The Art of Embossing Metal
Repousse is an ancient and honorable art form, dating back almost as far as men have worked metal. Repousse, simply put, is raising a design in relief on metal from the back or inside using hammers and punches. Details are then generally done on the design from the front, using chasing or engraving. The whole technique is sometimes referred to as ‘chasing’, or embossing. Three examples of repousse, not dating all the way back to the dawn of metal working, but none the less quite ancient, would be a Chinese sleeve weight in the Freer Gallery of Art in Washington D.C., dated to the Chou Dynasty (c. 1111 – 255 BC), the Gundestrup cauldron in the Nationalmuseet, Copenhagen, found in a Danish peat bog in 1891, dated and placed as originating in eastern Europe around the second century BC, and thousands of golden ‘spangles’ found in Tillya Tepe in Afghanistan in 1978, placed as local Kushan work dated to around 100AD. These last were in Kabul in 1982, but due to the Afghan Civil War, our best documentation might be the article "The Golden Hoard of Bactria", by Victor Ivanovich Sarianidi in the March 1990 issue of National Geographic.
This exposition is to teach the basic techniques necessary to do repousse, and get students well on their way to making objects that are not only beautiful, but useful as well. For this, I have given designs for several panels. These will be ‘practice’ pieces. Then, I have given instructions on how to take these panels and make a small brass box. There is nothing that says students cannot come up with their own designs, nor that they cannot make other items, either useful, or simply decorative. In fact, I strongly encourage my students to so do. However, before beginning to work on the panels themselves, students need to have a few basic tools. Here we run into a slight problem. It is not possible to run down to the local tool or hardware store and buy most of the needed tools. I am sure there are a few sources somewhere, but I have never found one. Therefore, since we can’t simply buy the needed tools, we will have to either make them, or have them made for us. Fortunately, the tools are generally inexpensive, and quite easy to make, if you have access to a few common tools and pieces of equipment.
For working in soft metals, such as gold, silver, copper, or brass, the hammers used must be lightweight. I made a light wooden mallet using a model wooden pickle barrel bought at a craft store, but any good hard wooden piece about three-quarters of an inch around, and about one and one-half inches long can be used. Drill a seven-sixteenth inch diameter hole through the piece, from side to side. Then, take a piece of seven-sixteenth-diameter dowel about ten inches long. Using sandpaper, turn one end of the dowel down till it fits the hole. Stop frequently, and check the fit. You want the dowel to slide in snugly, but not so snug that you can’t slid it back out. Then firmly glue the dowel into the hole you previously drilled. It will help if you groove the turned down section slightly for most of its length. Use carpenter’s wood glue, which is something like Elmer’s white glue. Don’t, however, use Elmer’s white glue. It is too soft, and is not waterproof. If you like, you can round the other end of the handle for comfort. When this mallet is completed, it will be your light mallet. Then, you will make a heavy mallet. Use a section of closet rod about three inches long, and a five-eighths inch dowel about twelve inches long. Drill a five-eighths inch diameter hole in the closet rod. One caution! Keep the grain running from side to side of the head, not up and down parallel to the handle. It is much stronger that way. This is true for both mallets. The dry fit should be as before, and the grooves will also help in getting a good glue joint. These should be the only mallets you need for soft metals. If you are going to be working in steel, you will use metal hammers of a heavier weight. A sixteen oz. ballpein and a twenty-four oz. ballpein should do quite nicely.
Next, you will need punches. For soft metals, I recommend using tempered concrete nails to make five of the needed punches. Buy the largest and longest you can find. Another good source of stock material is long hex wrenches or what are commonly called ‘Allen’ wrenches. These will have to have the short leg cut off, so that the punch is straight. This can be done with a hacksaw.
