Brass Model Train Repairs

Brass model train production peaked from 1960—1990, first in Japan (Fujiyama, Katsumi, Kumata, Tenshodo, United, etc.) and later in Korea (Ajin, Boo-Rim, Samhongsa). All of these models were hand-built, made in low volume, mechanically simple, and most-importantly—they were never intended to run for 50+ years. Today's ultra-limited runs from Korea and China are more precise, but the older models dominate most collections—and they're the ones needing attention these days. 

The primary scales we work in are HO and O scales. Let's walk through some typical repair situations so that you can have a better sense for what might be wrong with some of the models in your own collection, and how we can help solve those problems.

Brass models typically come packed in a cardboard box that's filled with soft foam inserts to gently hold the model in place. The image below shows a lovely L&N 4-8-2 Mountain locomotive, along with its box, in new condition, exactly as imported in 1981. We took this picture in 2026. That's 45+ years after it was manufactured. Lovely as it appears, and in spite of it never being layout used, this model does not run. This is more of a problem with Korean models, than Japanese.  

Many brass models will not run because all of the electrical contact surfaces have oxidized. Oxidation is not electrically conductive. So all of it must be removed to make the model operational again. It's not just the wheels that need to be cleaned. There are lots of hidden areas that will oxidize too. This L&N 4-8-2 had sixty-one (61) places that needed a thorough cleaning to get this model running smoothly and reliably. That typically requires several hours of work to accomplish. 

That gets us to the model boxes themselves and how they can negatively effect brass models. Brass models come in a variety of different colored boxes. It's important to embrace the adage, "Never judge a book by its cover." 

There are tens of thousands of brass models still basically new in their original boxes that have been badly effected by the soft foam meant to cushion them. When the models were made, few people realized that the foam could go bad. It can go bad in a number of unfortunate ways. The model below is an HO scale brass Virginian AE 2-10-10-2 that was made by KMT of Japan for NJ Custom Brass. The blue-green foam inside its box deteriorated and stuck to the brass and plated parts. Had the model been wrapped in a clear poly sheet, the model would have been unharmed. It's the foam that is the culprit here. This will take many hours to restore. But we can do it.

Some of the worst foam is the YELLOW variety that came inside of model boxes made by Tenshodo of Japan. The real shame here is that Tenshodo was one of the first brass builders to produce beautifully factory painted models. The yellow foam turns to acid, eats through the poly wrapper, attaches itself to the paint, etches through the paint, then etches itself into the brass and plated metals effectively ruining many of the products that tenshodo made for the USA marketplace.

To Tenshodo's credit, eventually they put a note inside each model box warning of the dangers of soft foam inside brass model boxes, but not until after thousands of models had already been made without this warning. Here's their exact note, but pay attention to the blunder in the last paragraph. It's all they knew at the time, but it's bad advice. Models should only be wrapped in acid-free paper (if used at all) and clear USDA approved food-grade polyethylene wrappers; NOT vinyl.

Red dye staining is another problem that can happen while the models are sitting inside of their boxes. Most red foams used by Samhongsa of Korea can create the horrible red staining shown on this unpainted Sunset Models GN O-8 2-8-2. When painted models come in contact with the red dye, the result can be a ruined paint job as well. It's best to NOT touch the red foam with your bare hands as it will stick to your skin and transfer to everything else you touch too.

Severe mechanical damage can occur when models are shipped in old foam inserts. As the foam deteriorates from age, it loses its mechanical strength to stay together. Even mild vibrations cause it to fall apart creating thousands of tiny, sticky bits, that crumble and implant themselves on top of and inside the model. This model was a lovely like-new-in-original-box HO scale Fujiyama of Japan NP A-5 4-8-4. When it was shipped by the seller the foam appeared (to them) to be intact and safe to use. It wasn't. During shipment, the foam disintegrated. That allowed the model to slide back and forth again and again, causing the mess we see here and plenty of damage to both the locomotive and tender. The seller lost $400 to the damage claim over this fiasco.

Older brass models should almost always be repacked with new bubble wrap to prevent disasters like this one. Two dollars worth of bubble wrap would have prevented this $800 model from being ruined in transit. It was NOT the fault of USPS or UPS. Carriers simply move packages from point A to point B. It's up to everyone who packs the model box AND the shipping box to pack it the right way, or results like this should be expected. We're happy to make repairs, but seriously, $2 invested in bubble wrap would have prevented a $400 repair bill. Hard as we try, situational awareness about this issue continues to ruin hundreds if not thousands of brass models annually.

