1936 John Deere BO Radiator Curtain Fabrication

The very early model B tractors came with a canvas curtain on the front of the radiator to regulate airflow through the radiator. The main reason for this is because the cooling system didn't have a thermostat common to all internal combustion engines these days. This BO's engine is called "All-Fuel", and it runs on both gasoline and distillate (i.e., kerosene). You'd start the cold engine on gas from a small tank behind the main fuel tank, then when it was warmed up, you'd switch to distillate, which was a cheaper alternative to gasoline back then. Distillate needed a hot engine to burn well, and the curtain was the solution at the time. In order to get the engine to operating temperature quickly, the curtain would be pulled down over the radiator so the engine coolant would warm up quickly. There was then a roller at the top of the curtain to crank up the curtain to regulate coolant temperature. Later model John Deeres used steel shutters that were controlled by a rod back by the operator (then even later by thermostat), making it so the person didn't have to dismount the tractor to adjust the airflow. I don't know when shutters were discontinued but I'd guess sometime in the late 1950s, when they went to more conventional means of temperature control.

Today's project is to make a radiator curtain. My tractor fortunately came with most of the hardware. My previous 1937 BO didn't have this hardware. The main components for the curtain are a radiator guard (the mesh screen), upper curtain roller, lower curtain clips and spring, and guard spacers. I don't have the spacers so will need to make them, but they are just a standoff to hold the radiator guard 1/4" away from the radiator. Below are the components.

The curtain had little brass grommets and twist rivets to hold the curtain to the roller. Fortunately these things were still on the roller so I could know how to assemble it later. I presume they are what John Deere used, but since it's been almost 90 years since the tractor rolled off the assembly line, they could have been changed to something non-stock. I'll never know.

Time for some green paint.

The next step is to make a curtain. I found some canvas-looking stuff in the basement that looks like it will work. It's a bit soiled but that will just make it not look out of place on a tractor. This fabric was actually woven at a textile factory by the name of Karmøy Veveri (weaving mill) that my wife's grandparents started in 1937 in the town of Kopervik, on the island of Karmøy outside the city of Haugesund, Norway. This fabric was made in the late 50's/early 60's. 

Next, I measured the rough size that the curtain should be. I'll make it about 13" wide by 13" long, finished dimensions. I didn't make it as long as the radiator opening because it seems like what little information I found on the net indicated the curtain was a couple inches short of the opening, so as not to block off the entire radiator.

Although a kit is available online, anyone with a sewing machine can do this job of making a curtain. I used a Pfaff 1212, the sewing machine that happened to be set up and ready to go. I made the bottom "hem" of the curtain large enough so I could fish the lower clips and spring assembly through the hem. I hope I made it large enough. It's about a 1" hem (hindsight, I should have made it 1/4" bigger but I did barely get the thing through).

I could have hemmed the sides of the curtain, but I decided to just do a kind of overcast stitch. Also, if I'd hemmed the sides, it would have added too much bulk when winding the canvas onto the roller. The stitch I chose for the overcast is the second from the top button in the photo below. Not sure of the correct name for the stitch type, as the real overcast stitch is second button from the bottom (I think).

The overcast stitch on the right side doesn't show up very well in the photo below but you can kind of see it. After cutting the sides straight, I applied some cyanoacrylate (CA or "super") glue to help keep the edges from fraying.

The next two photos below show the finished product, before CA glue and final trimming.

This is the back side where nobody will see...

I needed four grommets or eyelets along the top of the curtain for the four rivets. It helps when your wife is a scrapbooker and has all the necessary accoutrements...

The holes in the roller are 3-3/4" apart, so I found the center of the curtain, then measured from there and put marks for the eyelets.

Below is the finished curtain laying on the nearly dry radiator guard.

I had to make spacers for the radiator guard to hold it 1/4" away from the radiator surround so the curtain's bottom adjusting clips could poke through. When the previous owner was telling me how the bottom curtain clips worked, it wasn't making sense, as there was no room for the clips to stick out the sides of the guard. At the time I didn't know he was missing the spacers. He also may not know there are supposed to be spacers. Anyway, after doing a bunch of research online, I found some forums that sort-of mentioned how things work. I found some small pipe of the right ID and OD, then cut four 1/4" spacers. (hindsight - they should be 5/16")

It's now a couple hours later, the paint is dry, and I got everything assembled and ready to install.

Ain't she purdy...