To shape the nails, or the hex wrenches, they will first have to be annealed. Using a propane torch, heat the points of three nails until they are bright red. Then allow the points to slowly cool. When they are cool, grind one to a point about like what you have on a fine point ballpoint pen. This we will call the ‘sharp’ point punch. Grind the second one to a point about like what you have on a very dull pencil. This we will call the ‘round’ point punch. The third one should be ground to a very round contour, like a ball. This we will call the ‘ball’ point punch. Heat the points of two nails until they are bright red. While still red hot, hammer them flat into chisel shapes. Reheat until bright red again, and allow to cool. When they are cool, grind one of them along the long edge into a profile similar to the sharp point punch, and round the corners. This we will call the ‘sharp’ chisel punch. Grind the other one along the long edge into a profile similar to the round point punch, and round the corners. This we will call the ‘round’ chisel punch. Using 600 grit wet or dry sandpaper, wet sand all the points lightly to remove any burrs, and if you have a polishing wheel, polish the ends to a mirror finish using jeweler’s rouge. Now they have to be re-tempered. To do this, heat them to a bright red again, and instantly drop them into a container of (used) motor oil. When they are again cool, re-polish the ends, and they are ready to use.
You might eventually need some punches that are larger in diameter than concrete nails will produce, especially if you have relatively large surfaces to raise. These can be made from commercially available punches or chisels. If you are working in steel instead of soft metal, all the punches will have to be made this way, as concrete nails will simply be too small to grip properly. Make the first three punches described above from three-eighths inch diameter center punches, and the last two from quarter-inch chisels. You will have to anneal and re-temper these the same as with the nails.
For the large punches, to use on steel, use five-eighths inch diameter punches. After annealing, grind the point of one into a ‘flat’ about one-half inch in diameter. It should not be absolutely flat, but should have a very slight convex profile. Round the corners. After polishing and re-tempering we will call this the ‘flat’ punch. Grind the other punch point into a ‘flat’ square shape. This one should actually be flat, and about one-half inch across. Round all the corners. This will be called the ‘square’ punch. For soft metal, make these punches about one-quarter inch diameter or square, using three-eighths inch diameter punches. Two more punches needed will be made from five-eighths inch chisels for steel, or three-eighths inch chisels for soft metal. Round the corners and grind the edge on one chisel to about the diameter of the ball punch. We will call this the ‘ball’ chisel punch. Round the corners and grind the edge on the other one to about twice the diameter of the first one. We will call this one the ‘oval’ chisel punch.
That should be all the punches needed. At least to start. Using the above techniques, you can make specialty punches as required to do specific jobs as you get better and more elaborate in your designs. Now you need a surface to hammer on. If you can get a twelve inch diameter piece of hardwood about six inches long, wonderful. It should be a close grained wood, so don’t use oak or ash. Pecan or hickory will do. If you cannot get hardwood, you can use a soft wood such as pine. If you do have to use pine the finished product may not be quite as ‘crisp’ as if you used hardwood. Sand the end of the block as smooth and as flat as possible. Two additional tools will be a very good pair of offset metal snips and an Exact-o knife. That’s it for tools, at least for the actual embossing. It took me almost as long to describe them as it should for you to make them.
Here is a design you can copy as a practice piece. Leave about one inch all around the outside, and do two of them.
They should be done
full size. Well, go ahead!
Now, starting at the center, either top or bottom, cut away the flower like designs. Work towards the corners. Then cut out the acorns. Last, starting away from the corners, cut out the corner pieces, and then cut the border in. If you have done it right, you now have the complete pattern scribed on the sheet. This is the back side of the sheet, remember. Remove the remains of the pattern. If you have missed a few spots in scribing, go back now and scribe them in freehand.
You are now ready to start pounding. Place the piece on the wood block, pattern side up. We are going to do the four V shapes first. Using the sharp point punch and the light mallet, start at the point of the V. Angle the punch about ten degrees away from the V, and lightly tap the punch. Work the point along the line of one leg of the V, tapping as you go. See why it is sometimes called ‘chasing’. Go back to the point of the V and do the other leg. We are only trying to raise the face about one-sixteenth of an inch. If you didn’t raise it that much, go back and do it again. Eventually, you will develop a ‘touch’ for how hard to hit the punch. Right now, it is more important not to hit too hard. Now do the other three V’s the same way. Are you beginning to feel comfortable with what you are doing? Good!
Now we will move over to a large design. Let’s do the leaf things at the ends of the panel next. Still using the same tools, start at the point of the ‘bottom’ leaf, and chase the outside line of the leaf to the stem. Then do the inside line of that leaf, from the point to the stem. Then move up to the big leaf, and do it as well. Remember to start at the point and work to the stem, outside line, then inside line. Work the next two leaves the same way, in order. Then start on the leaves on the other side of the stem. When you finish that, change to the round point punch. Start at the point of the bottom leaf, and raise the center section part the way down towards the stem. When you can change to the ball point punch, do so, and raise the rest of the leaf. Do the rest of the leaves the same way. Now, outline the tassel at the top, and raise it. Now do the stem. Change tools as required to get the proper width line. When you finish one end, start on the second leaf design.
