Cleaning Metal Frame for Primer Painting

I have a old Athearn RDC dummy that I picked up at a swap,meet that I want to paint and freshen up. Is there a preferred method of cleaning the metal frame prior to primer painting it, or is soap and water sufficient? Cedarwoodron

I always give metal parts a wash down in laquer thinners. Guaranteed to get rid of any oils or greases left behind. If the metal chassis is already been factory painted, a wash with alcohol will do the same thing but not soften the factory paint.

Mark.

I’ve had good luck using Zep Degreaser. It’s a citrus-based product available at Home Depot. It takes off the oils and grease and doesn’t hurt the paint. I follow it with a wash with Dawn and the parts come out “squeaky clean”.

Joe

Let’s check here. It’s a Zamac frame and it’s bare metal? never been painted? And you are gonna give it a coat of auto primer from a rattle can?

In that case, there are two steps in surface prep. Step one is degreasing it. Step 2 is etching the metal to give some tooth for the primer to grab onto.

Degreasing can be hot soapy water, followed by a water rinse. Your choice of soap. Laundry detergent is more active than dish wash liquid, but both work. Or you can use a solvent, alcohol, mineral spirits, acetone, or lacquer thinner. Wipe it on with a rag. Use enough to get all the grease. You gotta do some rubbing. If you just slop on some solvent, it will dissolve the grease all right but then the solvent evaporates and the grease stays behind, and you haven’t accomplished much. Be careful with acetone and lacquer thinner, spills can dissolve floor tile, paint, plastic, plastic drain pipe, lots of stuff. Was it me, I’d stick with alcohol. Or hot soapy water.

Etching, or pickling is done by soaking the metal in a mild acid. I use supermarket vinegar cause I have some. Don’t use the strong mineral acids like battery acid or nitric acid, they are too strong. An hour or two is enough. Rinse well in water to get the acid off before painting. Dry well.

If the frame is areadly painted, and you arn’t going to remove the paint, then skip the etching step. Paint doesn’t etch in acid.

I have a bare metal frame- didn’t even give a thought to etching the metal! Vinegar it is! cedarwoodron