The Stovebolt Site Forums The Shop Area Paint and Body Shop What's Your Opinion of this New Product ?

Recently a neighbor recommended OSPHO, a product that bills itself as a primer for rusty metal. It chemically converts iron oxide (rust) to iron phosphate. This allows for any paint to better adhere to the OSPHO-treated rusty spots. It was pretty inexpensive and looked like a good approach. My tractor-restoring neighbor swears by it.

Does anyone have experience or opinions on this type of product? How does it compare to rust encapsulation? I welcome your responses.

Converting iron oxide (rust) to iron phosphate is what most of the metal treatment products do. They have various trade names such as metal prep usually contain a buffered phosphoric acid.

You brush or wipe this product on...doesn't it leave a rough coating? I'm concidering trying this stuff...my 52 is sanded down to bare metal in places and I won't be painting for a couple weeks. Hitting the spots with Scotch-brite is getting old.

Russ-

You are correct. It is considered a primer or surface treatment. Yet, it prevents further rust and allows you to buff or sand lightly before a final coat of whatever.

I've been using the stuff for years, works great! I stripped a "rust-free" 55 Belair to bare metal a couple years ago and left it sit under an open carport,uncovered for almost a year as I started on some other projects. A bad habit of mine! :rolleyes: Anyway, I wiped the 55 down with Ospho about once every couple weeks and it is still rust-free! During some of our fine humid and rainy weather we get here in Georgia, the body would be covered with codensation but never developed any surface rust! I'd have to say, that pretty much sold me on Ospho!

So, every couple of weeks for a couple of years? You rubbed the Ospho on like 50 times?

Amazing the car isn't rusting though.