Upgrading the Accurail ACF 4600 Covered Hopper

Back in August 2019 I wrote a blog about upgrading the Accurail ACF 4600 cubic foot covered hopper. In that blog I summarized some techniques I'd worked out over the course of upgrading several of these models throughout 2014 and 2015.

A few months after publishing the blog I acquired a handful of the Athearn Genesis ACF 4600 cubic foot covered hoppers. This confirmed what I'd already observed in my blog: the cost of the superior Genesis model is roughly equal to the cost of an upgraded Accurail version but without the work.

Now if you're the sort who just likes doing this kind of work the cost might not even matter. In my case I enjoy the work but I've done this upgrade enough times I'd rather just buy the Genesis models. But when I hit a snag trying to find more of the Genesis model in Santa Fe paint and with two already paid for Accurail cars starting back at me I decided to upgrade the Accurail model one last time... er, two last times.

Here is the factory painted Accurail car (right) next to a factory painted Athearn Genesis car (left):



As mentioned in the blog the biggest issue with the Accurail model is the running boards. They are a solid part where both the prototype and the Genesis model allow light to pass through the small openings in the running boards. Fortunately they are pretty easy to replace with etched parts from Plano Model Products. For these Santa Fe cars I'm using the gypsum pattern running boards.

The other big issue with these cars are the extra thick molded ladder rungs/grab irons. In the past I've replaced them with wire or with styrene rod, but for these Santa Fe cars I decided just to carve the molded parts thinner. It's not particularly difficult, but it takes a very sharp blade and lots of patience.

Here is one Accurail model with the grabs carved thin (left) next to one with unmodified grabs (right). Both models have had the running boards removed and majority of the paint stripped:





If you look carefully in the next photo you can see tiny dimples made by a T-pin where the new running board supports will be installed. The instructions provided with the Plano running boards include a paper template that you cut out and tape to the model's roof. Using the T-pin included with the instructions you make an impression through the paper template at each cross indicated. You can also see where the old supports used to be:



I've also discarded the Accurail roof hatches and replaced them with new round-end hatches from Tangent. These parts are intended to be used on their Pullman Standard 4750 covered hopper, so they're slightly too long, but are otherwise a close match to the original hatches used on the prototype cars. On previous models I had some leftover roof hatches from MDC Roundhouse FMC 4700 cubic foot hopper kits, which aren't as detailed as the Tangent parts but are a better match for the length of the hatches on the Accurail car.

Here the process is a little farther along. I've drilled through the roof where I made the dimples using a number 78 drill. I've bent and installed the brass supports on one side of the car in an alternating wide-narrow-wide pattern to match the prototype:



And here the running board has been bent at each end to create a vertical rise over the car centerline and installed on the brass supports using gel CA:





I also installed the crossover platforms included with the etched running boards at each end of the car. Before cleaning and preparing for paint I'll remove and replace the stirrups using A-line's "Style A" stirrups and carve off the molded grabs and install wire drop grabs at the car's corners on the sills. Most winters I'm able to use the airbrush whenever I want, but this winter has been unseasonably cold for Texas as you may have heard. So as soon as it warms up a bit I'll mix up the paint and give these cars their new coat of Santa Fe mineral brown.

 

I've had the best success with DAP RAPIDFUSE or Loctite gel CA applied when it's cold (in my garage in the winter). The Rapidfuse glue allows some flexibility but it's not quite as strong as regular CA. Gel CA is stronger and if you apply these running boards to the model when it's cold then as the model comes up to temperature the running boards will be in tension. If you apply them at room temperature or when it's warm outside then when the model is in the cold the running boards will bow and pop between the attachment points. It's backwards from how I thought it would be, but that's the way it plays out.

Here's a photo of the models in my frozen garage. The one on the right was inside the house a moment before the photo, the one on the left had been outside for a few hours. You can see how the running boards on the left are bowing between the glue joints:



Things have finally started to defrost around the house and at the moment we seem to be out of the woods as far as plumbing problems are concerned. Unlike most of our neighbors we never lost power. We got lucky.

 

I figured the metal running boards were more likely to change size based on temperature than the plastic body, but it seems like it's the plastic changing size more. Since my models are stored in the garage they are likely to see pretty broad temperature swings, anywhere from just below freezing to around 100 degrees. I've installed these running boards across a wide range of temperatures. Once I realized running boards installed in the winter did better than ones installed in the summer, I started saving those projects for the colder seasons.

This recent cold spell is much colder than we usually see, so the buckling on that running board will disappear as it gets warmer and with any luck will not return (assuming it doesn't get down to the teens again).

 

What is the difference between the ACF 4650 and 4600? I have a few of the 4650 Atlas models, but I have always wanted to see a comparison between those cars and the 4600. Genesis, Accurail, and supposedly Arrowhead in the future, all have 4600 models. I'm assuming the difference is in the length, but how significant was 50 cubic feet for ACF? Why would they have two car designs with such similar capacity?

 

This is a big help Rich thank you very much

 

Glad you like it, Vince. If you're interested in upgrading the old Model Die Casting/Roundhouse FMC 4700cf covered hoppers, I wrote a blog on those as well.

Athearn has done a really nice job upgrading those cars, so if you don't mind spending the money on them you'll be happy. If you already have some of the older MDC versions on your roster, it might make sense to upgrade them. Like the Accurail cars, you can either replace the ladder rungs or carve them down like I did with the Accurail cars.

 

I'm in the disability income arena so older cars are the norm and a little upgrading doesn't hurt

And those mdc cars fall into my fall 1979 modeling scheme

So if you don't mind yes I'm very interested Rich

 

See that that's yer dealin wit that's compliments of the Pacific Northwest y'all hope you are all safe down there

 

I don't know if the links to the blog are showing up for you or not Vince, so I'll place them here:

Upgrading the MDC FMC 4700

Upgrading the Accurail ACF 4600

Since your era is 1979, you might also be interested in modeling the predecessor to the FMC 4700, the Gunderson 4692. That version is shown in the FMC 4700 blog linked above. Basically you remove the two ribs on the carbody sides that go over the partitions between the hopper bays. The only trick to it is getting rid of the portion of the rib that goes over the lap joint (the horizontal groove) on the carbody side. I don't think the GBEC 4692 was nearly as common as the FMC 4700 that superseded it, but the difference in appearance adds some nice variety to these BN trains.

We finally got rid of the snow and ice here only to replace it with thunderstorms and flash floods. It won't be long before it's tornado season. Finally, some weather we can deal with!

 

Yup chuck berry will be there soon doing the twist and shout

Thanks again stay safe

Those articles are going to be a big help thanks much