Stained Ipe

[Richard 17]

Need Help

Brand new commercial install of Ipe, roughly 1500 Sq. Ft.   9th floor exterior patio downtown Toronto Condo building.

Something was stored on it. In one spot (not in the picture) there is clearly the shadow of a metal shim. Not sure what exactly was stored or caused the stain in the picture. We tried washing it with F10  and F18 followed by F8. Tried sanding. NOTHING. Any pearls of wisdom ?

Edited September 16, 2020 by Richard

[Beth n Rod 1,279]

Rust is typically removed with Phosphoric acid.
You mentioned a metal shim so that should be a good course of action. More dwell time as well. This stain looks to have been absorbed over time so it will have penetrated the pores of Ipe which is unlike soft woods which have elongated fibers instead.
The sanders may come in handy after again.

Now, as to the photo, this looks to be a caustic stain. Given it in a public use area, who knows. I would try f18 alone. Prepare you may have to do entire lengths of boards to keep the appearance more uniform. Brushing may also be helpful. Neutralize after.

Rod & Beth