Technical Screwed by POR-15 Metal Prep??

In the process of painting my car, which I chemically and mechanically stripped entirely down to bare metal, I was told by the paint supplier to apply POR's Metal Prep to create a phosphoric coating that would need to be washed thoroughly after it remained wet on the surface for 15-30 minutes. That done, I should next have to clean with a wax/grease remover and apply my filler/primer prime coat.
Days after I finished rinsing the Metal Prep, I noticed a golden tint over most of the car. At close examination it appears to be veins of surface rust (see pic).
Called POR and they told me it is only made as a prep for POR-15 rust paint and not to be used directly under other paints.
Time wasted, labor wasted...now I have to sand entire car to get rust and this crap off the car.
Any suggestions as to what I should use as a rust converter before applying paint?

Thanks

 

Ummmm why would you think POR-15 product would be useful cross-product?
Now you can paint your whole car with POR-15
POR-15 did not SCREW you! You didn't read instructions
I use their product, properly, all the time and it is great stuff.

 

My understanding is that the rust converters work if the primer coats are applied soon after. They don't keep rust from coming back to bare metal.

 

Yeah... I would 80 grit all that off, use wax and grease remover on the surface, and put down a coat of epoxy primer. I use 5 star primer, which is a hybrid primer that acts according to how it is mixed. You can use it as an epoxy primer/sealer or as a high build primer.
Remember: A paint job is 10% what materials you use and 90% knowing how to apply them/proper prep.

 

Hmm. Sounds like it was your paint supplier who led you astray. Nothing to do really with POR-15 who seems to have told you the truth. Sorry you have a problem. Sometimes reading the directions actually helps.

 

The humidity is killer just about anywhere in the USA what with all the rain lately. And any condensation due to variable weather just compounds the issue.
I have read that Gibbs Brand is a good treatment to neutralize and protect from rust for a while, and it claims that it can be painted over and not have to be removed, washed, etc.
I use Gibbs Brand to help prevent rust, oxidation, etc, but I have not personally painted over it so you need to check into this yourself and take my suggestion with a grain of salt and a question mark.

 

Ford had a lt. Blue paint, used on '66-68 cars that had what appeared to be a phosphoric treatment beneath, IIRC. Often the paint peeled up, revealing the phospho beneath.

 

And I don't believe Por-15 likes sun(uv).

 

If you are worried about a rust treatment under the primer I would get in contact with the primer manufacturer. I used Sherwin Williams products for my OT restoration and used the recommended Met-L-Etch before the NP75 primer. Otherwise knock it down to bare metal and epoxy prime same day.

 

I know it's too late, but never mix products from different paint companies. Some just don't play well with each other. Any time I paint something, I always use the same brand product from start to finish.

 

Yep, and I've lived by that, I totally believed the Paint Supply store owner....bad idea but you know what they say about hindsight
Now I have to worry about what can go over the sanded phosphate coating and yet still seal rust.
Aside from wise answers, does anyone have any experience with this?

 

Pinstriper40 told you the best procedure sand it all off and epoxy.

 

80 grit seems a little excessive, doesn’t it?

 

Yes! Unless you are going to go through the grits 80 grit (boulder paper) is too course.

Pat

 

80 grit with a da is perfect. Prime with epoxy primer and forget about it. Lots of info on the web. I always thought por was good for old rusty jeep frames or crusty trailers. Not for "A" surfaces.

 

No it is what most Epoxy primers will recommend spraying over for bare metal. However, ALWAYS read the product information sheets for the product you are using it will let you know what is required. You have already learned the hard way what taking advice from people can get you when dealing with specific products.

 

Just to clarify...I applied POR-15’s Metal Prep....did not apply POR-15 paint and never had intention to. I only wanted to treat the bare metal with an acid phosphate to stop the rust before priming and paint.

 

I often use ospho as one step in surface prep, but "Days after I finished rinsing the Metal Prep, I noticed a golden tint over most of the car" is concerning. It's one of the last steps before actually putting down primer for just this reason.

 

I quit using POR products for several reasons. Number one was what you experienced. Number two was that NOTHING will adhere to POR. Number three was it is not tolerant of UV. Number four was I dont Paint Over Rust. There are more but this is not a product I care to use on my hard work. YMMV. If so, knock yourself out.

 

Title of this thread is misleading, should be got screwed by my paint supplier. I use a product called Rusticide on bare metal before primer, has worked great for the last 25-30 years. As stated above I would strip with 80 grit and start out fresh.

 

About 10 years ago I purchased a quart of POR Gloss Black and believe it or not I couldn't get the top of the can off. I literally had to puncture the can and drain it into a quart container. The jerk I talked to said "they must have spilled some on the lip of the can when they filled it". So basically tough s**t.

 

You washed the car down with water and left it for days.
Come on man, what did you expect? Not POR15's fault. I would have a hard time blaming the paint rep too for that matter.

 

Yup, after I open a can I put some plastic sheeting over the can then put the cover on. If you don't, you may not get it open again!

 

80 grit DA is the preferred method with epoxy. Especially if you plan to do body work over it.

 

The old method with using epoxy was using a conversion coating (metal wash) product first. Most all have stopped this
Always look up the tech sheet on every product you use. They are easy to do find just by googling the product name and number. It tells you everything ya need to know from surface prep to mixing instructions.
Never trust the salesman alone.

 

I hit salesmen with hammers

 

80g is what helps the primer adhere to the body. Ever see cars with flaky paint? It's from dingbats who dont know what grit to use between the paint and primer or who are just too lazy to prep it right.
Don't be a dingbat. Paint is expensive, the process is labor intensive. When done right the first time, a modern paint job should last 30 years on a restoration. This is assuming it is kept inside and properly maintained. I dont know about you guys, but i hate having to do stuff twice.

 

The gold color was flash rust. A bluish/ grayish color is what you want after rinsing and drying.
To deal with and prevent it work one panel at a time.
Rinse the product off with plenty of clean water and a clean cloth or scotchbrite. If the product has dried I usually rewet it and then rinse.
Drying the rinsed panel to bone dry quickly is very important. I mop off the bulk of the water with a clean absorbent cloth or squeegee then immediately blow it to bone dry with compressed air.
Even then some gold might appear and you can wipe over it with a water dampened clean cloth and fully dry it again.
Doesn't hurt to use clean mop rags for each panel to avoid contaminating the the next panel.

 

just to clear up the confusion, 80 grit DA would be too coarse for a "soft" surface like filler, primer or paint. 80 grit DA is perfect for sheet metal. the harder the surface, the coarser the paper it takes to "break" the surface. when i refinish old cast iron sinks or claw foot bath tubs i DA with 24 grit, yes twenty four, then epoxy prime and urethane paint for a glossy finish that looks like porcelain.

 

That acid phosphate coating may not be comparable with some epoxy primers. Some epixyies are more tolerant rhan others that seems like the metal spit the epoxy off like a watermelon seed.