SPI

Waterproofing

Polyshield Protects Water Irrigation Flumes from Leaks

Originally designed during the Great Depression, the Columbia Irrigation project supplied farmers with water from the mountains. Every year more and more steel flumes were added to the system as the demand for fresh water increased. When corrosion started to eat away at the steel, the call went out to Specialty Products.

Job Description: Originally constructed in 1984, the flume's gal- vanized steel structure was exces-sively corroded and in need of an upgrade. POLYSHIELD SS-100™ was chosen for the project.

Preparation consisted of grit blasting down to 3-4 mils anchor profile. One flume was so badly corroded that grit blasting actually blew holes in the steel. POLYSHIELD SS-100™ was used to coat the outside of the flume. This section then acted as a mold-form for the interior to be blasted and sprayed. The result was a new flume section consisting of SPI's POLY-SHIELD SS-100™ with AE-4 applied at 50 mils to the outside and 100+ mils on the inside of this section.

Follow-up Inspection: The flume was inspected in August 2000. An SPI technician reported the absence of any leaks or other visible problems.

Other Coatings Evaluated for Project: Several repair methods were evaluated for this project. The installation of a metal sleeve was considered but ultimately rejected due to the potential problem of corrosion between metal layers. Replacement of the entire flume was also rejected due to cost. POLYSHIELD SS-100™ was determined to be the most economical.