawing steel. It will work harden much more slowly, and tolerate greater movement without fracturing than A-36 structural steel will. One issue with working really big pieces is the problem of annealing. You need a large fire for copper, because it conducts so well that the whole thing needs to be heated at once. For steel, you need to be able to cool the piece slowly, which is accomplished by burying it in ashes or wrapping with refractory blanket material. Again, a big fire to get it hot enough to anneal. You can do repousse work on any metal that can be moved by mechanical means. Some work better than others. Copper is nice, silver is better, gold is fantastic, pure titanium is nice, steel is good if low enough carbon, stainless steel is horrible, brass is variable depending on the alloy, silicon bronze is very nice, phosphorus bronze is impossible, lead is easy by dangerous, tin is good, the list goes on. » reply  As mentioned, larger
Gene Olson -
Friday, November 30, 2007 - 3:55pm
Rich, The Herman statue in New Ulm MN. 38ft tall copper clad steel frame figure was done in 32 oz (~18ga) except for some smaller ornaments which were 16oz. I think the Statue of Liberty was like 48 or 64 oz. (~16 ga or better). 32 oz should be fine for most work unless it is going to be constantly stroked. The original zinc statue I worked on this summer was only about 20 ga. our patch was 1mm which was much thicker and harder to work. That statue was 12.5 ft. made by the same firm that did the New Ulm, Herman statue.
Gene Olson Sculptor Elk River, MN » reply  Short answer, yes the pitch
marilyn -
Thursday, November 29, 2007 - 9:24pm
Short answer, yes the pitch is reusuable. It stays in its pitch indefinatly. If you melt it and pour it into something else, just reheat, melt and put it back in the pitch bowl when done. marilyn » reply Repeated heating and
Gene Olson -
Friday, November 30, 2007 - 10:09am
Heating and reheating burns/evaporates the volitiles out of the pitch mixture. Chasing pitch recipes include oils, resins, and fillers. The oils and some of the resins tend to burn off over time and the pitch gets stiffer, less sticky, and more brittle. Some of the workability can be restored to old pitch by heating and stirring in small amounts of say canola or cottonseed oil. Gene Olson » reply |
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is there some thing else usable instead of pitch?