In many cases the original box foam that came with the model is no longer suitable to protect the model in transit. In this case, the model is an Sn3 Overland Models C&S Number 6- 2-8-0. The foam is too soft and the cut-out for the model is too big. During transit, the snowplow digs into the foam and stays there. Each bump in the road shocks the model. Eventually the entire pilot assembly breaks off the frame.

Here's the same C&S Number 60 after we effected repairs on the frame, pilot and snowplow assembly. Had the seller of this model re-wrapped it in new bubble wrap before shipping, most if not all of this damage could be avoided. Two dollars worth of bubble wrap could have prevented this $400 repair job.

Besides repairing foam and shipping damage to brass models, another of our services is full restorations of the brass itself. Brass doesn't just oxidize. It can also tarnish. Sometimes heavily. Early brass models like this C&O 2-6-6-2 weren't coated in clear lacquer before they were boxed and shipped to the USA. Later versions were coated with lacquer and that slowed if not prevented tarnish from ever getting this bad. When collectors have a prized model they want restored to a like-new bare-brass kind of look, we can do that too. Old tarnished models can look new again, with the proper process to make it happen. We made this old girl look new again. A striking difference.

Here's an HO scale GEM Ruby Pennsylvania H-10s 2-8-0 that was heavily tarnished and did not run. When models start looking this bad it can be difficult to pull them back from the brink. Often, the tarnish will pit the brass, so it's best to get these kinds of things restored before the situation grows worse.

Here's the same model after full restoration and repairs. Today it runs as good or better than it did the day it was manufactured.

Steam locomotive drives come in an endless array of designs. Some are better made than others. Older styles include an open frame motor but those are generally not suitable for DCC installation. More modern models usually have a can motor installed at the factory. Can motors can usually be added to older models if need be. But gear boxes may also have to be changed and new motor mounts scratch-built to enable the upgrade. When it's possible to do so, adding new motors and gear boxes to brass steam makes them run better, smoother, quieter. But determining what can and can't be retrofit is a job in itself. The size of the motor, its shaft, the size of the gear box, its shaft, and the space and connections in between these components becomes the critical issue when making modifications. The model largely dictates what's possible anymore. It really is a trial and error process in many situations.

Replacing gear boxes in HO brass steam locomotives can be necessary for a variety of reasons. Sometimes the gear box halves are infected with Zinc Pest. Sometimes a gear goes bad such as the worm gear, idler, or the main driving gear. We have several very detailed presentations on how to do this on our LINKS page. So if you'd like to learn how to do this yourself we walk you through everything from pulling the driver and main gear off the axle to re-quartering all of the drivers after installing the new gear. This work does require specialized tools and a good understanding of exactly how to do it. Doing it wrong can be an expensive mistake. When in doubt, let us do it for you.

Another kind of problem is something called Zinc Pest. Collectors and operators generally call us to request repair on a steam locomotive model they think has drivers that are out of quarter. If the driver centers are made of Zamac pot metal (usually black in color; not brass) then chances are good the quartering is fine. It's the Zinc Pest that is slowly destroying the metal from the inside out. Do a Google search on Zinc Pest to learn the details. It's an unstoppable force that fragments the metal, caused by metal impurities, that loosens the driver centers on the axles and makes the wheels wobble, if not fall off the axles. It cannot be stopped or repaired. Here's a shot showing a Van Hobbies CN 2-6-0 with severe Zinc Pest on all of the drivers. This model got sent back to its owner. No can do. Be aware, Zinc Pest tends to effect Zamac gear boxes and Zamac frames in both steam and diesel locomotive models.

The raging Zinc Pest problem is important enough to this hobby that we show a few more images of what's happening NOW in thousands of brass models with Zamac gear boxes. It's everywhere in certain HO, S and O scale models. Likely others too. The model pictured is an O scale Milwaukee Road ES-2 Electric imported by Overland. Our images should explain the rest of the story. A solution needs to be found.

For the do-it-yourselfers out there looking for a simple and inexpensive way to get some of your brass models operating again we sell Variety Packs of replacement motor and gear box tubing. Our tubing is heat-resistant and won't crack, melt or turn to stone like most of the tubing used in older brass models. It works in steam, diesel, and electric models. For more information please visit our page called Replacement Motor Tubing. If you'd like to buy a pack today you'll find them for sale in our eBay Store.

