InfraStructures - September 2013 - Toronto’s University Avenue’s Famous Statue, Rising, Receives a Magical Transformation

Toronto’s University Avenue’s Famous Statue, Rising,
Receives a Magical Transformation

EcoJet demonstrates their new “dry ice blasting (DIB)” technique, which restored and cleaned the esteemed Zhang Huan’s art sculpture, Rising, located at Richmond and University in Toronto. The large-scale exterior sculpture measures about 20 m x 20 m, weighs approximately 22 t and resides just north of Adelaide Street on University Avenue.

Rising was installed only a year ago, but even in this short time period, its exposure to the sidewalk dust, exhaust soot, brake dust, tire rubber, and acid rain of Toronto’s busy University Avenue, had made cleaning a necessity in order to preserve the original shine of the sculpture. This approximately $5,000,000 piece of art, created in 2012, was a perfect candidate for this new dry ice blasting technique.

Dry ice, which is commonly used in refrigeration, and for stage special effects, is now being used in wide array of restoration applications, and in the cleaning of industrial equipment. Dry ice is composed strictly of CO2. No water, or additional abrasives are used in the DIB process, which is what makes it so effective in the cleaning of heavy duty, and delicate surfaces – even live electrical components. It is environmentally friendly, sterile, non-waste generating, non-conductive, non-abrasive properties make DIB an indispensable method of cleaning things that cannot be cleaned by any conventional means.

EcoJet uses two different techniques, pellet blasting or snow blasting. Dry ice pellets are used on tougher contaminates, and snow is used when a gentler approach is necessary to preserve the surfaces of the substrate being cleaned. Pellets were used for Rising, which gently and effectively cleaned and restored the sculpture to its near original beauty.

“The use of Pellets for this dry ice blasting worked very well. This DIB process is still so new and the applications are endless. This sculpture demonstrated how delicate yet aggressive this process is,” says Mike McGraw, proprietor EcoJet.

About the Sculpture
Rising, a polished stainless steel sculpture, is comprised of countless doves (the international symbol of world peace), and a twisted tree branch that resembles the body of a dragon. The sculpture draws an analogy to the fragile conditions facing the planet. The artist advocates protection for the environment, so it is quite fitting that a cleaning approach was chosen which aligns itself so well with the same philosophy.

About the Process
DIB is a form of abrasive blasting, in which hard pieces of frozen CO2 pellets are shot at a surface with high pressure air. The extreme cold (-79°C) causes the contaminant to become brittle by causing a thermal differential between the layer of debris and the substrate. The cold shrinks the debris causing it to contract, and weakens the bond with the substrate, which when combined with the micro-explosions created by the sublimation process (800 x/ms), the contaminant explodes from the surface without altering or abrading the profile of the underlining substrate. The CO2 pellets can strip paints, remove grease and oil residue, and could even remove the ink from a business card while causing minimal damage to the paper.

DIB causes no additional waste bi-products like traditional sand and soda blasting. The CO2 it uses is recycled CO2 which is captured as a bi-product from other manufacturing processes, so it emits no additional greenhouse gases. DIB beats other processes e.g. traditional forms of abrasive blasting like sand, or soda blasting, in that the dry ice media sublimates directly from a solid back into gas once it makes contact with the surface. This means no secondary waste is created, which makes it perfect for cleaning things like complex pieces of machinery. DIB kills mold, and bacteria on contact and is extremely practical for food processors, and bacterial mold removal.

Source: EcoJet