Avoiding a very expensive repair bill by using EZ-SprayŽ Rubber
The EZ-Spray® Jr. System is ideal for a variety of mold making, spray casting and coating applications. To follow is a case history chronicling how a manufacturer of supermarket refrigeration units found EZ-Spray® Silicone 35 a relatively inexpensive answer to a potentially very expensive problem.
The manufacturer has many refridgeration units installed in supermarkets throughout the U.S., with the minimum cost of a unit at $20,000. The units keep fruit and other foods cold and fresh until sold. The galvanized steel plate bottom of each unit measures a minimum of 7' x 4' (2.13m x 1.22m), with many units being larger. These plates end up being a receptacle for water condensing from the refridgeration coils as well as a combination of food byproducts.
The Problem: 8 years following installation, the galvanized steel plate bottom of the unit rusts which is not anything the manufacturer anticipated. Holes in the steel plate form and leak water and other food byproducts onto supermarket floors. This creates a rusty, oily mess in the stores that is potentially a slipping hazard for customers.
Supermarkets that bought these units were not happy and looking to the manufacturer to replace them. Other than the leaking problem, the coolers are functioning normally and replacing the units was the choice of last resort for the manufacturer. Replacing the galvanized steel bottom of each unit would have meant time consuming disassembly of mechanical cooling components at expensive after-hours labor rates (any repairs would have to be done after 11:00pm at night when customer traffic is low).
The thinking then turned to a coating of some kind that could seal the steel plate stop the leaking and protect what remains from further degradation. The manufacturer contacted Smooth-On for a material solution and we established the following criteria for selecting a coating:
It had to seal the plate and provide a barrier that withstood water and food byproducts for as long as possible.
The coating had to be safely applied in grocery stores in proximity to people and food.
Time spent repairing each unit had to be minimal, so the coating had to be fast curing so that the repair crew could be in and out of each store quickly.
After considering a variety of materials, EZ-Spray Silicone seemed to be the most promising candidate. The refridgerator manufacturer commissioned a laboratory to test the cured silicone for resistance to acids (citrus), animal fats, vegetable oils and other food byproducts at different temperatures. EZ-Spray Silicone showed no sign of degradation during prolonged exposure to these material variables.
As the step by step pictorial presentation chronicles, the EZ-Spray Silicone solution worked flawlessly.
Total repair time including disassembly of the refridgeration unit, cleaning the metal plate, cutting and installing the pre-formed silicone sheet, applying EZ-Spray Silicone rubber and reassembly of the unit – 90 minutes.
Number of refridgeration units needing repair – over 1,200 units located at 280 stores.
Amount of EZ-Spray Silicone used to repair one refridgeration unit (including pre-formed sheet) – Just over 2 Cartridge Units or 6.5 lbs. (2.95 kgs.)
Nice Things To Say
Repair personnel commented
"Instead of requiring 5 guys working all night to replace the steel sheeting, the EZ-Spray System let us finish the job with 2 guys working 6 hours in each store. It's amazing, there is no smell or cloud to worry about. If the compressor did not make noise, customers wouldn't know that we were even there."
The manufacturer of the coolers calculates that using EZ-Spray Silicone to solve this problem saved them over 1 million dollars vs. the next least expensive repair alternative.
1 - After hours repair using EZ-SprayŽ Silicone rubber as a coating. Above: preparing refridgeration units for cleaning and application of spray rubber.
2 - Galvanized steel subjected to years of acids and other food byproducts causing the steel to rust, corrode and leak.
3 - The steel is cleaned thoroughly. Pre-formed sheets EZ-SprayŽ Silicone are cut to conform under and around pipes and coils. Silpoxy Silicone Adhesive is used to secure the EZ Spray Silicone to the steel base.
4 - EZ-SprayŽ Silicone is self leveling and uniformly coats the metal surface. Rubber is also used to encapsulate the pre-formed silicone sheet.
5 - Spray tip allows precise delivery of material into hard-to-reach areas.
6 - Once all surfaces are coated, a heat gun is used to reduce the cure time of the rubber.
7 - The circulating fan assembly is put in place before the food display shelf is replaced.
8 - 4 units done at this store...only 1,196 units left to go. Still, the EZ-SprayŽ rubber system remains the less expensive alternative in solving the problem by far.