Brass car side prep

[Ike the BN Freak]

I got a few Brass car sides that I'd like to prep for primer.

Trying to read up on it where I can, seeing lots of different methods. Trying to find something easy/quick. I know many recommend "baking" each coat, however can you just prime then bake, and not bake final colors?

[Iain]

Clean real well, first soap, then alcohol, and finally dip in plain white vinegar for a few minutes to etch the surface just a bit, rinse with clean water, let dry.

Prime and then bake will work, but not quite as well as prime, bake, paint, bake.

[peteski]

Baking is also not mandatory.  Sure, it will harden the paint, but even without that the paint will stick well enough.

Case in point: many years ago I made some corrugated Amtrak baggage cars using etched sides and Con-Cor cars as the core.  I glued the cleaned brass sides to the plastic car (IIRC I used 5-minute epoxy), then I painted the entire car using Accu Paint primer then Accu Paint Aluminum.  After the paint was dry I masked and painted the stripes (again using Accu Paints).  That car was ran many times on NTRAK layouts and I had no problems with paint coming off the brass.

[robert3985]

I've done several brass car side kitbashes, and never have "etched" them with vinegar.  I make sure they're totally degreased by first washing them in soap (Dawn) and warm water before I assemble, then when the side is ready to paint, I degrease with fresh Bestine.

I also don't use a primer, but use Scalecoat II, which states that it doesn't need a primer...which in my experience, is true.

If I paint the sides before gluing them to the plastic car shell, I'll bake them for 20 minutes in a preheated oven with an in-oven thermometer visible...at 165 degrees.

If I paint the whole car, I let it sit for a couple of days between colors...until them smell goes away.

If I use acrylic paint (which I am doing more frequently) I just heat up both plastic and metal with a hairdryer for a few minutes..."high" for metal only, and "medium" for plastic or metal/plastic but for longer.

I don't get any chipping at all on any of my brass car side projects, or on my other 100% brass models.

I am careful to use the correct air pressure in my airbrush so I don't get "orange-peel" or a pebbly surface from having the paint go on dry.  I also have a moisture trap on my regulator AND a Paasche in-line moisture trap on each of my airbrush hoses to make sure there's no moisture coming out the airbrush.  I also regularly drain the air tank on my compressor to get rid of accumulated water in it.

Lastly, I don't shake my paints any longer, but I stir them using a Badger battery powered stirrer/mixer, which does a fabulous job of minimizing chunks and thick paint for smoother end results.

Cheerio!
Bob Gilmore

[OldEastRR]

Here's an older thread on this subject

https://www.therailwire.net/forum/index.php?topic=34430.0

[thomasjmdavis]

All the advice in this thread and the older one referenced is very helpful, but leaves me with a question:

Many sides are coated with a clear coat (sometimes referred to as Krylon, but there are a couple versions even of that).  Do the various cleaning procedures advocated (Bestine, MEK, alcohol, acetone) attack or remove that coating?  In the past, I have left it alone (sticking to dishsoap and alcohol for cleaning), but I am beginning a new project (L&N rebuilt coaches from Brass Car Sides) and want to get the best finish I can.  I favor water based acrylic paints because they are safer in a closed house in the winter.  Recommendations?

Many thanks, especially to Bob Gilmore for that thorough tutorial.

I also have some older sides that are tarnished (I picked some BCS sidesup via auction and they had apparently been stripped of the clear coat but never painted, others are just 30 years old, from old wood/brass kits).  Can I prep the surface to take paint?  Steel wool on the kits doesn't seem a good idea, because there is a fair amount of etched detail.

[peteski]

All the advice in this thread and the older one referenced is very helpful, but leaves me with a question:

Many sides are coated with a clear coat (sometimes referred to as Krylon, but there are a couple versions even of that).  Do the various cleaning procedures advocated (Bestine, MEK, alcohol, acetone) attack or remove that coating?  In the past, I have left it alone (sticking to dishsoap and alcohol for cleaning), but I am beginning a new project (L&N rebuilt coaches from Brass Car Sides) and want to get the best finish I can.  I favor water based acrylic paints because they are safer in a closed house in the winter.  Recommendations?

Many thanks, especially to Bob Gilmore for that thorough tutorial.

I also have some older sides that are tarnished (I picked some BCS sidesup via auction and they had apparently been stripped of the clear coat but never painted, others are just 30 years old, from old wood/brass kits).  Can I prep the surface to take paint?  Steel wool on the kits doesn't seem a good idea, because there is a fair amount of etched detail.

Many older unpainted brass engines had a clear coat over the bare brass (so they didn't tarnish).  Krylon is just a brand name (like Kleenex) for any type of clear lacquer (or enamel).  Unless it is a very heavy coat I don't think it needs to be removed. It will act like a primer.

But I never seen car sides (or any brass parts designed to be utilized in making a model) being clear-coated.  Maybe some parts still have the photoresist left on the unetched portions of the parts.  But all the etched areas should be bare brass.  The photoresist can and should be removed. I usually use acetone, but lacquer thinner should also do the job (as most contain acetone anyway).

As far as tarnish goes, I use a household copper cleaning powder and a toothbrush.  I sprinkle the powder on the part, sprinkle some water and then scrub them with a toothbrush. That turns the powder into a paste and the toothbrush does a good job of getting it in all the crevices.  Then give it a very good rinse with warm water.

I use old worn toothbrushes as the bristles seem to be softer and have pointier ends on the bristles.  I also cut off the handles on some of them and even glue a piece of styrene on top as a handle, turning them into miniature hand-brushes.

[nickelplate759]

Brass Car Sides says they use a Krylon clearcoat in their instruction sheet.

[peteski]

Brass Car Sides says they use a Krylon clearcoat in their instruction sheet.

I guess it's been a while since I bough brass car sides. The last ones I used were sold by JnJ and had no coat on them at all.  If there is an instruction sheet, what does the manufacturer recommend to do for finishing?