Written by Jim O’Connor
This PSC (Precision Steel Car) boxcar kit may not be for everyone, but it might be perfect for you. It’s more involved than a simple “bolt-together” model. Two things make this model a more advanced build and they both involve joining metal. The first is welding. You will need access to a wire welder. Unlike “stick” welders, wire welders can be turned down enough to allow you to join the sheet metal sections without burning them up. The other method of joining metal in this project is riveting. The boxcar kit is built much like the prototype, with hundreds of rivets. Many of the rivets are decorative but some are structural. Rivets are a surprisingly good way to join metals even at this scale but with well over a thousand rivets, it’s a long process.
I was impressed when I uncrated the kit (right). Everything is cut from flat sheet metal (below). The frame is the first thing to build and it fits together like an old egg-crate with interlocking slots. I test fitted the frame sections, then degreased them with paint thinner. You’ll find all the metal is bare and has a thin oil film covering to keep it from rusting. If you don’t clean each piece, you won’t get a good weld and you won’t be able to paint it later.
After welding, you may need to clean the area around the weld. Top-end welders use a shielding gas such as argon to keep oxygen from reaching the molten metal during the welding process. I’m using an inexpensive “flux wire” in my welder. Using this type of wire doesn’t require a welder that uses shielding gas, but it does, however, leave a much dirtier weld area to be cleaned up (left). I used a wire brush and some solvent to clean the area after the weld had cooled. In some places, I sanded the weld flat.
Most, if not all, of the welding is done from the inside or underside so it doesn’t show in the final model. One technique used with this kit is the plug weld (far left photo) where an access hole has been provided. This allows you to join the 2 metal sections from the back. Simply run a puddle around the inside of the hole to join the sheet that contains the hole to the piece below that hole. The sliding “side doors” use this method. After welding, I sanded the area flat.
As I said at the top of the article, this kit requires hundreds of rivets. It does, in fact, require well over 1,000 rivets. Rivets are a permanent mechanical fastener. We’re talking “real rivets” not “pop-rivets” or “blind-rivets” which many of you are familiar with. Don’t even think about using pop rivets here. Pop rivets are not fast and will leave your project looking home-made. A traditional rivet consists of a cylindrical shaft with a head on one end. The other end is called the buck-tail. The rivet is placed in the pre-drilled hole. The tail is smashed or mushroomed or rounded over with the rivet gun. The tail end now appears to be just like the head end. Rivets are not included with the kit and must be purchased separately. Rivets come in all sizes and types of materials like steel, brass and aluminum.
The kit’s instructions don’t specify, but I purchased aluminum rivets from McMaster-Carr. Aluminum rivets are easy to drive, but I’m not sure how well the paint will stick to them after several years. We’ll find out.
Most of the rivets holes are pre-drilled. But, in order to align the parts you will need to use temporary “clecos” before any rivets are set. Clecos are easy to use and reusable. At less than $.50 each, they are worth the investment.
Place the clecos to hold sections when you rivet. Rivet from the center to both ends. If you start at one end and work your way to the other, you may end up with extra material and a buckled piece.
You can use a “rivet squeezer” as the instructions suggest, but I used a pneumatic rivet gun (right). It’s economical and it works in more tight locations.
To drive a rivet, place it in the pre-drilled hole. Some of the tail will stick out the back of the metal. Place a “buck” against the head (this keeps the rivet in place while it’s being driven) and, using a pneumatic rivet gun with a rivet setting bit, smash down the tail section. The tail will mushroom out which will have
the effect of locking it into the hole. If you ever need to remove the rivet, you will need to grind off one head or the other before punching it out of the hole.
The kit can accommodate almost any truck and coupler, but you need to mount whatever is necessary to get your brand of truck to work properly. I welded a nut to a flat plate and mounted that to the bottom of the car (not shown) to accommodate the Tom Bee truck. With other designs, a king pin may need to be mounted.