by Gene Olson
scaling to fit
transferring your design to the tin
forming - repoussé and chasing
piercing - punch, chisel, and saw
appliqué - rivet, solder, glue
finishing - paints and patinas
I have several books here on tin and copper sheet work. They show various ways one could make a little metal box and while it looks simple enough, making parts for a tight fit is quite a challenge. Once one gets the hard part done one tends to get timid, "Oh my! If I mess up decorating this, I'll have to start all over. . . Oh dear, what if . . ." Thus this project, practicing the fun part so when you go to decorate that tough to make part, you can approach it with confidence. (The hard part may be finding someone to eat the candy.) There are a lot of ways that you can add design and detail to a sheet metal piece such as piercing, forming, adding stuff, finishing and sealing , or combinations of all of them . . . In this article we hope to give you a primer on these, something to get you started. Once you start, where you go is your adventure.
What should I do?
What should I do?
What should I do? . . .
Stop worrying and get started on something, anything.
There was a study done once at an art school, half the class was given the word, "You will be graded on the quantity of work you turn in" and the other half was told, "You may turn in as much or as little work as you wish, but you will be graded on the quality of the work produced" In the end, it was found that those who made the most work did the best work. High concept without understanding of craft, without practice, realization of success and failure, just didn't make very much good art. Another part of this is, mistakes . . . we all make them. It is how we recover from them, capitalize on them, reinvent them that spells the difference between success and failure.
And failure? not here, we are all learning. This is still just an Altoids box that was headed for the bin in the first place. It just took a side trip while you beat the heck out of it. Pick up another one, and begin again.
Drawing your own or finding something, the important thing is to get started. Practice is what will make your own design sing once you find it, so it doesn't really matter what you start with. You will change it as you go anyway and make it your own.
At this point pick something simple, draw a simple flower or maybe a single letter for a monogram (here are three alphabets that you could use.) If you have a computer, there are probably dozens of workable images in your clip art library. Go ahead and use them.
Tools and Techniques:
Tools need not be expensive or fancy, a file, a funky old screwdriver, a nail, a spoon, a piece of 2x4, These can get you started. And since the material is relatively soft tools don't have to be the best tool steel to give good service. (Making real nice tools is a satisfying pursuit in it's own right, and I recommend it, but for now let's get started)
Tool Lesson # 1 - Wear ear Plugs - Pounding on metal makes an unholy racket. Wear ear protection. Hearing loss is a real pain
Tool Lesson # 2 - Wear eye protection, steel chips off tools or chemical burns are no fun and can put a real crimp in your style.
forming - repoussé and chasing
(Gargle and then take that R from the gargle and say) Ray, add Poose (rhymes with goose) add Eh? (Kind of like a soft cough) now say it faster, Ray Poose eh? now say it like you don't really care, that's pretty good, almost French, and French for pushed from behind. Chasing is similar, but it is done from the front, and usually in finer detail.
In either case, your tools are rounded, dull. They are not chisels, they are like tiny hammers. The object is to move the metal from where it is to where you want it. That is much the same as in most any forging operation.
Forming sheet metal designs.
Repoussé and chasing are about stretching and folding metal into a design. Two other words used when describing this sort of work are sinking and raising, sinking is stretching the metal out like a balloon, raising is leaving the center of an area untouched and then pounding the edges in, "raising" them up (even though the process is usually done by "lowering" them below the level of the sheet) In blacksmithing terms sinking is like drawing out, it thins and stretches the metal; raising is like upsetting, it shrinks the surface area and thickens the metal. The terms sinking and raising are generally used to describe processes used in forming objects while repoussé and chasing usually have to do with the final detailing of those objects. Sinking and raising happens on very small local scales as you chase or repousage an object. It is sometimes useful to think about whether you need to stretch or compress the metal at a point to get some shape. All of these processes are about forming the metal bending it or squeezing it at one point so it moves relative to some other part. When one forms sheet metal or any metal for that matter, force is applied in one spot and the work is supported in another so that the metal is moved away from the force point relative to the support point. Sinking and raising are often done over air. The workpiece is supported at the edges or edge and driven down through the air relative to the support point. Repoussé and chasing differ from this in that the support is usually a very very thick fluid mix. Support is somewhat hydraulic, kind of like a waterbed. You push down in one spot and it pushes back some all around. From another per-spective, when you push down in one spot, the innate strength of the metal drags the adjoining areas with and the backing material pitch or other moves there too, a steel stake or die would not have moved. Clay gives the least support, pitch gives much more, lead or tin gives even more. Pitch is real useful because it can be stiff or soft as you need it by adding a little heat.
