POR-15 question.

Heres my situation. The bottom of my car is some surface rust, some clean/painted metal (after stripping the undercoating) and some new sheetmetal. The trunk and rear wheel wells seem to have the most surface rust. My million dollar question is can I do the whole bottom of the car with POR-15? I know their tech sheet says to clean it and use there prep stuff before applying but I want to make sure it will stick to the fresh sheet metal and and painted surfaces.

Thanks,
Todd

 

Buddy of mine completely stripped the underside of his car and POR-15 it. Still holding up very well. Now none of it was fresh sheet metal though.

 

Por-15 needs an etched surface to adhere properly. Rust is a natural etch so will stick to that. New metal will need to be chemically, or mechanically etched for proper adhesion, and don't even think about putting over painted surfaces, it won't stick well, and doesn't give the protection you want.

B***ically you need a clean etched surface for Por-15. If you do use it, brush it on, and don't get it on anything you value cause it's hell to get off....Don't even think about spraying it unless you have a fresh air respirator.....

 

The prep **** that POR-15 sells is supposed to be an etching agent also. So I guess I could use por-15 on the rusty and fresh sheet metal surfaces and fresh paint over the old paint.
I work in the marine industry and have "access" to International brand marine grade epoxy paint it is good stuff and holds up well. I may use that on the painted parts and as a topcoat for the POR-15.
Todd

 

POR-15 is great for stuff like that. a buddy of mine did the entire roof of his car in it before painting it.

tok

 

I used to know the VP of miricle paint(same exact ****). Best thing to do is strip good metal down n put outside to rust alittle. adheres BEST to surface rust. PERIOD. If you spray, cut about 4:1 with laquer thinner. and if u wanna topcoat later, lay a good couple coats of primer when the POR15 is still tacky. way easier to sand/scuff primer.

 

Like everyone has said dont get the metal to clean or it wont stick for ****.
I did some floor pans and had a section lift up like a piece of vinyl.
It just peeled right off. POR is great stuff but on new metal or metal thats cleaned very well I would epoxy prime it first.

 

Todd,
If you decide to use the POR-15 make sure that you apply the top coat while the POR is tacky or you will have to scuff it after it dries for good adhesion.
Most marine paints are great and would make a good under body coating.

Their Metal Ready is a great prep...keep it wet and rinse completely and dry before applying the POR-15...