The acorns and flowers can be outlined with the sharp point punch, and raised with the ball point punch. The stems for them can be done with the sharp point punch and the round point punch. The corner designs will require all three punches. The small diamonds at the V’s can be done with just the sharp point punch. They can be just outlined, leaving the center unraised. The crescents will require all three punches. Now for the center section. Outline and then raise the four thorn-like things on the outer circle. Then, using just the ball point punch, chase the outer circle. Then outline and raise the center leaf, and the three leaf-like projections on the center circle. Finally, using the ball point punch, chase the inner circle, and the border.
Now it is time to detail the piece. Turn it over. Detailing will require a little bit of freehand work. Using the corner of the sharp chisel punch, you should chase around every raised area, outlining them as you tap the punch. What you are trying to do is force the background areas back down flat. In areas where you cannot use the sharp chisel punch, use the sharp point punch. These would include any small inside curve, or other really small area.
Here is another pattern. As you can see, it is quite similar to the first pattern.
Cut the lines that cross the star first. Then cut the star out. Then follow the directions given above for scribing the rest of the pattern. For chasing everything but the star, also follow the instructions given above. Complete the detailing on the rest of the piece before starting on the star. To do the star, follow the instructions below.
Working on the back side, outline the star using the sharp chisel punch. Start where two pointed areas intersect and work to the points. When the entire star is outlined, start at the large points using the sharp chisel punch, and chase the lines towards the center of the star. Stop just before you reach the center, and finish by working from the center back to where you left off. As you work towards the center of the star, increase the weight of the taps you are using, and make the ones from the center out especially hard. Using the same punch, now chase the lines from the small point to the center. Increase the weight of these taps as you work towards the center, also. These can be chased all the way to the intersection at the center. Now turn the piece over face side up. Detail the outline of the star using the sharp chisel punch. Start at the points and work inward. To finish the star, you will now use the same punch, and starting at the center, you will chase the lines dividing the points from each other. This is still on the face side.
This piece, when completed, will be the top of your box. The first two pieces will become the back and front of the box. Now you need to make two end panels. Here is a design you can use. Remember to leave a one inch margin all around.
This is also similar to the first two panels. With what you have already done, you should be able to figure out which tools to use, and how to do the four new motifs on this panel. Remember that you will need two of these panels, and they must be one inch larger than the actual pattern. When these two pieces are finished, we can begin to put these five embossed panels to use. We will do that by constructing a small brass box.
I realize that box construction has absolutely nothing to do with the art of embossing metal. I include it only to show what can be done with embossed panels. For making the box you will need some additional tools. Luckily, they can be bought, and they are not very expensive. The first tool you will need is a pair of vise-grip type sheet metal pliers. The ones made in China will do okay, but if you absolutely insist on buying "Vise-Grip" brand, that's fine with me. They are better, but they are about three times the cost. You will only need two pair. Select one of the previously embossed front/back panels. Using the metal snips, cut a notch in each corner as per the diagram below.
The notch should
be cut in three-quarters of an inch from the outside edge, with the
inside corner slightly rounded. Then use some fine (220 grit)
sandpaper and smooth the cut edges. When using the sandpaper, be sure
not to drag it or rub it on the face or lip surfaces. Clamp the sheet
metal pliers on one end, aligning the outer edge of the plier jaws with
the notches. Carefully, holding the pliers in your hands, and using
both thumbs on the surface of the piece, bend a lip down away from the
face of the piece. If it is necessary, you may move the pliers back
and forth along the piece so that they are located where you are bending.
When you have bent
this lip approximately 90 degrees, use the light wooden mallet, and
tap along the face at the very edge to make this a sharp bend. When
finished, you want this lip to be at 90 degrees from the face of the
piece with a sharp-edged bend. Once again, move the pliers as necessary
so that you have the jaws to hammer against.
Do the other end the same way, and then trim the lip until it is only one-eighth of an inch wide. Round the corners and smooth the cut edges with the sandpaper. Do the other front/back piece the same way. Make sure you don't do the top piece by mistake. Remember that it is the one with the star motif. The next step is to cut the notch at the bottom edge of the piece at a forty-five degree angle.
