Por 15 vs. KBS Rust Seal
I have had enormous success with POR-15. However...
First thing with POR-15 is the damn prep work. It is one of the most demanding coatings I have ever used. It wants a surface that is not only bare and dry but also free of scale and properly micro-etched. The ideal surface, imho, is steel blasted with ***-fine media, painted with salty water, allowed to take a light rust, re-cleaned and THEN apply the POR.
POR is also a respiratory hazard so I only use it outdoors and you must mind the temp and humidity gridlines for applications.
Lastly, POR is NOT UV stable, it MUST be top coated if it is going to be in contact with sunlight.
Once properly applied and top coated, I swear it will stop an anti-tank missile. I have never had to re-paint a surface coated with POR ever again thus far.
Also:
1) once you open the can, you kind of have to use the rest of it up, it does not re-cork well.
2) If you get it on your hands you need to remove it with acetone IMMEDIATLY. It says right on the can that POR that dries on you hand will never come off, you have to wait for it to wear off.
3) Apply POR with disposable brushes, don't bother trying to clean and re-use anything that touches it and that goes for clothing too.
My two cents on the stuff. -LY
I have never used KBS.