# Bowser 4-6-6-4 Challenger Build



## Murv2 (Nov 5, 2017)

(Note: Another MTF member asked for a build report on this kit rather than a review so instead of writing up my impressions after finishing I did a blow-by-blow as I worked. The result is this massive missive.)

One of the really great things about model railroading for me is building things. While I enjoy plastic models of tanks and ships and even buildings I love that on a railroad I can build something that actually moves. Instead of models that end up on a shelf rolling stock ends up racing around the layout like a giant snake. I really like building the old cardstock, wood and metal kits before plastic made our lives so convenient. My special thrill is steam engine kits. Gently harnessing dozens of parts together that all would rather go in different directions then put them to work pulling trains is a great hobby (definition of Hobby: a productive way to waste time.) (Note to self: Quit waning poetic.)

The great steam kits are no longer in production (at least that I can find) but they are still out there on Ebay and from resellers. In my lifetime I’ve built three switchers, the General (three times), a Prairie, Mikado and Pacific. They work fairly well, mostly better in reverse than forward. The penultimate challenge for an engine modeler is a mallet. There are a few out there in kit form: Mantua’s 2-6-6-2T, a Pennsylvania Duplex and UP Challenger and Big Boy all by Bowser. (inherited from Penn Line I believe). (The ultimate challenge is to build your own locomotive from scratch, not ready for that yet).

So when Christmas rolled around I went on Ebay (Bad mistake, I always end up with “Gotta have that!” purchases for things I don’t need) and found a Challenger still in the box. Santa doesn’t know what to get me anymore so a quick link forwarded to SWMBO and it found its way under the tree on the big day. Naturally I didn’t notice the tender isn’t included so another run on Ebay and a tender was on its way, as well as a tender-shaped wood block I’m hoping to turn into a UP water tender someday (“Gotta have that!”).


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## Severn (May 13, 2016)

And I get their eflyer and they just had or it's ongoing a big fire sale in pieces and parts. And I recall a few unfinished steam engine carcasses. Could make a kit maybe!


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## Murv2 (Nov 5, 2017)

Flash

While most instructions say you should inventory parts first and mail in a request for missing pieces (some kits even have forms for that), I usually don’t for the simple excuse that there is no recourse. Even if the companies exist they stopped making steam locomotive kits long ago and replacement parts are not available from the manufacturer. When I find things missing I end up either looking for them on Ebay, making a substitute from scratch or doing without.

Instead I start with flash removal. The metal these kits use is some kind of alloy, more brittle than the alloy used for toy soldiers but not as brittle as resin for example. It may be Zamac or something similar. Zamac cancer is a big concern for model railroaders but I can say that I’ve only seen it in one part in steam locomotive kits (the cab of a Roundhouse Prairie), so I suspect whatever alloy is used for these locomotives is something else.

Anyway, there are three kinds of flash: Paper-thin sheets, jagged chunky lines and shelves. I suspect the paper-thin sheets come from the seams in the molds. They like to fold over and hide until after you’ve painted the engine then you notice them, fold them back and they reveal a shadow in the paint you have to patch. The jagged chunky lines come from pouring channels in the mold. After the mold cools these channels are broken off using a pair of pliers or snips and the resultant flash is thicker and harder to be rid of. Shelves are places where two parts of the mold are misaligned and as a result one edge stands proud over the other.

I use files and a dull knife to remove flash, then an emery board to remove file marks. A knife will cut off the paper-thin sheets easily but even if you start with a sharp knife the metal will dull it quickly and either you end up using a dull knife or going through an entire pack of replacement blades. Just be careful and remember not to put any body parts you are fond of in front of the blade.

For files, a gunsmith friend informs me there are two kinds, a rough file to remove material and a fine file to dress the metal afterwards. This was a revelation to me and I strongly recommend using a mixture of files, it makes things go faster. Use your fingers to feel for sharp edges (gently) and file them just enough to take off the edge. Often sharp edges will look OK in bare metal but will appear uneven when painted. Also, if you can see a straight line before the part is painted you’ll be able to see it after you paint it. Be careful when filing not to round surfaces that should be square and only take off enough to render seams invisible.

Three of the jagged chunky lines on my boiler had pits deep enough to be visible after I finished filing them down, a little green putty took care of them. The cylinder heads had shelves. After filing on them for a bit I put some green putty along the seam and after it dried filed them back down. Rather this than just muscling through with the file to reduce the amount of metal taken off. Unfortunately my green stuff wasn’t juicy enough and flaked off while I filed it. Hopefully people won’t look too closely at the bottom of the cylinders.

One last comment: Initially I only removed flash from the loose pieces in the box, leaving the pieces in separate bags for now. It is much less likely to lose pieces if they stay safely stored in their bags until you attach them to the engine. Flash removal is ongoing process in this build, especially if, like me you don’t have the craftsman gene and continue to find flash during the build you missed in the beginning.


