Frequently Asked Questions
Coverage:
Quart: Approximately 150 sq. feet per quart
Gallon: Approximately 600 sq. feet per gallon.
Can it be used on cast iron or steel, does it need to be rinsed off, and what type of primer should be used?
It can be used on both cast iron and steel, and it does not need to be rinsed. It is a rust converter. Use the primer that is right for the job - a primer for metal, in this case. It doesn't matter whether it is oil or water based primer, as most in CA are water based.
Can I weld on top of metal after I have applied prep and prime?
If you are not coating after using the Prep and Primer, then you can apply, rinse with water, and dry off immediately (or use Jasco Metal Etch.) Prep and Primer is normally used under coatings. There shouldn't be any welding reaction. Prep and Prime does leave an iron phosphate layer, though, which would need to be removed since welding needs to be done on bare metal.
I have applied 3 coats, left it on the surface for about 2 days and some spots did not change color and still look rusty - Why?
Prep and Primer will only react with Ferrous Iron, (rust). It will not react to paint, or if there is grease or oil on the surface preventing it from coming into contact with the rust. More Prep and Prime is not necessarily better. It can change anywhere from a white powder to a black substance, depending upon the amount of rust and the iron content. If it is washed off, it may not react to the deeper portions of rust.
Can I use an airless sprayer?
No. These sprayers are made of metal. The product will instantly react to the metal. A low-pressure sprayer is usually made of plastic and is hand pumped. Also, an acid should never be sprayed.
I have applied the Prep and Prime to some painted areas and now the paint is tacky. How do I fix the paint?
The Prep and Primer will only react with metal compounds, and will not react on the paint. The paint isn't tacky - it is the excess Prep and Prime that did not react. Just clean off the surface with either Paint thinner or hot water and regular Tri Sodium Phosphate and let dry.
The product came in contact with concrete and I let it dry and now the concrete is white. What can I do?
Prep & Prime is an acid, not a coating. It has bleached the concrete, not much can be done at this point.