ospho and epoxy primer

[Anonymous-0]

I treated my rusty tractor with ospho, and want to prime with ppg 170 epoxy primer. What surface treatment would you do before applying the primer? Just sand the ospho coating a little? Nothing? TIA

 

[Brokengun]

I too would like to know the answer to this question.

I have started using ospho on some rusted areas and I find the ospho treated areas to be rather rough.

Is it necessary to sand if using ospho?

Some times its almost impossible to sand some areas.

I’m working on an auger right now that has a lot of hidden rust areas that can’t be sanded or brushed and disassembly is out of the question.

So can a coat of ospho be sufficient before painting?

Does ospho always need to be washed off or can you let it dry then paint over it?

 

[SWMO]

Have never used this product, but this should help.
Directions for use
For Application Questions Not Answered Here Call Factory Direct at: 216-771-1590


RUSTED METALS - OSPHO is a rust-inhibiting coating - NOT A PAINT You do not have to remove tight rust. Merely remove loose paint and rust scale, dirt, oil, grease and other accumulations with a wire brush - apply a coat of OSPHO as it comes in the container - let dry overnight, then apply whatever paint system you desire. When applied to rusted surfaces, OSPHO causes iron oxide (rust) to chemically change to iron phosphate - an inert, hard substance that turns the metal black. Where rust is exceedingly heavy, two coats of OSPHO may be necessary to thoroughly penetrate and blacken the surface to be painted. A dry, powdery, grayish-white surface usually develops; this is normal - brush off any loose powder before paint application.


NEW METALS - For new ferrous or aluminum metals: remove dirt, grease, or oil; apply OSPHO, let dry overnight, then paint.


GALVANIZED - where appearance is important, apply one coat of OSPHO, let stand for approximately thirty minutes or until metal is etched. Flush with water, avoiding damage to adjacent areas; or wipe to a smooth finish, let dry, then paint. Where appearance is not important, one coat of OSPHO is recommended to thoroughly coat and etch the metal. Let stand overnight or until completely dry. Brush off any loose powder before painting.


A typical paint application will last much longer after an application of OSPHO because subsequent paint coatings attach themselves so tightly that moisture and oxygen cannot attack the metal. OSPHO is water-thin, and therefore goes on easily and covers a larger area than paint. One gallon covers approx. 600 square feet. Historically, best results have been achieved using an oil-base primer and topcoat. Test a trial sample before using under epoxy or latex-base paint applications. OSPHO is equally effective for exterior and interior work alike and is highly recommended as a pre-treatment coating by leading paint manufacturers.


For best results, use OSPHO at temperatures no lower than 36 degrees F. Excessive dew and humidity may prolong drying time and cause powdery buildup.


Spray equipment should be flushed out with water after using. Clean brushes with water. Avoid getting OSPHO on adjacent areas such as painted surfaces, concrete, masonry and stonework. If splashing occurs, flush immediately with water to remove.


WARNING: OSPHO contains phosphoric acid. KEEP OUT OF REACH OF CHILDREN. If taken internally give large quantities of milk or water. Call physician. Avoid contact with eyes. In case of contact, flush with water. Prolonged exposure to skin may cause irritation - use rubber gloves or other forms of skin protection.



SAFELY DISSOLVES BLEEDING RUST FROM MANY PAINTED SURFACES:
CAUTION: paint composition & quality vary greatly. A check should be made by testing OSPHO on a small area. Dulling or peeling may occur in some finishes. The manufacturer assumes no liability for damage to finished surfaces.

 

[charles todd]

I use this product on all my projects. I apply 2-3 coats and let dry overnight. Then I use a maroon Scotchbrite pad on it to remove the powered residue. So far all my paint has held tight, no lifting. As for the roughness, the sanding may help as will using a surfacer after the prime coat.

Good luck,

CT