painting/blackening brass locomotives.

[electrical whiz kid]

As per Jonathan's suggestion, I am starting a new topic
As of late, I had purchased a number of brass locomotives.  Naturally, they are all steam...
I would like to invite EVERYONE, regardless of  expertise, to get into this topic.
My thought is-first off-to discuss the thought of just cleaning down to the brass (via sonic, solvent/remover, etc.), the methods used here, and the thoughts on paint-type, colour, etc.  I have several mediums as far as paint.   I am not prone to use acrylic on brass-but that is only my thought.  I have several bottles of Floquil laquer rolling around on a mixer I built (works like gangbusters!!) .  I installed a 1/4-20 nut in each bottle-any fairly large nut will do-as an agitator, so they are ready and able.
As well as steam, diesel would go through basically the same process for a quality job.
The second thought is-again- cleaning them right down to the skin; but instead of paint, I want to first blacken them.  I have had very good luck with a product called "Blacken It" for this process for various other parts.  That done, them prime and paint accordingly.  my thought is that the blackening process will produce a "natural" look that might be found on a locomotive too busy to visit "ye olde paint shoppe."
As I said:  Your thoughts, each one of you.

Rich C.

And as I said, this is open to any level; we-all of us-neither know everything, or have perfect equipment.  There are no Gods here, so all are invited to participate

[jonathan]

OK, I'll start. However, I am no expert, but these methods have worked for me.

You have a choice right off the bat:  Leave the factory lacquer on and paint over it. Or, strip off the lacquer and paint onto the bare brass.  I have done both.  Personally, I find it depends upon how thick the lacquer.  If the lacquer is thin enough as to not cover rivet detail, I paint on top of the lacquer.  The paint adheres better, and the whole process is a bit quicker:

Choice #1: scrub with hot soapy water, rinse and rinse and rinse.  Let dry while on your paint stand, at least overnight, but 24 hours is the norm.

Choice #2: Strip the lacquer because it's chipped, scratched or too thick.  I boil the brass parts in an old pot of water with two tablespoons of baking soda, for 30 minutes. I find you will have to do this twice to get all the lacquer off.  Then "pickle" the brass parts in white vinegar... oh say overnight, just to make sure the parts are really etched and can hold paint.  Then, follow on with choice #1 above.

My favorite primer is Floquil Grimy Black.  Doesn't exist anymore.  If you have some, use it.  It goes on super thin and covers well.  Your top coats will stick to it well.  I have started using Rustoleum Ultra Cover 2X Primer--readily available at the major hardware stores, it's a nice dark gray, goes on fairly thin, and it bonds to most materials.

When the primer is dry (24-48 hours) Bake your parts in a 170F degree oven for 20 to 30 minutes.  I put the parts in the oven cold, start the oven, let the parts bake for 20 minutes after oven reached temp, then leave the parts in while the oven cools.  I do this with every coat.

I use to paint brass with gloss coats, you know, for the decals.  Now I use flat paints because they go on thinner.  The gloss coat gets sprayed in prep for the decals.

Keep in mind, I have neither the space, desire, nor the funds to start an airbrush operation in my home.  BUT, I do believe the airbrush would bring superior results.

OK I've rambled long enough.

I'll share this one photo to show you my paint stand.  It's simply a 1"X3" board, a piece cut out of the top, and a screw.  This holds locomotive shells, and many other parts, very well:


Oh, I almost forgot... I have tried Blacken It, with terrible results.  You must know the trick with that stuff.  I never could get it to produce a finish I liked.  Also it doesn't seem to be permanent.

I have gotten braver with weathering, using browns, grays and a "mud" color, another Floquil product that no longer exists.


Regards,

Jonathan

[AGSB]

Issue #8 (July/August 2010) of Model Railroad Hobbyist, on page 36 has a short article on painting brass. This magazine is free and available online.

[Woody Elmore]

Floquil used to market a red zinc primer which I used with good results. I believe that Scalecoat still has their laquers avaialblae.

[ebtnut]

I concur with Jonathon re:  the factory lacquer.  If it's nice and thin and even, keep it.  Otherwise, strip it off.  The model has to be disassembled for best results.  Wash all the parts that will be painted with a good detergent using an old toothbrush to scrub well.  Rinse very well and let dry.  I'm still a believer in using Scalecoat paints. Try not to touch the clean brass with your bare hands, as the skin oil can leave a spot that will show up later.  Hit everything with a primer and let dry well, at least overnight.  Then use your colors.  An airbrush is the best applicator.  You need to thin the paints to about the consistency of 2% milk and make multiple even passes to apply the color.  You want the paint to go on "wet" but not so heavy that it tries to run.    Practice on some scrap material to get the feel. If you use acrylics, the finish is usually flat, so you'll need to spray on some gloss for decaling, then hit it again with Dullcoat or other flat finish.  Weathering is at your own choosing, but don't overdo it.   

[electrical whiz kid]

Just bought  an old brass piece.  A DM&IR 2-8-2.  Got my work cut out for me.   It is an engine I had always wanted, so I had bought it.  In fact, the Bachmann 2-10-2s I detailed, I had put the air reservoirs on the top of the boiler, as ere on the Duluth Mike.  It is kind of "tarnished", but shouldn't be too bad to take care of.
Rich C.

[ebtnut]

Tarnish is not an issue if you are going to paint the loco. 

[electrical whiz kid]

EBNUT:
OK;  Given tarnish isn't an issue...  Tarnish is a product of air/moisture in contact with-in this case-brass.   I am no expert, but I think you are wrong.  I know it doesn't have to be shiny "can see myself" clean, but I won't leave anything on that body that might, in the future, louse up all of my work.  Standard paint prep on any metal surface mandates that it be clean, dry and free of unwanted agents.  I don't know about you sir, but that's the horse I'm betting on.  That Mike is full of tarnish and oxidation, and you can bet your socks it will be clean and dry before any paint is applied.
Rich C.