Refrain Process

The information and images below depict some of the processes Gabriel Akagawa goes through to make Refrain iron railroad tracks. The lost-wax casting process is employed.

Hydrocal plaster molds are made from waterproof sealed toy wooden train track patterns.
Casting Remet microcrystalline wax into the plaster molds (plaster molds are soaked in warm water as a mold release for wax casting).
Cast wax tracks left and sprue systems right. Each track is stamped with text and wax-welded onto the sprue system (the passageways by which the metal gets into the the pattern). The positive forms in wax will eventually be melted out of investment molds. The negative space where the wax pattern and sprue system was will be replaced by metal.
Photo detail of individually stamping letters. Each side of each track has one word embossed into it. Each wax track has to have extra wax removed; the pour spout and parting line flashing that is produced when casting into the plaster molds.
Straight and curved tracks with text stamped into the wax. The pictured curved track above commemorates an iron pour where some Refrain iron tracks were cast.
Gabe’s standard configuration has eight tracks per “tree” (term used for multiple patterns per mold). Eight allows enough space for ceramic shell slurry to be brushed into the text and (after being cast in metal) the patterns cut from the sprue system.
To the left are the finished waxes with attached vents (passageways by which the air escapes the patterns from the liquid metal displacement during metal casting). The right tree has the first coat of investment (Remet ceramic shell).
Final ceramic shell liquid colloidal silica “slurry” coat.
Ceramic shells before wax is “burned-out” and vitrified.
After a “burnout”, the de-waxed and vitrified shells or molds.

Frequently asked question: ‘Why only cast eight tracks on a tree?’

Answer: The weight and scale of the ceramic shell molds (6.5 pounds) and metal castings (15 pounds iron) allow for easier handling and transportation. Akagawa often has time/family restrictions to attend one day of an iron pour. Smaller trees allow for easier pre-heating of molds, easier setup and cleanup, faster cooling of the metal, and less emotional impact if a mold fails.

Images above and below: Two molds filled with molten iron at (Fe)Male Iron Pour in Peoria, Illinois November 2, 2019.
Above: November 9, 2019 at University of Wisconsin-Whitewater
Several molds were cast October 26, 2019 at 555 Non Profit Gallery +Studio in Detroit, Michigan.
Ceramic shell is mostly removed by chipping with mild steel “spike” and a ball peen hammer before sandblasting.
Sandblasting to remove last of ceramic shell mold material.
Pneumatic die grinder is used to do final shaping of the iron, ensuring all pieces fit together in any combination.
Each track is cut from its sprue system, checked for fit and sand blasted before patination.
Patina applied. Extra “rust” removed with scouring pad and water.
Tracks heated to remove moisture and to prep for final wax. (Ari Akagawa)
Wax applied to warm/hot iron ensures wax permeates surface.
First 57. Each cast iron Refrain track weighs 0.8 pounds.
Ari testing fit-up on a shelf.

Return to the Refrain project description