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A few questions about Painting Brass

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  • Member since
    June 2022
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A few questions about Painting Brass
Posted by LebryantJohnson on Sunday, July 2, 2023 2:56 AM

I know this question has been asked many times over the years. I've read all the threads and I'm still a little bit confused on the process.

 

I have a PFM brass steam engine that I wish to paint. I have lacquer thinner, white vinegar, and etching auto primer. As far as I understand I soak the engine and the tender in the laquer thinner and then use a tooth brush after to completely strip it. What I am confused about is what has to be taken out to strip? The motor? The wheels? The tender wheels? 

 

The next step as I understand is to wash the model with soap and water. After that I am to soak in vinegar. Once again the same questions. What am I allowed to soak in vinegar? I'd imagine the motor would have to come out but what else does? For how long do I soak the model?

 

Ok now I wash again after soaking.

Priming and paintin the boiler and tender doesn't seem complicated. The frame is where it gets interesting though. However, all the previous threads mention paints that I don't believe are available anymore. What should I use? I just need black it is an ATSF engine.  I've gotten a lot better at working with engines and taking them apart. However I can not take wheels, valve gear, and the rest of the mechanism apart because I know I can't get it back together. Is it ok if I prime and airbrush with the driver's moving under motor power and then use lacquer to get it off of the places I don't want it? 

I'm not expecting muesuem quality or anything. Just something decent I can be proud of.

  • Member since
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Posted by BigDaddy on Wednesday, July 5, 2023 4:25 PM

Your post was probably delayed because of moderation.  I'm giving it a bump so the Brass Congnicenti can give you an answer. 

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by wrench567 on Wednesday, July 5, 2023 5:49 PM

  Most brass is already covered in a clear laquer. If the clear is clean, no runs, dust, and even then a stripper is not necessary. Wash the boiler and tender shell in hot soapy water and air dry. The clear laquer is the primer. Test the paint in a conspicuous area to see if it's compatible with the laquer. The running gear and frame along with the tender trucks can be painted with a brush or sprayed if you're comfortable doing it.

   Be careful of automotive primers. Some are filling and conseal small details. If you have to strip the clear, then the job becomes more difficult. Clean brass will tarnish quickly so after rinsing the stripper off. Put it immediately in the pickling solution.

    Hope this helps.

        Pete.

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Posted by SeeYou190 on Wednesday, July 5, 2023 10:44 PM

I am just going to throw this out there...

I think all the rules about painting brass models with exotic or complicated techniques are a bunch of hooey. These probably date to a time when brass was uncoated and tarnished easily. Now they have become beloved legends from an ancient time.

I have painted many brass freight cars and cabooses, and a couple of locomotives. I have NEVER had paint come off a brass train car.

My first was a Tenshodo 0-8-0 that I painted with automotive primer and Testors spray black. 20 years later, and all the paint is still on it.

When I paint brass, I clean it with autmotive brake cleaner, dry it with compressed air, soak in vinegar, rinse with water, dry with compressed air, and prime.

Nothing more special than that, and it is probably a bit much.

-Photograph by Kevin Parson

You will need to remove the motor if you are going to paint the frame. I am just going to brush paint the frame on my future locomotives for ease. You can barely see it anyway.

-Kevin

Living the dream.

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Posted by snjroy on Friday, July 7, 2023 7:28 AM

I agree, don't take the drive mechanism apart if it runs well as is. Remove the boiler and clean all components carefully to remove oils and grime. Is there tarnish on the boiler? A small amount of tarnish can be carefully removed with a dremel and a wires brush. Heavy tarnish can be removed with a hobby blaster, using soda as a medium.

I don't use vinegar, but if you do, don't let it soak too long. It can cause corrosion. 

Most folks use auto primer for the first coat. I apply a coat of dilluted shellac before the primer, which most folks don't do anymore from what I understand. As mentionned by Kevin, if there is no tarnish, chances are that the model is pre-varnished.

The final coat can be done with acrylic or oil-based paints. For the primer coat, I spray the boiler and tender (removed), and bake them for about 20 minutes at 250 degrees while they dry. Baking the model is probably unneccessary if it was pre-varnished.

Finally, I paint brush the wheels and frame. A light coat can be sprayed on the wheels to give them a better finish.

Simon

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Posted by rrebell on Friday, July 7, 2023 8:16 AM

the real problem here is paints have changed and are generaly much better now but always test your paint, had a few times in the 1-1 world and hobby that the paint formula was just wrong, bubbles and non cureing etc.

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Posted by Overmod on Friday, July 7, 2023 9:25 PM

If you pickle, you may want to passivate as well as just rinse -- a little baking soda dissolved in hot water for the first rinse.  Use deionized/distilled water for the final rinse.  [This of course presumes that you have stripped the old clearcoat, finish, and tarnish off the parts of the model to be painted, which may or may not be 'necessary' depending on your taste or desires.]  Be VERY alert to the condition of the solder joints -- if they are whitish or green, be very careful not to start dislodging details...

Self-etching primer always seemed to me like a good idea, especially if you thin it to avoid hiding detail.  As noted you really don't need it to make sure paint sticks to the model, but i think it helps to prepare the surface with a clean continuous 'undercoat'.

Be careful with that baking in the oven.  Many of these locomotives have dodgy solder joints that you don't want to start compromising...

Whatever you do, don't paint the engine 'black'.  There are many good discussions here about what is essentially a trompe l'oeil method of reproducing the effect of skylight and shadow on a real locomotive, plus the effects of weathering and dust.  At the very least, start with grays.

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Posted by SeeYou190 on Friday, July 7, 2023 10:39 PM

snjroy
I don't use vinegar, but if you do, don't let it soak too long. It can cause corrosion.

Since nearly all brass models are clear coated at the factory, I really do not think the vinegar does anything at all.

Still, it is in my routine, and I will continue to do it.

-Kevin

Living the dream.

  • Member since
    October 2022
  • From: Pasadena California
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Posted by BradenD on Sunday, July 9, 2023 2:57 PM

When did they start clear coating at the factory?

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Posted by wrench567 on Sunday, July 9, 2023 10:55 PM

BradenD

When did they start clear coating at the factory?

 

  Many decades ago. Clear shellac in the early years. Around the seventies they started doing clear laquer. Some brass is even painted brass and then clear. The boiler on my Westside K5s was painted brass but the tender wasn't.

My MB Austin 2-6-0 had a thick coat of shellac with runs, dust and dirt embedded in it. It was imported in 1957.

  I'm done with painting brass. I buy nothing but factory painted now. I hung up the air brush after doing my K5s.

      Pete.

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  • From: Southern Florida Gulf Coast
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Posted by SeeYou190 on Sunday, July 9, 2023 11:16 PM

BradenD
When did they start clear coating at the factory?

A long time ago...

I think this is my oldest brass model, a PFM/United 2-8-0 imported in 1971.

-Photograph by Kevin Parson

It absolutely has a clear coat on it.

-Kevin

Living the dream.

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