DIY Network

Welding and Metal Chasing Bronzing is applied to the wax figure. From "Trade School" episode DTRS-310

In this segment, foundry apprentice Jeff Herndon makes preparations to weld the bronze pieces together and restore the original appearance of the sculpture.

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Safety Note: Always wear proper gear, including mask, gloves and smock when using welding equipment.

1. After the bronze has cooled, Jeff carefully breaks off and discards the ceramic shell of each piece using a hammer and wire-cutters (figure A). He makes sure to only strike the ceramic so as not to damage the underlying bronze.

2. With no more use for the now bronze sprue bars, Jeff uses a plasma cutter to cut them off (figure B). These eventually make their way back to the pour floor for reuse.

Figure A

Figure B

3. Jeff uses a sandblaster to remove any hard-to-reach ceramic remnants remaining in highly detailed areas (figure C).

4. With the bronze cleaned entirely of the ceramic, Jeff prepares to weld the pieces together by first burning off any remnants of the sprue bars with a TIG welder—cranked up to a very hot setting (figure D).

Figure C

Figure D

5. He then uses a bench grinder to clean up the edges on each piece (figure E).

6. With the edges cleaned up, Jeff can now weld the pieces together. After properly lining up two pieces, he uses the TIG welder to tack the pieces in place. For his first pass along the seam, he uses the welder to fuse the pieces together. For his second pass with the welder, he melts a rod of metal to fill the seam (figure F).

7. Before welding the bust piece to the body, Jeff finds several spots along the edge of the body that have warped inwardly. To correct the problem, he first aligns and tack-welds the pieces together. He then positions a special hydraulic jack, called a ram, inside the piece and forces the areas out and into alignment (figure G). As the ram applies pressure, Jeff welds across the aligned seam. He continues welding until all the pieces area back together.

Figure E

Figure F

Figure G

8. Jeff concludes by using a variety of grinding tools to remove imperfections, and then restores the sculpture's original look in a process called metal chasing.

Safety Note: Always wear a protective face shield when using grinding equipment.

9. Jeff starts this process by removing the bulk of the weld seam lines using an angle grinder (figure H). While grinding, he makes sure not to remove too much metal.

10. To recreate a grainy texture, such as hair, Jeff uses a smaller disc grinder with a sanding cone attachment to rough in the lines over the weld seams (figure I).

Figure H

Figure I

11. Jeff uses a wire wheel attachment to blend and smooth the freshly ground metal areas (figure J).

12. To "draw" in sharp crevices and details, Jeff utilizes a pencil point grinder (figure K). He softens and blends these details with the wire wheel attachment.

Figure J

Figure K

13. To restore large surface areas, Jeff uses a large seven inch angle grinder (figure L). This grinder sands out any scratches along the weld seam and quickly provides a smooth contour.

Inspected for quality and workmanship, Jeff's first complete bronze production passes with flying colors (figure M). Note: To add actual color, an offsite specialist applies a patina finish to the completed piece.

Figure M

Figure L

Now ready for display, "Corn Girl" awaits her new home.

RESOURCES :

Art Castings of Colorado
Website: www.artcastings.com