Painting stainless steel etched car sides

[jmlaboda]

I am about to start assembling a collection of Business Car sides that have been etched from stainless steel and was wondering if anyone could recommend a proper paint for metal sides that will adhere to the stainless steel.  I have wanted something like this for a very long time and now that I have several sets in hand I want to be sure to properly take steps to do these sides right once I am ready to paint them so that assembly will go well as well.  Any ideas on the type of paint and how to deal with the sides would be greatly appreciated!!!

[peteski]

Since some parts of the car will be plastic and others metal I recommend a coat of primer before shooting the final color.

In my arsenal of paints I have a can of  self-etching primer . If you follow that link the info will show you that this primer adheres very well to stainless steel.  After that you should be able to use any of the hobby paints for the final color.

[John]

automotive primer?

[sd45elect2000]

I also used self etching primer as peteski suggested. In addition I sanded the raw stainless before priming it to remove some oxides. Use low tack tape for masking .

Randy

[Scott Lupia]

Jerry, I don't use primer or anything else. Polly Scale acrylic will stick to the stainless without issue. Just clean the sides thoroughly before painting.  My paint jobs required masking for the window band and the Tamiya masking tape didn't peel the first layer of paint. That was good news for me!  Since the body is mostly a half etch, the sides have some tooth to them so the paint seems to really like that. I like to keep the paint thickness down to a minimum so it doesn't hide detail. Give it a shot!  Can't wait to see what those sides look like!

Scott Lupia

[up1950s]

Well being that you are going to apply paint why not give it some tooth with 600 sandpaper .

[jmlaboda]

Thanks for all the ideas... I do appreciate them all.  Not sure what paint I will be using yet (have to go to Salisbury, N.C. to the VA Hospital Dec. 7th so I will be going by Spencer to check what paints the Little Choo Choo Shop has in stock) but once I go I will have a better plan of attack for painting the parts.

Well being that you are going to apply paint why not give it some tooth with 600 sandpaper .

Actually I have some 1000 Wetordry I am going to use to polish the parts but am concerned about the rivet detail.  While I doubt it will hurt the detail I am concerned about how easy it will be to polish around the rivet detail but hopefully before the weekend I will have some idea about that as well.

[peteski]

While I doubt it will hurt the detail I am concerned about how easy it will be to polish around the rivet detail but hopefully before the weekend I will have some idea about that as well.

Sounds like the area around rivets is half-etched metal. Not need to polish it - the satin-finish etched surface is perfect for maximizing paint or primer adhesion. You actually don't want to polish anything.   If you were to truly polish metal surface to a mirror finish that would actually make it harder for the paint to adhere to.

But 1000 grit paper doesn't really polish anything - it is too coarse for that.  But that is ok - if you want to roughen the metal surfaces with 1000 grit paper that will be ok for paint adhesion.

[havingfuntoo]

Warm Phosphoric Acid at 25% is used to prepare stainless for painting, use a hydrocarbon solvent to remove any contamination prior to using the phosphoric acid.
Don't leave it in the phosphoric acid mixture too long as it can be quiet aggressive on some grades of stainless. When etching is complete simply rinse off with fresh water, dry and paint.

[craigolio1]

Where would I find phosphoric acid?

[peteski]

Where would I find phosphoric acid?

Coca-Cola!    Seriously. http://blog.fooducate.com/2009/06/30/11-quick-facts-about-phosphoric-acid-yes-that-chemical-in-coca-cola/

Honestly, I think that phosphoric acid will be a bit of an overkill. Etching primer (as the name implies) shouldn't need any additional surface etching of the metal.  And the half-etched surfaces of the car sides are already pre-etched by . . . the photoetching process itself.

[nkalanaga]

If you use Coca-Cola, or other carbonated beverage, it might be a good idea to use a diet beverage.  Rinsing thoroughly should remove it, but any sugar that stays can get very sticky.  The artificial sweeteners come off more easily.

We had that problem with our keypunch machines in  the late 70s.  If the keypunch operator spilled coffee or diet drinks in the keys, no problem.  But if the drink had sugar, or cream in the coffee, it was almost impossible to get the switches under the keys clean again.  Most modern keyboards use pressure-sensitive keys, rather than mechanical switches, so that's less of a problem.

[havingfuntoo]

Most industrial chemical supplies will have it in their range, some times they will combine it with a surfactant to slow down the attack on the base metal, auto paint shop suppliers should also be able to help. It is used in the preparation of a lot of commercial foods also. Etch primers do contain it in their formulations but they are often a coarse grind, which results in a loss of detail.

Coca cola is not where I would be looking.

Another way of preparing a metal model for paint is to take some molasses mix it with water and boil it up. After it has cooled place the items in the brew for a short period of time (15 min) then check it, keep to your 15 minute cycle until you get the desired finish. This brew will clean the oil off it and give the item a very fine etch, again depending on the grade of Stainless Steel. Your starting point should be to establish what grade of Stainless you have.   

[Mike C]

Where would I find phosphoric acid?

  Homer Depot or Lowes should have it .