Clay will give you a loose amorphous edge, warm soft pitch a harder edge and cold hard pitch a much harder edge, lead or tin backing probably providing the tightest radii and edges.
All of this is useful, to every thing there is a season and a purpose, so says the old song. Initial work is best done over something soft like clay or beaten in over a wood block. You want those loose amorphous edges. You do not want to define something early on. If you make a couple tight lines, stress collects in corners, quite literally. It is like a pry bar in a crack. It doesn't seem like you are doing anything, but when you work an inch away on some easy curve, the gentle taps out there are multiplied many fold as they are transmitted to the area by the sharp bend. Eventually it will probably crack there. Now, maybe you wanted it to crack, but if you don't, be aware.
A couple of pitch tips:
I have been using the Red German pitch for several years now (ever since Allcraft started to import it from Europe) It is, as good as the Northwest pitch, doesn't smoke when heated and melts at a relatively low temperature. If you are careful not to overheat it, the pitch will last for years. Coat the back of your metal with mineral oil for easy removal. You can also use a regular chop stick (learned this from Anne Hollerback in Massachusetts). Always use a soft brushy flame, and be especially careful with the acetylene torch. A heat gun will work, as well.
piercing and cutting - punch, chisel, and saw
Applied design pieces are an excellent way of using that one little part of your last attempt that worked. Snag that tin out of the trash, cut out the good part and solder it on as part of a new composition. This can be especially fun, as you get to move an almost finished piece around and determine where it might look best.
finishing - paints, plate, and patinas
Beauty is only skin deep, . . . or so they say. Paints, colored bits of material in some sort of fluid medium which carries and as it dries binds the color in place. Plating, chemically depositing a metal on the surface. Patinas, corrosion and abrasion - chemical and physical colors and textures using the usually using the base metal and it's variously colored compounds, these colors are then usually fixed in place and color with a coating of some kind. Finishes usually have two major hurdles other than looking right, the first one is getting it to stick the second is getting it to last.
In all processes getting the surface clean is extremely important. Paints, enamels, solders all require a clean surface.
If you decide to re-tin the cover after annealing and forming, it needs to be cleaned with flux and the solder brushed on over the fluxed surface to get it to stick. For finishing there are chemical blackening and plating options as well. I used a copper plating solution called Copper Coat on the first one I tried. Patinas are often sealed with wax or laquer.
Sources for some materials and tools are listed at the end of this article.
I am sure 330 inventive, creative members are going to come up with some novel approaches.
I'm looking forward to seeing all your inventions and artistry at the conference.
Resources: Chasers pitch - Here in Minnesota, Corky Kittleson and I (Gene Olson) have several lbs on hand from Northwest Pitchworks. With freight the cost from Bellingham is about $9.25/lb. If you want a few oz. to try give Corky or I a call.
300 East 4th St E Apt 201
St Paul, MN 55101-1441
Home phone: 651-848-0759
Work phone: 651-773-4662
8600 O'Dean Ave NE
Elk River, MN 55330-7167
Home phone: 763-441-1563
Fax number: 763-441-5846
If you want pounds of it, you can get it from these places.
1317 Roland Street
Bellingham WA 98226
|Red German Pitch from
Allcraft NY NY
Tel: 212-279 7077; 1-800-645 7124
Copper Plating solution for Tin, iron, lead, brass called COPPER COAT
888 Brannan St.
San Francisco, CA 94103
|Note: this is simply a mixture of copper sulphate
(sometimes used as an herbicide to kill aquatic plants)
and sulphuric acid (acid drain cleaner).
Acid Handling Safety rules apply. Wear goggles & gloves, add acid to water not the other way around.
Tools such as the jewelers saw: Rio Grande 1 800 545-6566
Our own Fiorini and Skiles make repoussé tools 507-643-7946
You can make your own, or convince your favorite smith to help.
Good luck to all!
Back to this issue's index - Back to Metalsmith index - Back to Educational article index