Materials used in "Art Giants in Detroit" artworks.
The "Art Giants in Detroit" artworks employ modern materials. The substrate of these works is a four feet square slab of two inch thick extruded styrene. urethane foam is applied to the face and sides of the slab to create a lumpy surface and allowed to cure. Because the surface of urethane foam is susceptible to degradation from long term exposure to ultra-violet light (see below), the entire object is then coated with several layers of titanium dioxide and zinc oxide suspended in laminating non-blush epoxy. This concludes the initial preparation. The portrait is hand painted utilizing the ancient "cartoon" method from a photo taken by myself or the subject. Other pigments are added to additional epoxy layers to create the image.
My first work using this technique has hung on my wall since 2001 with no perceptable change. Below is a collection of more or less relevant technical literature.
Jim Pallas. April 3, 2012. Applegate, Michigan
Cured but uncoated urethane foam on extruded styrene foam substrate.
Illustration: "Poor Jacqueline" (48"x38"x4")
Extruded Styrene Foam: ":...foam (XPS) consists of closed cells, ...Extruded polystyrene material is also used in crafts and model building, in particular architectural models. Discarded polystyrene does not biodegrade for hundreds of years and is resistant to photolysis.
^ 14. Bandyopadhyay, Abhijit; Chandra Basak, G. (2007). "Studies on photocatalytic degradation of polystyrene". Materials Science and Technology 23 (3): 307–317. doi:10.1179/174328407X158640.
In an Off-the-record conversation with me on March 2, 2012, an Owens-Corning technician said, after qualifying that Owens-Corning does no testing of very long term (hundreds of years) product behavior in a epoxy sealed state or any kind of state, he opined that the 2" styrofoam panel "would remain dimensionally stable indefinitely."
Urethane Foam: Effects of visible light.: "Polyurethanes...contain chromophores which interact with light. When PU foam...is exposed to visible light it discolors, turning from off-white to yellow to reddish brown. It has been generally accepted that apart from yellowing, visible light has little effect on foam properties. ."
27.Discoloration of polyurethane foam". Foamex Information sheet. Archived from the original on 2010-09-26. Retrieved 2010-09-26.
28 Valentine, C; Craig, T.A.; Hager, S.L (1993). "Inhibition of the Discoloration of Polyurethane Foam Caused by Ultraviolet Light". J. Cellular Plastics 29 (6): 569–590. doi:10.1177/0021955X9302900605
" It has been reported that exposure to visible light can affect the variability of some physical property test results. ... samples should be protected from light exposure."....
"Higher-energy UV radiation promotes chemical reactions in foam, some of which are detrimental to the foam structure.
Blair, G. Ron; Bob Dawe, Jim McEvoy, Roy Pask, Marcela Rusan de Priamus, Carol Wright (2007). "The Effect of Visible Light on the Variability of Flexible Foam Compression Sets". Orlando, Florida: Center for the Polyurethane Industry.;
Laminating Epoxy: Resin Chemical Formula: BISPHENOL-A POLYGLYCIDYL. Catalyst Chemical Formula: CYCLOHEXYLAMINE. Cured epoxy is extremely stable chemically and dimensionally over long periods. Extended exposure to the ultra-violet (UV) of direct sunlight may cause some yellowing or chalking of clear non-pigmented epoxy. Addition of UV blockers ( e.q. titanium or zinc oxides and others) ameliorates this effect.
HEALTH AND SAFETY DATA
Like oil paint on canvas, extruded styrene foam, urethane foam, and epoxy are combustible. Avoid contact with open flame.
Extruded styrene foam:
The slab of two inch thick extruded polystyrene is FOAMULARŪ 150 Extruded Polystyrene Insulation Extruded polystyrene closed cell foam, ASTM C578 Type X, 15 psi minimum
• FOAMULARŪ XPS insulation is made with a zero ozone depletion formula.
• Certified to meet indoor air quality standards under the stringent GREENGUARD Indoor Air Quality Certifi cation ProgramSM, and the GREENGUARD Children & Schools Certification ProgramSM
Fully reacted polyurethane polymer is chemically inert."
23Dernehl CU. (1966). Health Hazards Associated with Polyurethane. Journal of Occupational and Environmental Medicine.
...The measured ecotoxicity is that of the hydrolyzed product, generally under conditions maximizing production of soluble species. Material is practically non-toxic to aquatic organisms.
Material Safety Data Sheet available from The Dow Chemical Company, Product Name: GREAT STUFF PRO(TM) Gaps & Cracks 24oz