== Basics of Moving Metal ==
What do we know about metal?
- Metal consists of imperfect crystalline structures. When any work is done to the metal it compresses these structures moving them closer together, creating stiffness in the metal or work hardening. This work hardening is important to understand when moving or forming metal. If the structures become too compressed fracturing will occur, causing splits or fissures in the metal. Over working a metal can cause brittleness and threaten the structural integrity of the piece.
- To avoid overworking it is important to understand the properties of a work hardened piece and the properties of a dead soft piece. Dead soft is another term for annealed. To Anneal a piece means to heat the piece to a certain temperature evenly. This temperature varies between metals; silver, copper, brass and bronze all exhibit different reactions at specific temperatures.
**A work hardened piece will be rather difficult to move, bend or form in any way. It will also sound different. Hardened metal has a higher tone to it when struck or tapped. Work hardened metal can damage tools. The only time a work hardened piece is a good piece is when it is finished. Hardened metal takes a better shine/polish then annealed metal. **A dead soft or annealed piece will move rather easily, especially copper. Annealed metal has a dull tone to it when struck or tapped.
Best practices when moving metal
- Different forming techniques usually employ particular ways of moving metal, such as fold forming or raising.
**Fold forming is the art of folding metal to create dynamic 3D forms. **Raising is the art of forming a vessel from a flat sheet of metal.
- A good rule of thumb is to move the metal from inside to out if you are stretching the metal, for instance when doming a disc or raising a vessel. This spreads the metal evening keeping the thickness even throughout the entire piece. Thickness affects the annealing process as well as processes such as enameling or powder coating. Variances can cause failure in the process.
- When compressing metal be sure to avoid overlapping, in the case of forging it is important to true the strikes on the metal. Fins created in this process should be filed away before continuing. If they are folded in while forging it could cause cracking and instability in the piece.
- Anneal often during any forming process.
- Use the right tool for the job.
**Forging **Raising **Fold Forming **Fabrication **Roller Printing **Resizing/Regauging **High Pressure forming
Tools used in moving metal
**Hammers of all sorts **Disc cutters **Dapping punches and block **Sinking dishes, tree stump **Raising stakes **Bench vise **Torches **Files **Anvil **Rolling Mill **Pliers **Mandrels and dies **Hydraulic Press
Die Forming is a technique that utilizes pressure or force on metal suspended in a hollow form. To be clear an outline of a shape is made and cut out of a material (wood or metal or delrin) on two pieces, the metal is sandwiched between the two cutouts and force is applied causing the metal to form one way into the cutout.
Manual Die Forming
Manual die forming can be an alternative method of achieving the looks of a piece formed with a hydraulic press for larger pieces. The method is similar with minor alterations. For example, instead of the hydraulic press creating the force or pressure to push the metal into the form, it is done with a forming hammer in multiple passes. After each pass the piece must be removed from the form and annealed to continue to sink the metal into the form.
What can this method be used for?
*Vessels *home decor *helmets *bowls *sculpture
Materials needed to use this technique:
- MDF board or Delrin sheets at least 3/4" thick
- Bolts with nuts and washers to span half the width desired
- Saw or shopbot to cut material
- Two sheets of equal sized metal
- Hammers--(Delrin and forming, possibly embossing)
- Drill and bits to match bolt size (if using shopbot be sure to include your holes and for the bolts in your design, you may want to counter sink on the bottom of the design.)
- Cleaning supplies (to clean metal)
- Solder (if creating two halves of a whole)
The steps to creating a piece this way are as follows:
1. Design your piece (fully rendered sketches) 2. Trace only the profile of the piece you are creating (this will be half of the fully formed piece) See pictures below 3. Use your tracing to create a die in which the metal will be formed into. This is done by tracing the outline of the profile onto a piece of delrin, or MDF, depending on the depth of the desired piece you may need to cut multiples and stack them. 4. Cut out your design on all sheets needed. It is recommended to use the shop bot for this step to ensure repeated accuracy. 5. Drill holes for bolts. Holes must be matched on all frame pieces and the metal. 6. Be sure to fully anneal your metal before placing into the die. 7. Begin slowly pushing the metal down into the form from the edges down, this is done with a delrin or forming hammer starting at the edge of the die, moving around the edges and out eventually to the middle. This method will stretch the metal in an even manner.Be sure to be even with your force. 8. At the completion of each pass remove the metal from the frame and anneal. 9. If making two halves of a whole, work each side before moving forward. Remember to reverse the die to do left and right sided pieces. 10. Continue pushing each half until the desired depth is reached. 11. Check occasionally, the equality of the halves together, adjust accordingly. 12. When the desired depth is reached, remove the sheets from the form and cut out the design. 13. Filing and sanding edges to match sides together, then solder. 14. Depending upon the size of the piece it may be necessary to build a kiln like structure to maintain heat while soldering.
Hydraulic press forming is magical. Using this method it is possible to form small pillow forms in a myriad of shapes. The press causes pressure to build up, pushing the metal into the form or die. Dies for the hydraulic press should be made of steel, but could potentially (limited life span) be made from delrin or heavy duty acrylic. When using a hydraulic press to form, the amount of rubber or silicon used can affect the depth achieved. Using the hydraulic press method allows the user to make much smaller/ intricate shape designs that could be possible with manual forming.
What can this method be used for?
*pillow or hollow form jewelry pieces *small vessels *small dimensional pieces to add to larger pieces *ornaments *home decor
Materials needed for this method:
- metal of choice
- dies (steel, delrin or heavy acrylic)
- hydraulic press
- rubber or silicon mats of varying thicknesses
- equipment for annealing or soldering
- Jewelers saw and other bench tools for finishing.
There are manual hydraulic presses and electric hydraulic presses. A 20 ton press should be sufficient for most forming needs on this scale. Blowouts can happen when the pressure reaches a specific point. This is usually just above 2200. A blowout is when the metal cuts at the edge of the die and is "sucked" into the die. Ideally, this should not happen. It is recommended to increase the pressure slowly if manually working the press, electric presses have a set increment of pressure.
Below are a few resources, more to come as they become available.
- by John Fetvedt [Web link]