I'm planning on doing some touchup on the bed of a Very Large dump truck and after pressure washing and brushing off the leftover chipped paint, I plan on using Ospho on the exposed rusted spots. After the 24hr waiting period, I want to paint directly over the Ospho'd areas.

Trucks way too large for me to beat out all of the dents, properly etch & prime and then paint. Looking at the many places where the paint is chipping, it came factory paint without being primed. Already have PPG enamel paint match and mainly just want it look good from a distance and OK up close.

Question is, will the Ospho give the paint any odd reactions. Don't want to go to all the work and have is start bubbling a week later.

Carlene
(Just what I need - another Project)

 

If you are using the Ospho brand, they claim their product IS a primer and you can paint over it. Other brands that are similar recommend that you primer before painting. To be sure, maybe you can e-mail the company who makes Ospho.

 

Thanks for the Quick response - am planning on getting started on it this weekend.

Carlene

 

>I'm planning on doing some touchup on the bed of a Very
>Large dump truck and after pressure washing and brushing off
>the leftover chipped paint, I plan on using Ospho on the
>exposed rusted spots. After the 24hr waiting period, I want
>to paint directly over the Ospho'd areas.
>
>Trucks way too large for me to beat out all of the dents,
>properly etch & prime and then paint. Looking at the many
>places where the paint is chipping, it came factory paint
>without being primed. Already have PPG enamel paint match
>and mainly just want it look good from a distance and OK up
>close.
>
>Question is, will the Ospho give the paint any odd
>reactions. Don't want to go to all the work and have is
>start bubbling a week later.

Ospho has very similar qualities to navel jelly... diffrence being serious rust gets converted to a puddle of black goo. Puddles of Ospho that have spidded down from my interier bed sides to the bed floor have puddled up and formed this hard black seal. The areas of light rust, however didn't seem to be converted to the same hard black puddle of goo. Excluding the color change. This puddle didn't form in one day though, the dry time was 2 to three days.

Based on my observation, the Ospho has very little reaction with paint, Even recently primered regions, the primer wasn't removed. Further i've observed this product on the rusty interior bed sides, as well as the wheel wells. My purpose is slightly diffrent though, using this to assist the process of removing rust before wire brushing, and providing color contrast so my color blind eyes can better see problem areas.

But I don't honestly think that a paint chewed up rusty bed would be fixed in 24 hours. I think this would call for for repeat applications over a period of a few days for proper penitration from skin to metal layer.