Sherwin Williams "OSPHO" has anyone used it ???

[Highbanked Hauler]

  It works great treating minor rust and keeping open metal from rusting,  The instructions say put it on with a spray bottle till the metal is all wet and let it dry wipe off any residue and paint over it.  NOW I have been advised to re wet the coated metal with the material and flush it with water to neutralize the acid before painting. If you have used it what procedure did you use as I hate to put water on open metal. Thanks.

[green69rt]

Haven't used it but there are several products around for rust prevention and many of them are some form of phosphoric acid/zinc phosphate.  The acid dissolves rust and etches the underlying metal and the zinc phosphate pickles the metal to prevent future rust.  When you apply it and it dries, it leaves some zinc phosphate residue that you need to wipe off so the paint will stick.  Use a damp cloth and dry the surface immediately.

[71charger_fan]

We used to use it on the SeaLand container ship I worked on back in the '70s until the safety office took it away from us. SeaLand had a standard set of colors, so our chief mate at the time worked out a system where he'd order a non-standard color as his code to a friend in procurement to get us some OSPHO without it showing up by name in any order documents.

[Highbanked Hauler]

We used to use it on the SeaLand container ship I worked on back in the '70s until the safety office took it away from us. SeaLand had a standard set of colors, so our chief mate at the time worked out a system where he'd order a non-standard color as his code to a friend in procurement to get us some OSPHO without it showing up by name in any order documents.

   cool, did you spray it on let it dry and paint or did you wash over it then paint ??