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Getting  ready to start this project and been reading all related threads.  Question, it looks like engine is clear coated--what do I use to strip off the clear coat? I see some use a vinegar solution, does that etch the metal before priming? Any information on painting brass is greatly appreciated! Don20200609_171205

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Getting  ready to start this project and been reading all related threads.  Question, it looks like engine is clear coated--what do I use to strip off the clear coat?

Lacquer thinner should take it off; sometimes it seems that clear coat is tenacious.

I see some use a vinegar solution, does that etch the metal before priming?

Very mildly etches it; got to neutralize & clean it off before painting.

Document (with pictures and notes) each step of disassembly for painting.  What may seem very simple now can be extraordinarily difficult once you are looking at a pile of parts and screws with no assembly instructions.  Along the same lines, separate the parts and screws as you disassemble into major sub-assembly labeled containers to help with the first suggestion.

Chuck

I've painted many brass engines over the years. I have read and talked to others about stripping the lacquer finish and most all agreed that stripping is not necessary unless the clear coat is pealing.

If the clear coat is well applied, just give it a good wash and apply a primer undercoat. Let it dry thoroughly, I usually wait at least 24 hours.

I still have the first engine I ever painted back in the 1970's. The paint has yet to peal or chip, even though I ran it a lot.

The one thing about stripping the clear coat, if you don't get it all removed, you will have some issues that could result in pealing.

Ray

I agree - leave the clear coat.  It is probably catalyzed.

I have a PSC Pullman with corrosion under the clear coat. I have tried lacquer thinner, paint remover, MEK, nothing works.  

When I paint bare brass, I give it a very light bead blast at below 35 psi, with the gun at a 45 degree angle.  Blow the beads off, and immediately prime.  Then Scale Coat gloss, baked on for an hour at around 180 degrees.

Right now, I am in the midst of working on a 1980's Sunset USRA PRR 0-6-0. It has a horizontal drive hidden within the frame. The motor faces rearward, hidden completely within the firebox end of the boiler, with a cogged belt to turn the hidden drive shaft.  Its a bit complicated to disassemble, and took notes as I did it so I can get the thing back together again in a few more weeks after its painted and lettered.

It has a thin coat of gold paint on it, that must come off before it gets painted. It also has to be removed to re-solder some parts that broke off or were cold soldered to begin with.  These repairs will make the details sturdier for undergoing the paint stripping, cleaning and surface prep for painting.

I've disassembled it into basic components - cab, back head, cylinders, valve gear, frame, boiler, and smoke box front.  Work on tender will come later.

This model has a large number of very small Metric screws in two sizes. What I've done was to take photos of each component as it was removed, and put the screws back into their holes again.  This keeps other stuff for getting into the threaded  holes and also keeps the screws in their correct locations, per size, thread and length.

As I will be painting the locomotive frame first, the drivers and the hidden drive shaft and the drivers must be removed from it.  So the frame and all the things on it must be taken off. This will involve 22 more tiny screws!  I will use the same method, replacing each screw as the part it holds is taken off.   I use sytrofoam egg cartons to put the small parts in, as they may be right or left handed, forward or rearward facing.  The driver bearing retainer straps and their screws are kept as specific right and left side sets as well as for first, second or third axle.  That's 6 egg carton pockets for the driver bearing retainers, each pocket is marked specifically for a location on the frame. I will also put the driver brake shoes in each pocket per location as well.

Keeping screws in their holes while painting also keeps paint out of their threaded holes. Since the vast majority of those screws are hidden anyway, it makes no difference to me if they get painted.

Tedious, but it sure helps in not losing any of those tiny, short Metric screws that can disappear in a flash.

S. Islander

@Norton posted:

Modern urethanes use a catalyst. No idea whats on the OP’s engine. I know lacquer thinner and MEK won’t harm Lionel and MTH steam engine black but methylene chloride will remove it. Of course NLA to the general public.

Pete

I have had success removing paint from diecast Lionel/MTH steam locomotives with non methylene chloride aircraft stripper. It just takes longer. The old stuff would take maybe all of 5 minutes to remove the paint with no help. The non methylene chloride version takes 15-20 minutes, and you have to help it along with a paint brush.

There are as many methods of painting brass as there are recipes at a country pie contest. Some remove the lacquer, some don’t. some use primer and some don’t. there are many methods of cleaning and preparing the brass surface. For example, bead blasting using aluminum oxide. Using vinegar, cleaning with dish washing detergent, putting the model in a dishwasher, using an ultra-sonic cleaner etc…

This is my method for painting brass cars:

If the car is lacquered I will always remove it as it may contain dirt particles that will not show up until the paint is applied. Some lacquer can also be very thick obscuring fine details. Quite a few times I have had to do repair work on the car and soldering on it has burned the lacquer coating dark.

Using a metal pan I will start with a liquid paint remover. This works most of the time. I have had lacquer coatings that where more difficult to remove completely and resorted to using a more powerful gel type paint remover.

Then I wash all the paint remover off using a stiff brush and detergent. Rinse the model under running water and in a sink.

Next, I will treat the brass using phosphoric acid. You can get this at home depot. I used to use a product call metal conditioner made by Dupont. This is no longer available as Dupont combined the etching chemical into the primer and eliminated the metal conditioner product. Phosphoric acid will do the same thing. It will clean and etch the brass surface helping the paint to stick. Warning: DO NOT GET THIS STUFF ON YOUR SKIN.

You will then notice that the brass is now shinny like a new penny and it now important to not touch it with your fingers. Use non-powder latex gloves.

Now for the primer debate. I always prime using scalecoat gray color. This is not a true primer that is used as a substrate to adhere to the brass. It’s just a undercoating of paint that helps me when applying the final paint color. Some colors such as yellow or white are very difficult to apply to bare brass. It will affect the final color shade. This also helps to make sure that the final colors get full even coverage and that I don’t miss spots. Before applying the primer color use a tack cloth all over the car to make sure you get all the dust off. Just blowing air will not do it as it may be clinging to the model by static.

After the primer color Is applied I will bake it on in the kitchen over at the lowest setting 170 degrees for 1 hour. Turn the oven off and let it sit until completely cooled. By doing this the paint will be very hard and durable. I have tested it and the paint Is very tough and had to scratch off.

Now you can paint the final color and bake again.

Decal the car at this point.

For overcoat I like my model to be satin. Not to shinny and not to flat. I will use a 50/50 mix of scalecoat flat and gloss. No baking is required for the overcoat.

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