Quick primer/metal prep question

[barronj]

In the process of stripping the myriad colors off my doors & staging everything for primer/paint, is it necessary to do anything to the exposed metal after I've sanded it down, before it gets primered professionaly?

My gut tells me to hit it up w/ rattle can primer in the interim, then knock that off before it gets primered "for real".

 

[Explorer]

That'll work, but use rattle primer sealer or just any reg color of your choice. Straight primer will draw moisture. Before I get flamed, only reason I'm saying it's ok, is you're going to sand it off.

 

[needabronco]

Your just creating an extra step and extra work. Bare metal is fine as long as you don't get it wet, even then just make sure it's completely dry, hit it with some wax/grease remover and spray it with a good catalyzed primer (not rattle can) that is a metal etching primer, and your good to go.

 

[byson1]

Really depends on how long it's going to be "bare" and where you live. It does not take long for flash rust to develop in TN with our super high humidity levels.

 

[barronj]

Austin. Humidity comes & goes, but 100 degrees is on tap daily.

 

[TN1776]

I would not bother with the rattlecan stuff, as others have said you're just creating an extra step. I live in a pretty dry climate in Northern CA and parts of my sheet metal were bare for 6 months, and I only had very minor surface rust develop. I've discovered that phosphoric acid (in any number of retail rust converter brands) works wonders on surface rust - turns the stuff into black iron phosphate which is more stable than bare metal, and can be primed over. It's a good pre-primer step.

 

[allenfahey]

I would do as TN1776 said and use phosphoric acid on the bare metal. Should be fine for a few months. You can use an epoxy primer or etch primer followed by a 2k high build primer.

How are you stripping the paint? Are you using stripper? If so a tip on using it is to use some 40 grit and go over the panel just to scratch it up a bit. Then use the stripper, the stripper will penetrate the surface quicker and will require less coats of stripper if you have many layers of paint. Final sanding on the filler and bare metal should be in 180 prior to primer.

 

[barronj]

I would do as TN1776 said and use phosphoric acid on the bare metal. Should be fine for a few months. You can use an epoxy primer or etch primer followed by a 2k high build primer.

How are you stripping the paint? Are you using stripper? If so a tip on using it is to use some 40 grit and go over the panel just to scratch it up a bit. Then use the stripper, the stripper will penetrate the surface quicker and will require less coats of stripper if you have many layers of paint. Final sanding on the filler and bare metal should be in 180 prior to primer.

Wire cup/brush on an angle grinder (eats the paint off pretty well), then smoothing with 120 on DA.

I'm open to all suggestions though!