so leave POR 15 as is or cover it with some other paint when using in on the chassis area? I am talking floor pans, inner fenders etc.
I know lots of guys do the entire underside with it and are happy. It is kind of a pain to use so some people only do the rusty parts, and then paint over everything to make it all match.
i have found that por 15 sticks the best to porous stuff, even sanded metal needs etched for it to stay like it was intended.
but the worst part is that other paints do not like to stick to it.
the first time it is hit with a power washer the paint (no matter what kind ) will peel off from the por 15.
the first time this happend to me it came off in big sheets. this includes under coatings.
the paint and undercoatings will stick to the por 15 primer good but not to the por 15 paint very well.
the por 15 primer and paint will gum up sand paper if you need to sand it (i did not like this).
from what i found is that if you want to cover it with a color coat, use the por 15 stuff before painting.
great stuff for cast parts but i will not use it on sheet metal any more.
anyone else have any problems like this.
i am probably doing something wrong or maybe i got a bad can, but i do like it on cast parts.
floor pans under the carpet and inner fenders i would not paint over it, but it may still fade and dull with time.
i am going to leave the bottom of the car alone and just leave the por 15, that way if i need to touch up or paint the under side again i know that the por 15 will stick to itself.
i assume that you are concerned about the uv fadeing effect with the rust preventer por 15.
instead of the por 15 topcoats.
por 15 topcoats do not need covered.
thanks m.p.
Has any body ever had rust problems following the use of POR 15? I am under the impression that it really works.
por 15 will not stop a piece of cheezy metal from rusting again.
if you just paint over the rust on sheet metal with rust on it , it will rust under the coating.( i know it says paint directly over rust but there is and are limitations and will depend greatly on the prepping before coating.
since por 15 will not crack chip or peel, the moisture will migrate from a sharp edge or a scratch and work its way under the coating and work there untill it lifts off a big enough piece too come off.(make sure the edges of sharp corners and cuts are well coated, this is where it all starts rusting again.
when the paint finnaly flakes off, it is still stuck very well to the rust that peeled away.
regular paint will at least crack and vent out or chip off in a small piece.
some have used this stuff (including myself) on the insides of pannels in those spots that you can not get to.
even with rust converters and what ever else it still will rust under the coating.
i have used this stuff the right way and out of curiosity i have tryed it the wrong way (takeing short cuts in prep.).
i know what this stuff works on and what it will stick to.
from now on i will use the stuff on pourious parts such as cast or only sandblasted cleaned both sides and metal etch sheet metal.
IE: if you have new floor pans in your car and you just paint them with por 15 with out etching them or sand blasting or at least give it a good fine rough surface to grip.
then you could have a problem in the future. especially with power washers…
por 15 does not like to stick to non etched surfaces .
metal is still to shinny for por 15 even with 80 grit paper or 100 grit papers. hence the reason for the metal etch that they sell.
it’s weird cause this stuff will glue the lid of the can down so good that the only way to get the paint out is to punch a hole in the can.
i have used this to glue torn weather stripping back together as well as glue the butt ends together after installing and it will not come back apart.
got some torn black seats? once two parts are overlapped and glued with por 15 the joint will tear around the joint before delaminating.
it will not patch an inner tube but it will glue two pieces together.
i painted an ugly tire once with it and it stay very black and shiny.
painted some radiator hoses too.
in non rust belt states i think the stuff would last forever.
Wow thanks, that is a very good post. I have a newly acquired rusty car, and it has me a bit nervous. I have never dealt with this much rust before. We plan to do massive amounts of cut and paste (weld actually) metal repair but there are all those places you really can’ get to. Maybe with me living in AZ it won’t matter.
you should be better off than me there in az.
i lived in ok. for a few years and had a ranchero. i could drag stuff across the bed and scratch it down to metal and to my amazment it was still shinny the next day or even the next month.
brought that rust free truck up here and scratch the bed and it will turn orange the next day. in the summer i might add.
in fact the truck started to bubble and rust within just a few years up here, never drove it in the snow but it had to sit out side during the winters, i sold it.
6 years ago i bought one from washington state it now looks like a rust belt car.
i had even painted the insides of the quarters with por 15.
but i do have to drive it in the winter some times.(it was a cheap work truck even after having it shipped here.
it kinda sucks being a car nut here.
so now i store my nice summer cars in a garage for the winter.
i will also add that az rust is allot eazier to fix than rust belt rust.
it just goe’s real deep and wide here where west coast and southern cars the rust is not spread so bad around the rust holes.
where i might have to cut off an extra 2 or 3 inches around the hole you might get away with 1/2 inch cut.
not trying to be a one upman here but thats the way it is and it sucks.
been fun …mick