That gets us to the uglier side of the brass model repair business. We're talking about models that have been ruined from accident, neglect, and profound lack of situational awareness. Let's start off with a brass Pennsylvania coal tower model. The unpainted model on the right was shipped to us from a well-known dealer that paid little attention to the fact models like these CANNOT be safely shipped to anyone, anywhere, at any time. These are hand-carry-only kinds of models, best sold at a show or in a retail shop, so the buyer can carry it home himself. Compare and contrast the unpainted wreck with the beautifully painted and weathered model we delivered to a client in Texas. Our model is still in this exact condition today, proudly displayed in the owner's home. Brass coal tower models are easily destroyed during shipment. Crossing your fingers in the hopes that yours might arrive unscathed is not an appropriate plan of action. If you buy one online—PLEASE GO PICK IT UP IN PERSON—or you may have to throw it away when it arrives. Models like this are rarely repairable, and even if they are—it will usually cost more than what you paid for the model.

Many of y'all might be wondering, why are brass models so susceptible to shipping damage these days. Here's a picture I snapped showing how brass models arrive in this country at the importer's warehouse. They come from Japan, Korea and China boxed up in large containers. Each holds anywhere from 4-6 larger models to as many as 40-60 smaller models. The shipping containers are large, they're heavy, and they get moved numerous times to travel from the factory to the airplane, from the airplane into customs, then from customs to the importer's warehouse. But NOTHING is tossed around. These large boxes are moved from place to place with a pallet mover or fork lift. They're never tossed around inside the back of a truck. They'e not subjected to carrier sorting facilities where the conveyor belts run at 25 mph. That means coming into this country the models are handled VERY gently. There's rarely any shipping damage in this situation.

But once those larger containers are opened and all of the models are placed on shelves to fulfill orders, the situation changes drastically. The dozens of very large shipping boxes quickly turn into thousands of much smaller packages that can be thrown about like footballs. This is where shipping damage is most-likely to occur. Especially if the models are decades old and have rotted foam inside the model boxes. And why we remind people that it's up to EACH OF US to repack brass models before ever handing them to a carrier for delivery. Placing a 'Handle With Care' sticker on the outside of the shipping box matters very little to today's automated delivery systems.

If you've never been inside a modern carrier sorting facility, this older image will give you some idea of what happens when things go wrong. And they go wrong every day of the year. Modern sorting facilities can have conveyors suspended from the ceiling 30-40 feet above the concrete floor. When boxes hit the floor, and other boxes pile up on top of them, what happens if your model isn't packed very well and the box that falls on top if it weighs 80 LBS ?

Every day of the year, somebody's new brass model purchase is gettin' crunched. Damage this bad cannot be repaired. It's our hope that showing these DDA40X diesel models will help others to understand what can happen when it all goes terribly wrong. Using old foam, using boxes too small or flimsy, and not packing models tightly into their boxes with new bubble wrap can lead to this kind of problem. It's up to every person packing a model to make certain the model is re-packed properly inside its model box then placed inside a much larger, heavyweight shipping box, packed with lots of bubble wrap. Carriers simply move packages from Point A to Point B. If sellers don't pay attention to what they're doing in their own shipping department, then disastrous results can be expected. 

Then there's the nose-dive-off-the-layout kind of problem. 99 times out of 100, the solution here is to simply buy another model and put the wrecked one into a wreck scene on your layout. When real locomotives are wrecked badly enough, they get parts'd out and scrapped. That's what happened to Overland Models 6919 here. It's impossible to repair this kind of damage because in order to do that you'd need the original dies and soldering jigs used to create these complex parts. Word to the wise—don't drop models on the floor. Don't drop things on top of models either. If you do, it's generally GAME OVER. Most of the time our repair shop operates like a hospital triage center. Some repairs are simple, others more complicated, some are very difficult to bring back. Normally, the hat we wear while performing our craft is that of the Repair Technician. But when things go this bad, we must wear a very different hat—Coroner. It's then our unfortunate obligation to call the model's owner to give them the bad news. 

 

We could go on and on with more and more repair examples, but frankly, we already have 300+ presentations with 2,000+ images on our FACEBOOK page. We add more to that database of technical-modeling-brass-collecting-goodness every week of the year. So if you want to learn more about brass models and how to service, repair, restore, paint and weather them (for FREE) then all you need to do is visit us on FACEBOOK by clicking HERE.

If you don't currently use FACEBOOK but are wondering if our list of brass presentations might make that worthwhile for you, you can see the complete list of presentations on our LINKS page. FACT—A lifetime subscription to every past and current model railroad publication (and websites) won't provide 2% of what we're providing FREE of charge on our FACEBOOK page. Invest in yourself by embracing our FACEBOOK page. It's the stuff you need to know about if you're serious about your brass model trains.

Cheers!

Jeff Lemke