Primer Question (Allen?)

[pbets756]

I used to paint but have been out of it for over 10 years. I used to use acid etching primer on bare metal and would build up using the old laquer primers. I have been media blasting parts and areas on my new Bronco and am getting ready to shoot some primer. What are the best primers out there now for bare metal and whats best for build up before paint? I will be using B/C paint. This will eventually be a body off frame restoration but for now I am rebuilding areas on the frame yet for stability. thanks Paul

 

[allenfahey]

I used to paint but have been out of it for over 10 years. I used to use acid etching primer on bare metal and would build up using the old laquer primers. I have been media blasting parts and areas on my new Bronco and am getting ready to shoot some primer. What are the best primers out there now for bare metal and whats best for build up before paint? I will be using B/C paint. This will eventually be a body off frame restoration but for now I am rebuilding areas on the frame yet for stability. thanks Paul

Finish all sanding whether it's body filler or the metal in no coarser than 180. You can either use an epoxy primer which is a DTM (direct to metal) primer. You can also use an etch primer but only apply it to the bare metal and after it flashes apply a 2K High Build or HS (high solids) primer. Don't spray epoxy over top of etching. Usually epoxy primers are harder to sand compared to a high build 2K. I like using HS primers because they sand better.

I don't know where you live but if you can, stay away from all low VOC primers. In my area we have had to switch to low VOC products including waterbourne paint. The paint is great but the primers are hard to sand.

 

[pbets756]

Thank you Allen for the great info. Im in Iowa and not affected by the low VOC paints yet but im sure its coming. Paul

 

[00gyrhed]

allen

what happens if you do spray epoxy primer over etching?

curious because I have some issues and I did spray epoxy primer over acid etched metal.

didnt know there was a problem wonder if its causing mine?

 

[bknbronco]

I took allens advise 2 years ago and went with a epoxy primer (PPG in my case). It was a good choice for me because it did the job of 3 different paint products. 1-bare metal primer, 2-good bond to old unknown types of paint, and 3-used as a sealer coat before color top coats. Also has a longer window before it needs topcoat which was perfect for me because I split up my painting over a few days so I could also seam seal some stuff. I believe my PPG epoxy primer had a few day window if not up to a week???? If I had to buy all 3 different products and associated reducers, hardners, etc it would have broke the bank. Its always nice to have epoxy primer laying around for other projects from axles and frames, to smaller items like steering boxes and such.

If I had to pick a build up primer I would just head to my local paint store and grab there high build PPG primer and associated reducers and hardners.

 

[allenfahey]

allen

what happens if you do spray epoxy primer over etching?

curious because I have some issues and I did spray epoxy primer over acid etched metal.

didnt know there was a problem wonder if its causing mine?

I have no idea why. I've attended Standox, Spies, PPG, and Sherwin-Williams painter certification classes alon with ICAR Platinum classes. When they would go over the sections on primer all of them said never to apply epoxy over top etching. I guess the epoxy reacts to the etching and can possibly lift??? ALWAYS read the TDS (technical data sheet) and it will tell you what the substrates you can apply along with mix ratios, dry times, what products to use in it, ect. If you do a Google search for XXX primer and add TDS you should get a PDF of the TDS.

 

[RubberTramp]

I have no idea why. I've attended Standox, Spies, PPG, and Sherwin-Williams painter certification classes alon with ICAR Platinum classes. When they would go over the sections on primer all of them said never to apply epoxy over top etching. I guess the epoxy reacts to the etching and can possibly lift??? ALWAYS read the TDS (technical data sheet) and it will tell you what the substrates you can apply along with mix ratios, dry times, what products to use in it, ect. If you do a Google search for XXX primer and add TDS you should get a PDF of the TDS.

Im pretty sure thats why they say not because of adhesion problems, Ive seen people spray it over top of dupont etching primer and it not lift but if it did that would be a waste of materials and alot of time prepping all over again !