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QuickAF Flat Car Conversion
American Flyer®
Connecticut S Gaugers

For Scale, Hirail and American Flyer S Gauge Model Railroaders

Quick AF Flatcar Conversion

by Pieter Roos

Not trying to take anything way from American Models new flat car, but a nearly identical car can be built rather easily from the AF plastic flatcar. The two cars appear to have the same or very similar prototypes, an unusual 46 ft. length with 12 stake pockets. American Models showed a C&NW prototype in one of their advertisements that is a 46 ft. 13 stake pocket car (the MP and NP prototypes shown in the same ad are not 46 foot cars). Could the same prototype have been chosen by Gilbert for the original AF C&NW flatcar? The fastest conversion is to use the Ace conversion bolster glued or screwed over the existing AF truck mount. This is probably the best option with the cast metal AF car unless you have a very well equipped metal shop. The Ace conversion has two disadvantages. The first is it leaves the original deck with visible holes for truck mounting rivets, stamped stakes or other loads all showing. The second is that the resulting car is too high. Most prototype flatcars really nestle down over their trucks.

To convert the plastic flat, remove the trucks and lay the car deck down on your workbench. Take your razor saw (X-Acto, Zona or Atlas Snap-Saw) and carefully saw off both ends of the car, keeping the saw blade vertical and flat against the inside of the end sill. Once the ends are off, set them aside. Now slice off the sides in the same manner. The sides take more work because of the length and depth of the side sills. It can be tricky to cut deck flush with the inside edge of the casting if your saw has very little blade below the back piece. If you are using an Atlas Snap-Saw for example, you may need to scribe a line on the top of the deck just inside the sill edge and cut from the top rather than the bottom.

Once you have separated the sides and ends from the deck, clean up the backs with a coarse file. The sides have the molded board ends on top, these may be sanded or filed off. The ends will also have a partial board on them. Some flatcars have a metal piece at each end of the deck and the remnant here is perfect for that purpose. For prototypes where the wood decking extends all the way to the end, cut or file off this bit the same as the sides. If you plan to strip and re-paint the car, this would be a good time. I scraped off the numbers and replaced them with decals later, as well as adding some more dimensional data, but left the roadname and capacity information alone. Now you can cut off the molded steps and carve off the grab irons and drill the holes to mount their replacements. I used large TOT brand staples for the steps and brass wire for the grab irons, and left the cast on end bolts (although it might be easier to carve them off and replace with Grandt line NBW castings). Mount the steps and grabs and fix them in place with ACC. The brake staff hole can be filled with a bit of styrene or epoxy and drilled for a new, finer wire staff after it dries. Don't apply the staff and wheel until the car is otherwise complete. If the body you started with has any broken or cracked spots, now would be a good time to repair them with strip styrene or filler.

Once all cutting and drilling is complete, make a new sub-deck from 40-60 thou. styrene and re-assemble the sides and ends carefully around this sub floor. I used the flat bottom Ace bolsters (not the conversion bolsters) with the 5 1/2 foot truck center spacing. Check the bolsters against the width of the assembled car. I needed to trim a bit off each end as well as cutting back the coupler box mount enough so the end of the box would extend over the end sill of the car with the box mount butted to the inside edge of the end. The Ace metal is very hard, so you may need to use a Dremel tool and cut-off disc (VERY CAREFULLY) to do the trimming. Fortunately, the amount trimmed does not have to be exact. Tap the coupler and truck mounting holes and mount the bolsters, being careful to keep both holes centered if you want the car to run well. I used 5 min epoxy to mount them, making sure to build up a fillet through the bolster mounting holes but NOT the truck or coupler mountings. The mounting might be more robust if you fasten the bolster with screws but the styrene sub floor does not give them much to hold onto. You should also reinforce the side to sub floor joints with fillets of epoxy. At this point you must decide how to handle the underframe. If your layout is fairly low, you can probably skip it altogether and no one will be the wiser. If the AF body you started with had a full fish belly (I've seen at least three variations on the underframes of these cars) you can do as I did and saw it off the deck. This is a lot of work, using a hacksaw or deep razor saw to cut parallel to the remaining deck. It may be easier to simply build one up from sheet styrene. Make sure the trucks have room to swing! I didn't add any brake gear, I defy anyone to tell while the car is on the track. Add weight in the center of the car, then spray the underside grungy black. Touch up or paint the car body and apply any decals to match your prototype. The Champ HO data sets are a big help here; many have data slightly large for HO.

Now you're in the home stretch! The real wood deck is easier than you think. You do need to pick an appropriate size of wood. Commercial basswood strip is fine, even balsa will work. I had a package of Campbell profile switch ties (HO scale) lying around for years that turned out to be perfect. Once more, you can choose from two prototype styles. Some cars have the deck like the original AF car, even with the sides of the car body. For this style, cut all decking pieces the same length. Other cars have decking which extends out even with the outside of the stake pockets (like the S Helper car). This style decking requires that the boards that cover the stake pockets be cut shorter to allow stakes to be inserted. Either style would be correct for these cars. Stain the wood, then use a NWSL chopper or your own jig to cut the wood to identical length. Coat the sub floor with a water-based glue like Elmers acrylic contact cement and begin laying on the deck pieces. Be sure to line up the ends carefully, check them with a straight edge to be certain each board is in line with its neighbors. Also double check that the planks are centered on the car width. If you are modeling the style with the overhanging deck, you will need to align the shorter boards over the stake pockets by eye. When done, set a metal ruler or other long weight on the deck while the glue sets. Once the deck is dry, some of the boards on the overhanging deck may need trimming to provide full clearance over the stake pockets.

The brake wheel is the last part you need (except for your choice of trucks and KD #5 couplers). I used one from the MDC HO old-timers series, a large part with curving spokes, which is just way too big for HO. Drill out the hub for a three scale foot length of wire, drill the brake wheel mount on the car end to match and mount the wheel. Most flats have a brake wheel that can be dropped flat on the deck to clear long loads. One way to protect the fragile wheel if your car is subject to rough handling is to push the brake rod all the way through the mounting until the wheel is flush on top of the deck planking before gluing it in place. If you do this, make sure the bottom of the rod is high enough to clear the track and any crossings or other obstructions. Of course, the AF stake pockets are not hollow so it is difficult to add loads that require stakes.


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