etching primer vs regular primer?

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I was told by a neighbor of mine's that whenever you're dealing with bare metal that you need to use an etching primer on it before painting. I've got a can of the paint/primer stuff from hdepot and figure that it should be adequate. who's right?
Reply:etching primer onlyThe metal probably still needs to be sanded and certainly needs to be clean. Then you can shoot your color right over the etching primer. You can get etching primer in aerosol cans from the auto parts paint suppliers.
Reply:I've used three types of primers, clean metal and dirty metal primers for steel.  Etching primer is usually used for aluminum and galvanized steel.  If you have an auto paint store nearby they will gladly give you good advice.  Hardware stores not so much.
Reply:It will work. Self etching is mainly used on aluminum, chrome plated parts, plastics, different metals other than plain steel. It saves on prep time. Make sure you have good ventilation if not spraying outside. It has an acid etcher and burns if you breathe in or get in your eyes.  It also works great for areas that are hard to reach during prep work. If your doing auto body work, make sure and spray over bondo or filler, not directly on metal.
Reply:Etching primers have just a tad of phosphoric acid in them is all. It's a choice."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:The etching primers I have also contain zinc.  How much I don't know.I do know that on slightly rustly material, a light sanding, followed by a washdown with navel jelly (put it on with scrubbing pad, let it sit for 1/2hr or so) and then a wash down (again with scotch bright pad) followed by two coats of etching primer (first one more of a misting, second one complete) followed by duplicolor engine paint - and you have something that will be rust free for a long time.We are talking mostly rattle can paints.Automotive paints (professional high dollar stuff) typically tell you how to mix for different weather (temp and humidity) and typically don't recommend below 50 deg or so.(*this is from memory, the new, water based paints might have completely different parameters, I understand they pretty much NEED heat lamps to fully cure).With rattle can paints, during cold weather (say 40 deg), coats have to be lighter and you need to give it more time to dry.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:When I worked at a hot-rod shop, the paint system (all solvent-based) we used specified etch primer, then high-build primer, then topcoats.  Now, my boss was a bit parsimonious, and he never used the etch primer first.  We never had any issues with the high-build primer peeling away from the steel, but that may have been because we sandblasted everything -- my theory is that probably provided a sufficiently-rough surface profile for the high-build to adhere.He claimed that he uses epoxy primer on really high-budget builds, but we never did while I was there (I do use it on personal projects).I know that, if it had been up to me, I would not have skipped ANY steps recommended by the manufacturer... they won't warranty the paint system if you skip anything. Originally Posted by con_fuse9The etching primers I have also contain zinc.  How much I don't know.I do know that on slightly rustly material, a light sanding, followed by a washdown with navel jelly (put it on with scrubbing pad, let it sit for 1/2hr or so) and then a wash down (again with scotch bright pad) followed by two coats of etching primer (first one more of a misting, second one complete) followed by duplicolor engine paint - and you have something that will be rust free for a long time.We are talking mostly rattle can paints.Automotive paints (professional high dollar stuff) typically tell you how to mix for different weather (temp and humidity) and typically don't recommend below 50 deg or so.(*this is from memory, the new, water based paints might have completely different parameters, I understand they pretty much NEED heat lamps to fully cure).With rattle can paints, during cold weather (say 40 deg), coats have to be lighter and you need to give it more time to dry.
Reply:Originally Posted by WorldPowerLabsWhen I worked at a hot-rod shop, the paint system (all solvent-based) we used specified etch primer, then high-build primer, then topcoats.  Now, my boss was a bit parsimonious, and he never used the etch primer first.  We never had any issues with the high-build primer peeling away from the steel, but that may have been because we sandblasted everything -- my theory is that probably provided a sufficiently-rough surface profile for the high-build to adhere.He claimed that he uses epoxy primer on really high-budget builds, but we never did while I was there (I do use it on personal projects).I know that, if it had been up to me, I would not have skipped ANY steps recommended by the manufacturer... they won't warranty the paint system if you skip anything.
Reply:We use etching primer for aluminum and regular primer steel. Never had any issues as long as you clean it with denatured alcohol to get the oils off. Sent from my C811 4G using TapatalkVantage 300 kubota ,miller 304 xmt ,lincoln ln 25 pro , ranger 305 G, plenty of other tools of the trade to make the sparks fly.