RPM 1/72 Mack AC 'Bulldog' Type EHC (1919) Build Review

By Llarry Amrose

Background

The second decade of the twentieth century was a critical one in many ways. The Great War (WWI) saw the introduction and development of technologies that were new to warfare – not just aircraft and armor, but also motorized transportation. It was also critical for automotive manufacturers, as they competed to take advantage of a rapidly growing market, though many would not survive the decade. Mack Trucks would emerge from a maze of corporate mergers and sales as a survivor, due to the success of their AB- and AC-series chain-driven trucks. Over 40,000 AC-series trucks would be built from 1916 through 1939, including 4000 for the U.S. Army and 2500 for Britain during WWI. The story goes that it was British “Tommies” who dubbed the Mack AC as the “Bulldog”, for its durability and tenacity, a nickname which the company has proudly carried ever since.

The Build

The AC was provided with a variety of bed configurations, and RPM has kitted a number of them. The end-opening box contains two sprues of parts and a decal sheet, which seem to be the same as in all four released versions. The differences come down to which bumper, wheel, cargo bed parts and decals get used, and which are discarded. The detailing on the parts is pretty good. Some care will be needed to separate some of the smaller pieces from the sprues; the connections are not excessively large, but still not quite as fine as in kits from some of the larger makers.

The instruction booklet has a good parts diagram showing which parts to use. Construction is broken into a large number of steps, but this keeps down the number of pieces involved in each (a big improvement over the last RPM kit I built…). This results in a number of subassemblies, some of which, with care, can be performed out of sequence, allowing for drying time without coming to a dead stop.

Still, these very instructions are probably the weakest point in the kit. A number of the illustrations are imprecise and potentially misleading. I fell afoul of Step 3, in which the orientation of the projecting pin on piece A43 is not made clear. In Step 21 we find that the clutch lever needs to attach to it, but I had mine rotated 90 degrees around, and in fact had to eventually carve it off so it did not interfere with the positioning of the drive shaft. Another critical step is 16, where the rear axle is placed so as to meet up with the chain drive in step 20. There are arrows drawn from each end to the frame, the front one is correct, the rear one is not.

Now that you’ve been warned, you should not encounter any significant difficulties. Test fit all parts thoroughly, and be sure to look ahead and see how the current assembly will mate up with the others. Look ahead, think ahead and take your time, and you will be rewarded.

When you go to attach the hood down over the engine to the lower frame, there will be a fairly prominent seam. Don’t fill it in, this seam is quite visible in old pictures of the real thing.

I did have a happy accident along the way. Four of the tiniest pieces are tie-down hooks at the four corners of the frame. After attaching them and letting them dry, I discovered that I had accidentally bent one over in handling. Ends up looking like a nice bit of incidental damage from backing into something, or trying to move the proverbial immovable object.

Painting and Finishing

The back of the box has a couple of nice color profiles and a row of Humbrol paint numbers and color blocks, and that’s it. The first page of the instructions reproduces the profiles in grayscale with the decal callouts. What’s not there are any detailed painting directions for the engine, chassis or interior. The profiles show enough to give you some hints, and the rest is up to you. The main exterior color is given as H30. I went with PollyScale’s PC-10 Brown Drab, which is actually rather olive-y green. It’s the main color used for British aircraft in WWI – I figured motor vehicles, being equally new to warfare would end up a similar shade.

I found it worked best for me to do a mix of painting individual parts on the sprue, and completed subassemblies. By the time I had the chassis and engine complete, just about everything was done except for some final touchup.

The decals were tough. The sheet has large surrounds of carrier film, which nearly blend together into a single sheet, so I trimmed close to each marking. These decals took forever to come loose of the backing paper, but handled well once they did. They seemed pleasantly thin, and yet were durable enough to survive the abuse they took before coming free.

For weathering, I used various colors from the Tamiya Weathering Masters sets. These are 4 “makeup cases” each with three pastel shades and a small applicator sponge. They stick better than standard chalk pastels and survive handling better, even unsealed. The application method allows for a subtle touch when desired, though it’s not that easy to get into tight corners.

Conclusions

Softskin vehicles are interesting and fun to build. They’re not just boxes with gun barrels and tracks, as tanks can seem to be at times. RPM has done a fine job of capturing the detail of the engine and transmission in a small scale. While I wouldn’t recommend this kit to an absolute beginner, anyone with moderate experience should do fine. The key is to plan ahead and test fit constantly, and heed the warnings I’ve given above. I would even go so far as to recommend this kit to someone looking to break into shorter-run kits

My sincere thanks to Squadron Mail Order for this review sample!