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## Murv2 (Nov 5, 2017)

Drivers

Unlike most engines where there are visual cues to which side of the drive wheels are insulated, this model doesn’t really have any. I ended up sparking the wheels with an old transformer to figure it out, then put red dots on the powered side on the inside of the wheel. I did it in a couple places because I’ve found that paint will often rub off. While checking I noticed the tires on the insulated side had a slight greenish tinge to the metal. Also, the ends of the axles had rust I scraped off with a knife blade and I polished the dirt off the wheels with a track cleaning eraser.

Naturally when starting I assembled the back frame while the instructions talked about the front frame, hilarity ensued as I couldn’t figure out why they’d instruct me to get the screws from the pilot truck baggie. All part of the fun for me… After I assembled them, seated the bearings (bronze, I think. I often wonder if bronze and brass bearings really matter or if they are just advertising gimmicks, like remote start in a car), pushed it around on the table a bit, took it apart, greased the axles again, reassembled it, seated the bearings again and after rolling it around on the table a bit I ran in the grease by the method pictured.


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## Murv2 (Nov 5, 2017)

(Continuing) Then did the same for the rear truck. During the process I found out where the loose washer I found in the box went. BTW, other than one baggy all the rest are designed to be sold separately, meaning that screws aren’t all in the same baggy. Understandable but my master plan for keeping all the parts in their own separate baggies isn’t working out so well.
Either one of the crank pin holes was buggered or I cross-threaded it when I gently put the crank pin in. After messing with it for a while I ended up finding a 0-80 brass screw and screwed it in to reset the threads in the hole. Scary moment, replacing a drive wheel would be difficult.
Be prepared to take your drive train apart A LOT. There is always a tight spot when rolling it and the only way to figure out what’s wrong is by taking pieces off until you figure out where it binds. It’s made harder by the fact that if you take one side off the other side goes catawampus and you can’t repeat the experience without both drivers. Stopping at the bound spot then checking which drive rod and wheel is loose helps determine which hole needs filing.
(Note to self: when filing rivets off drive rod guides make sure you file off the inside rivets on both sides)


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## Murv2 (Nov 5, 2017)

Walschearts

To start with let's try to get the spelling right. I must confess there are some words I can never spell without checking them like 'necessary' and 'Walschaerts' is one of them. I ended up asking the Wicked Podiatrist for the right spelling and found I only got two letters reversed (I can spell podiatrist right the first time).

Anyway the Walschaerts reversing valve gear is one of the really cool things on late steam engines (by late I mean the last half of their existence). All the little rods move in a bizarre fashion and watching them run is mesmerising like watching the inside of a giant clock in a clock tower.

The eccentrics are clamped in with the smallest nuts and bolts I’ve seen. I had to use a knife edge to screw them in, my jeweler’s screwdrivers were too small. I spread the notch on the clamp and then lined them up on the drive rod. It would have been nice if they said where to position the offset hole (it is later in the instructions). Hopefully I remembered right to set them up trailing the pin…

At this point I got to one of those stalls in construction. I couldn't find a jink in the front drivers and the shear complexity of all the little pins and rods threw me (compounded by Spring Allergy Medication Haze) and I built a passenger car to relax before I resumed working on the engine.

Once you read the instructions carefully, examine all the parts and lay everything out you should be able to get it all riveted together with only a couple major mistakes. BTW, if you do find you riveted something together wrong you can gently squeeze the rivet with a small pair of pliers around in a circle until the rivet will come back out. They are brass so you should be able to reuse them. Fortunately there are several spare parts in the baggy.

Now this engine has a bunch of brackets screwed down to the frame and everything is riveted together so it may not be impossible to take it all apart once you assemble it but it's pretty darn close. I'd planned on assembling the gear, then taking it apart to paint it but now that's together I'm just going to paint around it as best as I can.

And the front drivers still have a damn jink...


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## Murv2 (Nov 5, 2017)

Power

After struggling so hard with the drive train the power assembly went relatively easy. The only parts that required some messing with were the bearings on the front worm gear. They are two separate housings that go into two separate holes and the worm gear shaft runs through both. It is very likely the shaft will bind when you first install it. Then you wiggle the housings around with pliers until the shaft runs freely. Overall the design could have been done better, for example making a one piece frame with both bearings on it but it helps that the bearings swivel in their housings once you break them free from the casting metal.

After this you get to run the engine on the track! At this point I stopped to build the tender (next paragraph) and then I found out just how deep the depths of stupidity can go. I checked the powered side of the drivers (remember the red dots?) and put the insulated tender wheels on that side, but the engine didn’t work. So I checked and found that I’d put the tender wheels on the wrong side anyway (looking at the engine from the other side). Then I noticed there were only red dots on the front drivers. Then I realized I’d put the powered wheels on one side on the rear drivers and the opposite side on the front drivers. D’oh!

So after careful cursing, disassembly, reversing the drivers, reassembly, tweaking and testing the engine was ready for the track. I have to say, it is an awesome moment when the engine finally races around the track without any ugliness.


