Article by Ray Grosser
The kit for this magnificent 1934 AAR offset side hopper car designated as HM is being offered by Kevin Sprayberry Models of Canton GA (as of this date, Kevin is still working on a web site).
These cars were owned by a number of railroads. We have some photos of the cars we are interested in building from various books. The L&N Color Guide for the Louisville & Nashville by Steven Johnson, the Soo Line freight equipment and cabooses by Ken Soroos, and the GN Color Guide for the Great Northern by David Hickcox.
The car was designed by Kevin Sprayberry around some official drawings for the cars owned by the L&N. The Soo Line cars I am modeling were built by Pullman Standard using the AAR 1934 design.
The first thing that is needed is a three ring binder with eight clear pages for the instructions. We got ours at Office Depot but they are available in a lot of retail stores. The instruction pages are numbered and the cars are assembled page by page and note by note. The instructions are well written and understandable by anyone who has built a railroad car kit in any scale, and I especially like the drawings showing the locations of each part. All the parts in this kit have etched numbers on them so they cannot be put in the wrong place, a very nice feature in a kit of this size and type.
I bought a couple of new tools for this project. Some Cleco Clamps for 1/16 holes. Before you say “No one makes them that small” you need to go to yardstore.com 715 E 10th St N, Wichita KS 67214 and you’ll find that someone indeed does make them for the aircraft industry. I bought 25 of them, but only 10-15 are needed to actually build the kit. I also got another Cleco pliers for a friend who is putting another one of these cars together.
You will need some 6” #51 aircraft drills for the tight places (drillsandcutters.com) I did not break any that I used so a couple may be all you need to get.
I got some rivet sets from KlassicTooCrib.com one for 1/16” aluminum rivets #SM10-4703 and one for 3/32” #SM10-4702. These are for solid rivets, aluminum, copper, steel.
The air chisel I bought is an Ingersoll Rand 114GQC air hammer that will work with the rivet sets. NOTE: Turn the chisel air control down to nearly off so that the rivets are set with gentle taps, they are small and if you do not have the setter turned to nearly off you will definitely mark and damage the steel components of the kit, and make the rivet completely useless. Yes, it is the voice of experience!
I was able to assemble the car based on the instructions and drawings. If you follow the sequence of construction you will have no trouble fitting the sub-assemblies together. Well I didn’t anyway.
In the end I thoroughly enjoyed the construction of the kit. Not only is this something different than what is normally offered in these large scale kits, it is extremely well designed. It may not be a novice builder kit, but a novice can build one of these if the tools suggested are purchased.
The car took approximately 30 hours from start to finish, including taking components apart after putting them together wrong. The rivet work is the most time consuming, but one at a time the car takes shape rather quickly.
McMaster Carr is a great (not cheap) source for rivets, 4-40 button head Torx screws and a T10 Torx driver, as well as other components. Button head cap screws will work, and probably look better, I just could not find any short ones in 4-40 size so I bought the Torx type.
The assembly is simple if you have assembled some other car kits with rivets. I already had some experience with a Precision Steel Car Company 40’ boxcar. I also built a Mountain Car Co combination coach/baggage car that I used a deep throat rivet squeezer I found on eBay to set rivets on that car. I bought some drills and air tools, and a couple of sanders as well as a chest of hand tools.
The car is started by assembly of the middle sections. Once I had the sections aligned and some Cleco clamps installed, it was time to start setting rivets. NOTE: If you have a wire welder you might put a spot in an unseen corner to hold the parts so as not to strain the Cleco clamps. Setting up the sides is simple and following the instructions just takes a little time.
The kit is extremely well designed and laser cut parts, but you will have to clamp up a section of side pieces and ream drill the holes to get the rivets in. This is something that is common in all kits of this sort, the holes are so close tolerance that a small misalignment of a few thousandths will keep the rivet from going through. Just ream drill all the holes and you won’t have any trouble.
The trucks I used are from Tom Bee, as well as his couplers. I like these trucks, especially his air brakes mechanism. Using other trucks will require a different bolster assembly which is the option for the builder.
When I set up the mockup of the car I discovered that it would be necessary to raise the body of the car 1/4 inch to clear something, but to be honest, I cannot remember what it was that needed an additional 1/4 inch.
When the sides were ready for final assembly, I put them on the frame and aligned them with Cleco-Clamps. Rivet setting goes very quickly with the air chisel. Most of the rivet work is “one at a time” and where I could not reach with a bucking bar, I enlisted help. I put the rivet in, my wife held the bucking plate on the back side, and a couple of tender whacks with the air chisel and the rivet tool set them.
I installed my frame to the car body with a flat head 1/4-20 screw. It is more than sufficient to hold the car body to the frame.
The car is painted with rust primer from NAPA. When the primer was dry I over sprayed it with clear gloss coat to get a smooth finish sides and ends for the stencils.
They are able to copy the font from a photograph of a Soo Line hopper in a book I have from the Soo Line Historical and Technical Society. The font is an accurate copy of the prototype lettering.
I am weathering the car to be as prototypically accurate as I can make it. I used aircraft stripper to strip some of the paint on the interior of the car then wash it down with soap and water to let it rust a little. Once I am satisfied with the appearance I will clear coat it with dull coat lacquer to take off all the shine so the car appears used.
We are very pleased with the car and it tracks wonderfully. It is magnificently fabricated by laser and it goes together well.
If you have questions about this article, please contact Ray Grosser at Ray.Grosser@Windstream.net.