Then bend a lip as you did on the ends. Bend down away from the face. You will definitely have to move the pliers up and down the piece for the long edges. Start at one end, and bend it about one-fourth of the way to where you want it. Then move the pliers, and bend the next section. Keep doing this until you reach the end of the piece. Then go back and repeat this process, bending it only about one-fourth of the way each time, until it is bent to approximately the desired 90 degree angle. Then, use the mallet as you did before, and sharpen the bend. You will need to move the pliers along the bend as you do this, so that you are always tapping right on the jaws. When this edge is sharply bent to 90 degrees, trim this lip so that it is one-quarter of an inch wide. Do both the front and back pieces this way. Round the corners, and smooth the cut edges with the sandpaper.
Now you will work on the two end pieces. Notch the corners as you did on the front and back pieces. The sides of these pieces will be done exactly the same as the ends of the front and back pieces, except that when you trim them, trim them to one-quarter inch wide instead of one-eighth inch. The bottom edges will be done exactly the same as the bottom edges of the front and back, with no exceptions.
So far, we have only been doing simple bends. The rest of the bends are a little more complicated. On the top edge of the four panels we have already worked on, the bends and trimming information will be identical, so I will only describe it once. Just remember that this is only for the top edge of the four panels that make up the sides of the box. Trim one-fourth of an inch off the edge of each panel. Then, bend down away from the face a one-eighth inch lip. This lip must be bent more than 90 degrees. You will want to bend it as much as is possible. When the jaws of the pliers prevent it from being bent any more, then use the light mallet to sharpen the bend. You will have to move the pliers along the piece as required during both the bending and sharpening processes, as you did on the simple bends. Then place the piece face down along the very edge of your wooden block, being sure that all the embossing work you have done is off the edge of the block Then using the heavy mallet, tap this lip down until it is flat against the rest of the tab.
The next step is to trim the corners of this folded part on a 45-degree angle. It is important not to cut deeper than the folded part. After cutting, smooth the cut edges with sandpaper as you did before. Do not round the corners on these cuts, however.
Now you have to grip this flattened edge with the pliers, and slightly bend it back toward the face. You should not bend it more than about 15 degrees.
Now move the pliers to line up with the notches, as normal, and bend a lip down away from the face. This lip will be bent more than 90 degrees, just like the eighth inch lip.
Now, grip the eighth inch lip with the pliers, and use the heavy mallet to tap this new quarter inch lip flat, while bending the eighth inch lip up as shown below.
Now we are ready to finish out the top of the box. This will require a little bit different cutting pattern than we used on the sides. Also, because of the complexity of the cuts, you will have to make some of the cuts with a jeweler's saw instead of the snips. "X-acto" makes one that is available from most of the same places that you can buy "X-acto" brand knifes. You can use a relatively course blade, which will be thicker, and therefore somewhat harder to break than some of the blades used for intricate details on jewelry.
When placing the blade in the saw, first loosen all wing nuts. Make sure that you have about three-sixteenths of an inch of exposed thread at the wing nut opposite the handle end. Next, place blade in block by the handle, and tighten that wing nut. The teeth must be set so they face back toward the handle. You want them to cut on the pull stroke. Then place the blade in the block at the opposite end and tighten that wing nut. Now, push the movable bar at the top until the blade is as tight as you can get it by hand, and tighten the top wing nut. The final step is to tighten the last wing nut, thereby placing the blade under considerable tension. You might have to use a wrench on the block to keep it from turning. If the block turns, the blade gets twisted and it will break. To saw with a jeweler's saw, especially on thin material like we are using, the work piece must be firmly supported. With 26-gauge brass I doubt if you will need a back-up for the work piece, but you will have to saw very close to the edge of your work bench, and use clamps to hold the piece to the bench. The handle will go down below the work, and you will cut on the down stroke. Don't rush the cutting process. Not only will going slow give you better control, the blades are fragile, and you will break blades by rushing. The blades are not expensive, but it is such a hassle changing them. Make sure to keep the saw straight up and down as you cut.
The four corners of the top should be cut as shown below.
