How to restore Marx trains varies by model but many of the same principles apply universally. Let’s take a step by step look at how to restore a Marx 999 locomotive.
When not to restore
Early variants of the 999 with spokes in the pilot are worth more if you don’t restore them. The very last version, with the Marx logo near the cab rather than near the nose, is also worth more if you leave it alone. One thing about restoration: You can’t undo it once you alter the train.
When in doubt, I prefer just to clean it up, fix it if needed, and run it.
Common variants of the 999 don’t have much value to lose, so they’re worth restoring and enjoying. A beater 999 is worth around $20, and while you won’t add much value to one by restoring it, it’s a very attractive locomotive once you’re done.
The first question is whether to strip the old paint. Going by the book, you should. You’ll get a smoother finish overall if you do. But if the old paint is sticking pretty well, strictly speaking you don’t need to.
It’s not a bad idea to wash the locomotive in soapy water so you can get a fair assessment of its condition. Sometimes the discoloration is paint damage. Sometimes it’s just dirt.
If there’s dirt or dust that’s really stuck, try scrubbing it with an old toothbrush or a cheap paint brush. Take some pictures after you finish. Sometimes dirt shows up on camera that you don’t notice just looking at it.
The best paint for restoring a Marx 999 locomotive
The best widely available paint I’ve found for restoring a Marx 999 locomotive is Krylon Rust Tough Semi-Flat Black. As the name suggests, it’s flatter than satin, but shinier than regular flat paint. I’ve only seen a fresh-from-the-box Marx diecast locomotive in a picture, so I can’t vouch for it being a perfect match for factory-fresh paint. Based on the photos I’ve seen, I think the Krylon is a touch shinier than the paint Marx used, but it’s pretty close.
Flat paint is too flat, and if you try to shine it up, you’ll likely make it shinier than the Krylon semi-flat. So the off-the-shelf Krylon Semi-Flat Black seems like a good compromise.
You’ll want to remove the motor, the handrails, and the bell. To drop out the motor, remove the two screws on the side. Then slide the motor forward and it drops out.
The handrails are held in with two cotter pins. Straighten the handrails under the cowcatcher, then push them up and out. You should be able to thread them through the cotter pins and out the back of the engine. Straighten the cotter pins and pull them out.
The bell is held on with two tabs from the underside. Straighten the tabs with a slotted screwdriver. It’s rather thick metal so it may take some work to straighten them, and I have to alternate sometimes between the screwdriver and needlenose pliers. The bell lifts straight up once you straighten the tabs enough. I’ve covered disassembly in greater depth if you need it.
You’ll also want to remove the headlight. If you push from the inside and twist from the outside, it should pop out fairly easily.
Finally, there’s the matter of the number board. You can’t easily remove it, so I stuff a piece of masking tape down into the board and wad it into a rectangle. Leave enough extra that you can pull it out. This keeps paint off it while you’re working on it.
If the decal is still there, cut a piece of paper big enough to cover the decal. Place it over the decal, then cut a piece of masking tape slightly bigger than the piece of paper and place it over the paper. This protects the decal while you paint.
Removing the old paint
The fastest way to strip the old paint is to use aircraft remover. Spray it on and watch the old paint bubble right off. It should take about 15 minutes at most.
You can then sand or file down any imperfections in the casting if you wish, and fill any pits with ordinary epoxy, JB-Weld, or an automotive body filler such as Bondo. If there’s any damage to the body, you can fix it the same way, by filling in the damage and then filing it down to match the original.
This is another good place to use your camera. A picture can make imperfections apparent that you don’t see looking at it yourself in three dimensions. The camera’s perspective is funny that way.
I don’t go out of my way to remove factory imperfections. These were toys made to hit a price point so they won’t be absolutely perfect and that’s OK.
Marx didn’t use primer. Krylon claims its Rust Tough paint doesn’t require primer. If the existing paint is sticking OK, you can spray the new paint right over the old. If you remove the old paint, you’re better off priming it, and I recommend self-etching primer. After you prime, you’ll be able to see any remaining imperfections and fix them. Sand any raised areas with fine-grit sandpaper. Fill in any remaining pits with modeling putty or glazing putty, let it dry, then sand it smooth. Wipe the body down with a tack cloth before you paint it.
If you’re OK with some minor imperfections in your $20 train, there’s nothing really wrong with just spraying right over what’s there. The advantage to painting over the existing paint is that it only takes a thin coat to cover it. Repeat with another thin coat if you still see any metal showing through.
Let the paint dry at least overnight or, better yet, about a week before reassembly. Reassembly is just the reverse of disassembly of course.