Ethanol tanks are common in the gas and fuel industry. And painting them is a common maintenance procedure. But commercial painting contractors need to be aware of the fungal growth that’s common with ethanol, and what types of coatings will resist its growth.
Baudoinia compniacensis. You probably don’t know what this is, nor do you know how to pronounce it. But this is a black fungal material that likes to grow on ethanol tanks, distilleries, and your uncle’s old whiskey barrel. But no matter which substrate you’re painting, be sure to have an industrial thermometer handy to get the temperature reading on the surface.
And like most painters, this fungus likes alcohol. So if there’s a business that has holding tanks for ethanol, you can be sure to expect to see this black fungus in a few short months or a few long years.
But there’s a wide gap in that time frame. And which coatings get applied to the tanks will ultimately dictate how long the owner has before they start to see their precious tanks get consumed by the invasion of the fungus.
There are a few preventive measures one can take. And the most popular is power washing with a detergent like Simple Green.
Power washing will remove the fungal growth, restoring the appearance of the tank prior to the fungus growing on the organic coating.
But, power washing won’t prevent the fungus from returning. And if the terminal has the funds, then the next best option is to paint the entire unit.
But which industrial or commercial paint to use?
There are a few systems on the market that can provide the solutions the tank owner is seeking. Sherwin Williams has a HS Polyurethane. This urethane product, by itself, it a typical urethane. However, Sherwin Williams offers a Mildew Resistant additive. This additive is an inorganic compound, that prevents fungus and mildew from growing.
But there are some drawbacks with using this paint. And the biggest one is workability. It doesn’t offer the self leveling properties that you’d prefer in a top coat, making brush marks and roller laps common in the finish coat.
But other than that, the mildew resistant urethane isn’t a terrible choice. Another option, and what appears to be the best option is PPG’s PSX700.
The PSX700 is a polysiloxane. Polysiloxanes are great for color retention, and for adhesion. They’ll maintain their integrity in the most difficult environments, including sea time, and even space.
But the reason it’s so beloved for coating ethenol tanks is that it’s made from an inorganic structure. And that inorganic structure prevents the mildew from having anything to feed on. Which ultimately allows the tank to remain fungus free throughout the duration of its existence.
Here is a picture of tank that is 2 years old with PPG’s PSX700:
And as the photo clearly implies, the PSX700 does a great job resisting mildew growth.