Make all the corners sharp when you cut them. Obviously, you can use the snips to cut the three-eighths wide strip off the edge, but the rest is all saw work. After all the corners are cut, use the sandpaper and smooth the cut edges. You may slightly round the corners of the little eighth inch square tabs if you want to, but it is not absolutely necessary.
On the ends of the piece, align the plier jaws with the eighth inch tabs, so that you are bending a small lip. Bend this lip up toward the face to a 15 degree angle. Then align the plier jaws along the 'bend line' shown, and bend this lip down as much as you can. Sharpen, and then grip the eighth inch lip, and using the mallet, tap the wide lip flat as you bend the eighth inch lip to a 90 degree angle. This is similar to what you did on the top of the four side pieces, so I won't show this operation. Now bend the eighth inch square tabs in toward the center of the piece to a 90 degree angle, and sharpen.
Bend the eighth inch square tabs on the side pieces down away from the face, and sharpen. Then bend the long eighth inch lip up toward the face to a 15 degree angle, and bend the wide lip along the bend line as much as you can. Sharpen, and then grip the small lip and tap the wide lip flat while bending the eighth inch lip to a 90 degree angle. If you have done everything right, the corners of the top should be quite sharply pointed. Use the sandpaper, and round them quite a bit.
Pry the eighth inch square taps away from the lips where they overlap, and place a small piece of fine rosin core solder in each side of the joint. Then, using small paper clamps, clamp the tabs back down tight against the lip. Heat with a propane torch until the solder melts. Leave the clamps in place until the piece has cooled. The top is now complete. You can either leave the top loose, or make hinges and hinge the top to the box. I will show you how to make hinges just in case your decision is to hinge the top.
You will need one piece of three-thirty seconds inch diameter brass rod, and one piece of the three-eighths inch wide strips you cut off the top. Then using the jewelers saw, cut four pieces off of one end of the strip as shown below.
It will require two of these pieces to make one hinge. Take one of the pieces with the single tab sticking out, and using a pair of smooth -jawed duck-bill pliers, bend the tab around the three thirty-seconds inch diameter rod. Remove the rod, and carefully solder the end of the tab to the body of the hinge, being careful not to get solder in the loop where the rod goes. Take one of the pieces with the two tabs sticking out, and bend the tabs around the rod as you did with the single tab. Remove the rod, and solder these tabs as you did with the single tab. Then do the other two hinge pieces the same way. Cut two pieces three-eighths of an inch long off the end of the three thirty-seconds inch diameter rod, and smooth both ends of the rods with the sandpaper. Also smooth the cut edges of the hinge pieces.
Now put the hinge together and solder the rod into one end of one loop. Make sure to put the pieces together as shown below, and that the hinge flexes easily.
After the hinges are both complete, it is time to dry fit them to the back panel and top panel. They may have to be trimmed slightly so they will not overlap the embossing on the back panel, or interfere with the lip on the underside of the top panel.
When you are sure the hinges fit properly, solder them to the back and top as shown, and the box is ready for final assembly. Dry fit the end panels inside the back panel, and measure the inside dimensions of the box. Cut a piece of sheet slightly smaller than the inside dimensions of the box, and dry fit it into the box. Now dry fit the front panel to the box. It also goes outside the end pieces. Now disassemble the box, and solder one end panel to the back. Then solder the other end panel to the back. A good way to solder these is to cut some small pieces of solder, and clamp the two pieces into position with the solder pieces between the surfaces to be joined, using small paper clamps. Then heat carefully with a propane torch just until the solder melts. Place the bottom piece into the partially completed box, fit the front to the box, and solder the front in place. Turn the box upside down, and support the bottom on a couple of blocks, letting the box sides hang free. Insert small pieces of solder between the side lips and the bottom, and carefully heat. It might help to clamp the box together while you are soldering the bottom in. Soft copper wire wrapped around the box, and twisted tightly should hold it together. With the soldering of the bottom in place, the box is finished. If you desire, you can polish the box using a buffing wheel and jeweler's rouge, but it is not required. Only the outside needs to be polished. You can line the inside with velvet if you like, or leave it plain. If you are going to line the box, cut the lining and glue it in with contact cement after the polishing is completed, as the rouge will get all over the lining if you don't. At a later date, I will add to this work with several more projects, both useful, as this project was, and purely decorative in nature, but for the present, this should get you started on learning to do Repousse.
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