Is the frame exposed to uv/sunlight where the rust has bled through? If so, then you must know that the por 15 is sensitive to this and uv can cause it to degrade. That is why they recommend a topcoat. Just a thought. I had no problems with their stuff, but used the metal ready as well.
I read the part about the sheet....just don't know if that was enough to protect the surface w/o topcoat.
Hank
The myth that UV Rays degrade the durability of POR-15 is one of the biggest on this site.
Quoted from the
POR-15 Application Sheet:
(Second Page, Left Column, About Half Way Down)
WILL THE SUN DESTROY MY POR-15 COATING IF I DON’T TOPCOAT IT?
No, your POR-15 protection will remain, but the sun will change its appearance cosmetically. That’s why we recommend you topcoat it.Another Quote from the
POR-15 Application Sheet:
(Second Page, Left Column, Near Top)
WHAT IS THE BEST SURFACE ON WHICH TO PAINT POR-15?
POR-15 likes rusted surfaces best. Seasoned metal and sandblasted metal are also good. POR-15 does not adhere well to smooth, shiny surfaces, but will adhere well with the use of Marine Clean and Metal Ready preps. A Link To All Information About All POR-15 Products For my frame we sand blasted, brought home on open trailer while it was raining. After it was home it was outside until we were ready to paint. Then the night before we pressure washed it with a diluted Marine Clean mixture as per the directions. Then inside over night, one coat applied and second coat applied. Did this in August of this year still no problems.
