Question regarding painting Brass Diesels

[ctulanko]

I have collected some data off this website and others, but there are a few details I am missing with regards to painting brass, as it is something I have not done. I have used an airbrush many times in the past and feel I can do a good job of it; thanks must go to wombat457 for his compressor thread, which inspired me to upgrade my airbrush equipment!


So far I have done the following:

Chose a lesser quality Diesel to experiment with
Disassembled it down to the brass components that require paint
Built a stand to hold each component during the painting process
Soaked the brass parts in Lacquer Thinner overnight
Used gloves from this point on
Brushed the components with a toothbrush in the bath to clean them off
Washed the components in a light detergent warm water bath, then thoroughly rinsed them off in warm to hot water
Used a hand dryer to dry off each part

Now for the tricky part...I have vinegar to use for etching the brass. I have seen some people say to use full strength for 90 seconds - two minutes, others are cutting it with water and leaving it overnight. What is the ratio and which method is preferred? Use distilled water if cutting it?

I do plan on doing a bath in warm water with baking soda after the etching, as well as a thorough rinse after the bath with either warm, or I prefer hotter water, as it helps with drying.
Next, I would dry the parts with a dryer once again
I then plan on using a Testors metalizer primer, as recommended by our local hobby shop MRR employees. ( is sanding required? Will it be too thick and cover the details? I plan on using a light coat or so)
I have the correct color, Pennsylvania Brunswick Green paint from Polyscale; I purchased the last two bottles the had in stock.
A Badger electric paint mixer (I was told not to shake the bottle due to air bubbles) will be used to thin the paint to a 2% milk consistency ( thanks Espeefan for the tip) using acrylic thinner. I was told to mix it well before thinning, as the color has somewhat settled to the bottom

So, besides spraying the finish, did I miss anything? I am new to painting brass and I want to make sure I am doing it right the first time.

As always, any and all help is appreciated.

Thanks,

Carl

 

[Mark R.]

I've heard of the vinegar soak, but have never tried it. Have never heard of the baking soda soak (?) - what's that supposed to do ?

Myself, and I've painted a LOT of brass over the years, is, once the original finish is stripped and I'm down to bare brass, I give it a good scrub in some hot water with a toothbrush and some powdered cleanser made for cleaning brass / copper. After a good rinse, I let it dry - with the assistance of a hair dryer if I need to keep moving.

For primer, I always use Tamiya Fine Surface Primer in the rattle can. It's expensive compared to anything else, but is the best I've found for adhesion on bare brass. Before discovering this primer, I used to media blast all the parts with baking soda to improve adhesion, but I find I don't have to do that any more with this primer.

Mark.

 

[ctulanko]

The baking soda added to a water creates an alkaline bath that should counteract/help neutralize the acid from the vinegar bath. I think it is another safety step to insure the model is clean of all corrosive chemicals(acid in vinegar) and I believe a good water rinse should follow. I know of the brand Tamiya, as I have used their paints on polycarb bodies before, but I didn't know their primers would work on brass...thanks for the tip!

I take it you don't sand your primer, but rather use it as a light coat to promote better paint adhesion?

I would still like to know more about the vinegar bath as well, so anyone please step right in and let me know. I learned a long time ago a good bit of research helps, so I always give that a try before asking foolish questions! Alas, I still have to ask, so the floor is open.