Lesson: Dapping and Synclastic forming

Perfecting Basic Skills

Winter 2018 Baltimore Jewelry Center

Jenn Parnell, Instructor

Lesson 1:  Dapping and Synclastic Forming

• Synclastic forming is the classic bowl shape and variations of that. If you divide your flat shape into quadrants, for synclastic forms, all quadrants are bending in the same direction- i.e. the bowl shape. Anticlastic is when 2 quadrants ebnd one way, and 2 the other- i.e. saddle shape.
• Dapping blocks and punches are easy and quick ways to create synclastic forms. You do not need to use only round discs! Explore how different shapes look!
• In order to give your sheet metal three-dimensional form, you can use the dapping block and punches, stakes, sandbags, wood blocks, or stumps. Over the course of this class you will become familiar with all of these!
• When forming metal- ALWAYS ANNEAL FIRST! You don’t need to pickle after annealing unless you use flux.
• You will feel the metal get harder to form after hammering it- this is called work hardening. Anneal when this happens to soften the metal.
• Metal stake + metal sheet + rawhide/plastic mallet = no marks, less exact fit, no thinning of the sheet
• Metal stake + metal sheet + metal hammer = marks, perfect fit to stake, some thinning of the metal.
• When using a metal hammer, make sure to hit evenly across your piece.
• Metal hammers will harden the metal faster, you must anneal more often.
• NEVER put anything wet on a metal surface!!!! Dry your piece thoroughly before coming to the forming room.
• Do not hit a metal hammer directly onto a metal stake or block.
• Wear ear protection!
• Blue handles= only touch your piece
• Hammer= metal face   Mallet= plastic, wood, or rawhide face; green handles

Using the dapping block and punches:

• When starting out, your disc should be approx. ⅓ - ½ of the way down in the depression.
• Use the largest punch that fits in the hole that also leaves room for the metal!!  
• Hammer the punch with a mallet or orange handled hammer.
• Go in size order for the holes- they may not be on the same side of the block!
• Don’t move on to the next hole until you hear the solid sound and the outside of your disc is shiny. This means you are all the way at the bottom of the depression.
• Anneal your disc every 3 holes.
• Because the metal will be deformed and compressed along the edge, you will need to file the bottom of your hemisphere prior to any soldering or measuring.
• Measure both diameter and height to determine when you have reached you desired shape.
• Because the punches stretch the metal in the center and compress the metal closer to the rim, do any piercing or drilling after forming.
• If you want to drill other than in the direct center of the form, use the flexshaft.

Using the Stakes:

In order to form the metal, you want to hammer it down to the surface of the stake. Therefore, you want to hit the point of the metal that is just off of the stake. Start on the edges of your piece and work toward the center. When you have reached the center, go to the other edge, and begin again. You want to hammer on one area of the stake. Rotate and adjust how you are holding your piece so that this is possible.

To make your forms look more regular and true to the stake, after forming with a mallet, use a planishing hammer or goldsmith’s hammer and go over the entire surface of your form. If you do not want the hammered look, file and sand to achieve a smooth surface.

Cutting round discs:

We have several disc cutters that make getting a perfect circle easy! However these only come in certain sizes.

To use:

• Place your non-annealed sheet of metal in between the top and bottom plates of the cutter. For some cutters this is a slot, other cutters pull apart, yet others have a screw that holds the top and bottom together.
• Tighten top and bottom down if applicable.
• Find the cutting punch that fits *tightly* into the hole. Make sure you are looking at the cutting end (sharp edges) and not the hitting end (rounded off or beveled edges, also usually not polished)
• Place punch in the hole with the cutting side touching your metal.
• Use a big heavy mallet and strike the punch.
• The less times you have to hit the punch, the cleaner the cut. Hit hard!
• Pick up the disc cutter so the punch falls through along with your disc.
• Loosen the top and bottom and remove your sheet.

If the disc cutter doesn’t have the correct size, cut out your circle.

• Use a center punch to mark the center of your disc.
• Take a pair of dividers and set them to the radius of the circle (radius= ½ diameter)
• Place one tip of the dividers on the center punch mark, the other against your metal and spin the dividers to leave a clean mark on the surface.
• When cutting, cut just outside the line.
• File down to the line for a perfect circle.

Assignment: Sample Bead

• Using the disc cutter, punch out 2 circles. Use the largest disc punch.
• Use either 22 or 20ga. metal.  
• Anneal with torch.
• Form circles into hemispheres. The diameter should measure 2x the height for each hemisphere.
• File and sand the edges.
• Drill a hole in each hemisphere.
• Solder together to make a spherical bead.
• File and sand and finish.
• Feel free to add pierce work, solder cutouts onto it, patina it, etc.