Tuesday, Mar 24, 2020 at 18:51
Gronk - I saw and read your post. However, dust from a passing dust storm landing on canvas is not necessarily the same as the red gravel dust and iron ore dust thrown up, when travelling over an extended period - and which red gravel dust/iron dust also has a greater iron oxide content, and an extended time in contact with the canvas, to aid in chemically fixing it to the canvas.
I've spent a number of decades in the mining industry, operating and cleaning the vehicles and equipment therein, and after a short time in contact with any surface - be it paint, metal, plastic, or canvas - the iron oxides become firmly bonded to the underlying substrate, and 98% of the time, only treatment with a chemical cleaner will remove it.
There are literally dozens of businesses out there with a wide range of chemical cleaners, all designed to attack the red gravel dust/iron dust problem.
If it was easy to get the red dust staining out, there wouldn't be the range of chemical cleaners on the market, all specifically designed to treat the problem.
The problem is, there is no chemical cleaner that is safe to use on canvas.
You can buy Starbrite Sail and Canvas cleaner, which is a concoction designed to clean canvas - but it only contains alcohol ethoxylate, an emulsifier and surfactant, and pentasodium triphosphate, the basic ingredient of all laundry/washing powders.
On that basis, scrubbing your stained canvas with a bucketful of water containing a scoop of laundry powder - and then hosing it and scrubbing it again with clean water, is about the best result you can end up with.
Cheers, Ron.
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