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## Murv2 (Nov 5, 2017)

Tender

I bought a tender on Epay that was just a wood block in the shape of the tender. I knew it but figured I could make it work. Then a few days later I found a full tender, ‘Bowser SP-1 Semi-Vanderbilt Tender 1-150001’. This is the one on the picture of the Bowser kit and I went ahead and bought it. Eventually I hope to turn the wood block into a water tender.

Anyway, the tender is basically a thick metal alloy tube shaped like a tender with a bottom frame that screws in and a front plug with all the detail that pretty much goes in by filing it then pounding it in. There are also brass ladders that require cutting, bending and fitting, grab rails and a couple wires bent into water level indicators. The rear ladder looks pretty spiffy if you can get it bent right.

The trucks are also metal alloy with brass wheels and a brass bar that screws underneath. What I consider a design defect, you can’t screw the truck into the tender unless you completely disassemble it as the screw that goes into the tender is under the brass bar. On the other hand, they roll pretty good.

They provide a horn hook coupler but a Kadee #5 goes in without any problem, it’s even the right height. Having used the tender to run in the engine my only complaint is that it wobbles a bit, I’ll need to look at that sometime.


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## Murv2 (Nov 5, 2017)

The Rest

After you have the drive system working on track the rest of this kit is pretty straight forward.

That is, except for a common complaint I have with all these kits, the cast parts that are attached to the boiler by lining up a couple pins and pounded in. THESE NEVER WORK RIGHT! I’m not a handy guy, but I’ve bent and broke more pins than even a stooge like me should expect to damage. Heck, I drilled out and installed a brass pin then bent that too! Also, you pound in one side and the other pops out but if you try to pound centered between them one doesn’t go in the hole and the other pops out again. And there’s always some detail to flatten with your mallet or punch. I almost always end up gluing these in.

Steam Pipes are pretty easy, the rear had to be filed on a bit at the front to fit the brass ferrule. One of the front pipes has a little round shelf around the screw hole that looks like it’s supposed to be there but it needs to be filed off or the front pipes when they pivot will make the boiler lift off the front support and it won’t line up right.

The pilot is nice but the cow catcher wobbles a bit because there isn’t enough contact with the rest of the pilot where the pins go in. The trailing truck is just a U shaped piece of alloy, making it easy to put together but only time will tell if it runs well. Lead truck came as one piece, but the little spring that’s supposed to keep it centered went twang and disappeared into a dark corner of the basement. The instructions say it’s optional anyway. The bell is really neat, including a clapper.

Hand rails come together easily, but the kit comes with one long and one short wire, the long wire is cut in half for both handrails along the boiler and if you use if for any other handrails one side will be too short, guess how I know. I ended up carefully cutting the short rod so the joint would hide inside one of the stanchions and fitting the remainder of the long rod (now a short piece) to finish the rail.


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## Murv2 (Nov 5, 2017)

Painting

After finishing the details I partially disassembled the engine for painting. That went fairly well using spray cans, first satin black, painted the silver, then decals and flat coat. But the engine decided I needed a final slap in the face before I finished and the flat coat went frosty instead of “Crystal Clear” (says so right on the can) This happens occasionally when spraying in a humid environment (like the garage in late March in a rain storm). Fortunately I knew the trick, hair of the dog… Another coat in the far corner of the basement (when the family was asleep) put it right.

I didn’t take the running gear apart, instead opting to carefully paint around it by hand. Not the best way to work but better than trying to make the valve gear work right again after taking it apart. There’s a lot in there that could be painted and if I were smarter I’d paint the whole thing before starting the build.


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## Murv2 (Nov 5, 2017)

Conclusion

I haven’t actually got the engine working 100%. If experience is any teacher I’ll be messing with this engine for a long time. That said, there is something really satisfying about finishing a monster like this. It’s big, complex and I look forward to seeing how many cars it pulls, once I work out that damn jink…


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## Severn (May 13, 2016)

Fabulous!


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## Murv2 (Nov 5, 2017)

Not sure why it repeated my text on the last few posts. Anyway the crank pins keep backing out and jamming against the firebox so I epoxied them in. Now it's still going herky jerky, have to figure that out too. the fun continues...


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## Jscullans (Jul 8, 2019)

I have an older tenshodo brass Santa Fe blue goose model that I really like a lot but it needs the axle bearing blocks either replaced or bushed up to take the “wobble” out of the wheels. Tearing apart the drive rods to remove the axle sets terrifies me. That is a rather expensive model and I don’t want to destroy it by doing something dumb.


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## 97128smith (Dec 10, 2021)

Murv2 said:


> Drivers
> 
> Unlike most engines where there are visual cues to which side of the drive wheels are insulated, this model doesn’t really have any. I ended up sparking the wheels with an old transformer to figure it out, then put red dots on the powered side on the inside of the wheel. I did it in a couple places because I’ve found that paint will often rub off. While checking I noticed the tires on the insulated side had a slight greenish tinge to the metal. Also, the ends of the axles had rust I scraped off with a knife blade and I polished the dirt off the wheels with a track cleaning eraser.
> 
> ...


That is thinking outside the box lol good thinking.
Between dad n I we have 13 challengers and 3 Bigboy kits all Bowser so we know.


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