Problem Solving Forum
February 21 - February 27, 2016
Alternatives to coal tar epoxies in wastewater/sewage applications have been in service for a number of years. From experience, which coating types with what fillers at what thicknesses (over steel) have performed best?
Todd Theis of Gulf Coast Paint Mfg., Inc. on
November 7, 2016:
I would recommend a cycloaliphatic epoxy, applied ...read more I would recommend a cycloaliphatic epoxy, applied in 3 coats at 7-10 mils DFT per coat.
Anthony Koontz of Sherwin Williams on
October 20, 2016:
I suggest a solvent-free elastomeric polyurethane ...read more I suggest a solvent-free elastomeric polyurethane at 60-80 mils dry film thickness.
Tom Schwerdt of Active Transportation Advocates on
May 12, 2016:
Why would you switch from coal tar epoxy to coal t ...read more Why would you switch from coal tar epoxy to coal tar urethane? Coal tar is unpleasant to work with and a carcinogen.
Robert Olmstead of Olmstead Business Services International (OBSI), LLC. on
May 6, 2016:
I am aware of many waste treatment/sewage plants g ...read more I am aware of many waste treatment/sewage plants going back to 1989, both domestically and internationally, that have successfully specified and maintained ongoing use of 2 coats of coal tar urethane (CTU) at 10-12 mills DFT per coat, on concrete clarifiers and similar structures. The coating is based on a single-component, moisture-cure urethane (MCU). On steel they use same spec over a MCU zinc or MIO Zinc (micaceous iron oxide) combination primer, at 2-4 miles DFT. They also use the same zinc primer under a MIO-rich intermediate (3-5 miles DFT) with an aliphatic MIO-rich MCU topcoat (2-4 miles DFT) for areas above the water/sludge line for severe chemical and abrasion resistance. The material is conventionally applied. It must be high solids (>62% solds by volume) and VOC-compliant in all 50 states. These systems are well established and readily available in the marketplace.
bart de cremer of acotec on
April 25, 2016:
i suggest a solvent-free epoxy with a DFT of 1000 ...read more i suggest a solvent-free epoxy with a DFT of 1000 microns, a proven one-layer coating system to be applied by brush and airless spray with single- or plural-pump type Graco or Wiwa.
Feng Min of Andritz Hydro on
April 22, 2016:
I suggest a vinyl ester resin with glass flake fil ...read more I suggest a vinyl ester resin with glass flake filler at 300-1500um.