painting sub frame (por-15) how much do I need

[tellyv]

Originally Posted by rjsjea

It is covered with rust? Just curious why you want to use that stuff? I have used it several times (brushed/sprayed over surface rust and clean metal) and had adhesion probs.

If it's removed from the car a sandblasting and prime/paint will look way better.

I bet two quarts would be more than enough POR15, to answer your question

I agree, I would use an epoxy primer and something like imron, they make and industrial grade imron that is cheap and its way better than por 15, I also had adhesion problems and frankly their semi gloss looks like hell!

[speedjohnston]

I agree with the semi gloss looking like hell. Its about as shiny as the black but has flat black spots in it... its weird. I would just stick to the gloss black. POR15 does not stick to other paint. It bonds to light surface rust, and if its bare metal you need POR15 metal prep. I think it leaves behind a zinc coating for it to bond to.
As allready mentioned, take the time to do the proper prep and it will be fine. Don't do it if its humid out because it actually dries faster in humidity and won't level out as well if you brush it on.
I just applied it to my cage after using the marine clean, then the metal ready and it seems pretty tough. The shop that did the cage put some POR 15 on top of some other paint in another spot and it peeled off with the painters masking tape. The parts of the cage I prepped, nothing came off even though I was scratching at it with my nails to take the tape off.
Thats my 2 cents after using it this summer. Good Luck!

[speedjohnston]

Oh yeah... as far as amount, I have a jungle gym roll cage and about half a quart did 2 coats in the whole interior. A little goes a long way.