POR-15 under body filler??

[bluegrasscharger]

I have begun the body work on my charger.  I was wondering if you can treat rusty areas with por-15 and then put body filler over it?  Also after I weld in patch areas should I treat them with por-15, will the body filler stick to it?  I am mainly considering this in the sail panel area, around the back/front windows, and on the roof where the vinyl top caused it to rust.

[tan top]

sorry but don't think this is the answer your looking for ,  but !
  don't do it !  also never put filler over rust  ,  

[bluegrasscharger]

I wasn't going to put bondo over rust.  The sail panel area had some minor rust that caused the old body filler to bubble.  I have grinded and sanded the old factory bondo away to get to the original seam.  I grinded the rust from the area but it is still black or etched from the old rust.  Same with the roof rust.  The rust is gone but is black not shiny metal because of where the rust was.  Seems like I should put something on these areas to prevent the rust from returning.  In the case of the sail panel I was thinking of putting POR-15 in the seam area and then putting the body filler over it.  Or should I just use some sort of rust converter?

[green69rt]

sorry but don't think this is the answer your looking for ,  but !
 don't do it !  also never put filler over rust  ,  

I have to agree.  No filler of any kind over rust.  I personally have used POR15 a lot and have had good results, but only over rusted or cleaned up areas and never where I plan to fill, solder or weld..  If rust is the problem, I've always ground out the rust before filling.  Anybody have a solution for this threads problem??

[bluegrasscharger]

Guys I am not putting bondo over rust!  After I grind the rust off, the metal is still etched from where the rust was.  It just seems like treating these areas would be a good idea to keep rust from coming back.  Here are some pictures below to show you what I mean.

[bluegrasscharger]

Here's another pic.  The rust is gone but the metal is etched from the rust.  Should I use por-15 to treat this area or some other type of rust preventative. 

[HOTROD]

No that is still rust ! Had that on another car under the vinal top I just sand blasted it filed and primer .
No rust come backs 10 years and no vinal top eather !
I use Dupli-color Self-etching primer (green) on bare metal !!

[green69rt]

Ok, if the metal is just etched then what about using a epoxy 2 part primer.  Someone now makes one in a spray can.

The thing with POR15 is that is it isn't applied right and starts to shed then you're screwed.  If you really want to use it then follow the recommendations on their web site.  Scuff up the metal with about 200 grit sandpaper, clean with their degreaser and then treat with the "Metal Prep".  Do not skip the "metal prep", it takes the metal to a acid pH and this is absolutely required to make sure the POR15 sticks right.  Then scuff the POR15 again before coating with primer.  Then use the filler.  

I have to believe that others would say....use the primer directly on the metal then filler.  That is actually what I would do.  Here's one possibility::

http://www.autobodytoolmart.com/spray-max-2k-epoxy-rust-cure-primer-3680032-p-14526.aspx

[tan top]

No that is still rust ! Had that on another car under the vinal top I just sand blasted it filed and primer .
No rust come backs 10 years and no vinal top eather !
I use Dupli-color Self-etching primer (green) on bare metal !!

yep still rust !!  it needs   blasting , acid , wirebrush , carbide bit on  a die grinder , or what ever combination works on this area !!   to removed all traces of the discolored metal (rust)  , then bondo 

[bill440rt]

Best method is to remove the rust ENTIRELY & prime with epoxy primer.

If you do choose to use POR-15, please check out their website for their other products. They have other products (self-etching primers, body fillers, seam sealers, etc) that are designed to go over the POR-15 paint.

[johnnycharger]

I have heard that POR15  can't go over any existing paint either. You may want to look into" Rust Dr"

[elitecustombody]

I agree with guys above, it's still rust. It's area that is prone to rust, so if you don't want to be doing this again,blast it,cut it out,but do not cover it up!If you still want to use POR15, follow instructions to the T.But I would use epoxy primer over blasted clean metal 

[Shmity1]

What about a coverter then seal it with a primer?