Innovations in Moldboard Plows

Let's Talk Rusty Iron: John Deere's steel plow wasn't the end of innovations in plow moldboards. Inventors had a variety of solutions for dealing with the sticky gumbo soil of Texas, including lubricated and heated plows.

Plow Moldboard Innovations 1

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We've all heard the story of John Deere and the plow moldboard he fashioned and polished from a broken steel saw blade. That innovation largely solved the problem of sticky prairie soils gumming up the iron plows that had worked so well in the East. Some soils, however, defeated even Deere's famed "singing plow."

In certain areas of the Southwest, particularly in Texas, there is a sticky "gumbo" (or black waxy soil) that, especially when wet, adhered to even the smoothest and shiniest steel moldboards. The mud soon built up to the point that the plow would not cut or turn a furrow and became impossible to keep in the ground. The gumbo had to be laboriously scraped off by hand and soon built up again.

I was familiar with slatted moldboards that offered less surface to which gumbo soil could stick, and I assumed that was the only solution to the problem. However, I was rooting around among a bunch of old plow patents the other day and found other solutions I'd never heard of, solutions that seem just a little fanciful.

The first is a patent issued May 18, 1875, to Francis Bell, Marshall, Texas. Bell's walking plow (see the Image Gallery) featured a thick, wooden moldboard with a series of deep holes drilled into the top edge. The moldboard was first soaked in oil, and then put back on the plow and the holes filled with oil. The oiled moldboard would, Bell said, "… allow the soil to slip over it, however sticky and waxy the soil may be, so that a furrow may be turned properly."

The lubricated moldboard was featured in several subsequent patents with both wooden and steel moldboard plows. One guy a couple of years later attached a reservoir to the back of a steel moldboard and drilled its face with small holes. He filled the reservoir with water and used a hand pump to "… supply water and air to the face of a moldboard to prevent the soil from adhering."

I'd love to hear the story of how this next method was first discovered. Someone found that the gumbo wouldn't stick to a heated moldboard. In March 1879, Argyle W. Tucker, Waxahachie, Texas, patented a plow with "a firebox, having a grate, a door and a draft-flue" attached to the rear of the moldboard. The idea was to build a fire in the firebox, "which heats the mold-board, which makes the earth slip more readily from the mold-board (making) the plow lighter of draft, and better work is accomplished."

A Texas man patented a "self-cleaning" plow in 1885 with a scraper on the face of the moldboard (see the Image Gallery). The scraper was on a shaft that went through the moldboard and was gear-driven by a wheel that ran in the furrow behind the share. As the wheel turned, the scraper rotated and supposedly loosened any dirt that had adhered to the moldboard.

In 1886, a Missouri man patented a wheeled, 1-bottom plow with a steam boiler perched on top (see the Image Gallery). Pipes carried steam to a "steam jacket" on the rear of the moldboard and the landside to keep them heated.

In 1887, a Pittsburgh man named James B. Oliver (not to be confused with the James Oliver who started Oliver Plow Works in South Bend, Ind.) improved upon the walking plow with the firebox.

Instead of a grate and chimney, Oliver installed a "vapor-burner" fed with liquid fuel piped from a tank between the plow handles (see the Image Gallery). He said his oil burner was a big improvement over the old firebox that "was troublesome … owing to the inconvenience of maintaining the fire (and) by reason of the trouble of disposing of the (ashes)."

As tractors became more numerous in 1920, William Ledbetter, Dallas, hit on the bright idea of using engine exhaust to heat the moldboards (see the Image Gallery). He wrote: "I am enabled to point the way to success in the project because of the present availability of unused heat arising from the extensive use of motor tractors for farming purposes." Ledbetter designed a box behind each moldboard and, using flexible pipes, ran the tractor exhaust into those boxes.

A year or two later, Ledbetter improved the heat jackets on the plow bottoms and the exhaust pipe connections to provide more flexibility between tractor and plow. In addition, he devised an alternative way to heat the moldboards electrically.

He envisioned a generator mounted on the tractor and driven by the engine "through any suitable … means such as gears or by a chain." The back surfaces of the moldboard and landside were provided with electrical resistance heating units connected to the generator by a heavy cable.

Ledbetter wrote that "in some cases it may be desirable to locate the electrical generator upon the tilling implement and in such a case the said generator is chain- or gear-driven from one of the ground wheels of the said implement."

A number of patents also relate to different methods of coating moldboards with an unlikely substance, such as plaster of Paris. One patent explains the process: "Experience has shown that when the discharging surface of the mold-board is made of plaster-of-Paris, such soils will not stick but will be freely shed from it. The moisture of the soil will enter the pores of the material composing the mold-board and lubricate the surface of the same, so that even the waxy gumbo soil of Texas will not clog or cake on it."

These patents all relate to different ways to apply a covering of plaster of Paris to a moldboard, or to methods of keeping it from drying out in use. Although I can find no mention of it in an old Moline catalog I have, one patent was issued in 1912 to the Moline Plow Co. for an economical and easily replaceable plaster of Paris moldboard (see the Image Gallery). It seems that the porous substance wore away rapidly and the heretofore permanently coated moldboards were expensive to replace. Moline proposed to make a separate plaster of Paris covering sturdy enough to ship and store, and could be easily applied by the user to an existing moldboard.

If you ever find an old plow with scraper, a firebox, or with a bunch of holes drilled into the moldboard, or with a strange plaster covering, you'll know what it is, and believe me, it'll be a real collectible. FC 

Sam Moore grew up on a farm in western Pennsylvania. He now lives in Salem, Ohio, and collects antique tractors, implements and related items. Contact Sam by e-mail at