ADDING TRACTION. A spot of hardfacing is added to the heel of a horseshoe with a welding torch. Note the two spots of hardfacing already applied to the toe of the shoe.
Like Kleenex for facial tissues or Band-Aids for adhesive bandages, Borium and Drill Tech are brand names so widely recognized that they have become generic terms for the hardfacing products used by farriers. That could confuse any discussion of hardfacing products and their application.
Don’t be misled. There are a handful of brands, all of which use particles of super-hard tungsten encased in a softer metal shaped into a rod. The softer metal is welded onto the shoe, holding the exposed tungsten particles in place to provide traction and lessen wear on the shoe.
Picking the right hardfacing product depends on two important considerations:
- Do you want to put hardfacing on a horseshoe with welding equipment, or would you rather be able to braze the material onto a shoe with a forge or heating torch?
- Are you more concerned about adding traction to the shoe or extending its useable life?
Having answered these questions, you can begin considering the available options, which fall into two categories:
H Hardfacing in which the tungsten carbide particles are encased in a mostly steel matrix. These products, often called tubed metal, must be welded to the shoe. This requires, of course, that the farrier have welding equipment and the skills to use it. The products include Borium, made by the Stoody Division of Thermadyne Co., Wear-Trac from Hartwell Industries and E-Bor from Amsterdam Blacksmith Supply.
BORIUM AT WORK. This old shoe from a Clydesdale features three spots of Borium on the toe, rather than the usual two spots or a narrow strip, due to the large size of the hoof.
H Hardfacing in which the tungsten carbide particles are encased in metals such as nickel, copper or brass. These metals melt at lower temperatures than steel and thus can be attached to the shoe with a forge or heating torch. These products, sometimes referred to as composite rods, include Drill Tech, CarBraze from Hartwell, and EME from Amsterdam Blacksmith Supply.
The tubed metals and composite rods, which look very much alike, come in different diameters, from about 1/8-inch to 3/8-inch, and usually from 12 to 14 inches in length. The wider the rod or tube, the more volume of hardfacing applied to the shoe. The traction provided by the hardfacing depends in large part on the volume and height to which it is applied, as measured from the ground surface of the shoe.
However, some products also are marketed as coarse, medium, fine and extra-fine, depending on the size of the tungsten particles. The standard measure of the size of the tungsten particles is the so-called “mesh,” with a small mesh indicating bigger particles (a 4 or 6 mesh for coarse particles) and a bigger mesh number for smaller particles (up to a 16 mesh for extra-fine particles). Meshes up to 40 are available for non-shoeing, industrial use.
The larger the tungsten particles, the more traction or “bite” provided. The smaller the particles, the less traction provided. Thus, the fine and extra-fine hardfacings are often used to reduce shoe wear rather than add traction.
Lee Green, an International Hall Of Fame farrier and owner of The Shoein’ Shop supply store in Yucaipa, Calif., says the coarse product should be used for big horses that need extra traction, while the fine is good for saddlehorses to add wear to the shoe.
“The extra fine is not much more than a powder,” Green says. “When it’s powdered, it doesn’t have the biting qualities and it will be slick. If all you want is to protect the shoe, then use the extra fine.”
A BETTER BOND. Adding flux, either in powdered form (above) or as part of the hardfacing rod, to the welding or brazing joint keeps oxygen and the resulting impurities from hampering the bond between metals.
He says hardfacing is commonly used to provide traction for horses used on pavement. The usual placement of the hardfacing includes a spot on each heel and a narrow strip across the toe, he adds.
Green notes that the welding method used with the steel and tungsten mixtures requires the farrier to melt, or “puddle,” part of the shoe so it can mix with the melted steel of the tubed metal. “It’s been done forever,” he says. “It’s a good way to attach the shoe and the hardfacing, but it’s the hard way.”
Green recommends that farriers who are not experienced welders choose hardfacing products that mix tungsten with nickel, copper and brass alloys that are softer than steel. These alloys melt at lower temperatures, so they can be brazed to the shoe
“It can be done quickly, and you can use a forge or a torch,” he notes.
The Brazing Process
Green advises using EME, a composite rod product that allows the farrier to break off a piece the size that he or she wants to place on the shoe. The piece of EME is set aside while the shoe is heated above a dull red in the forge or with a heating torch.
When the shoe is hot, slag will appear on the surface. The slag, a collection of impurities in the metal, creates a barrier between the shoe metal and the tungsten mixture if not removed.
“You have to get rid of that slag. That’s extremely important,” Green says. He recommends quickly wire brushing the hot shoe to remove the slag.
Even with the slag removed, the bond between the shoe and the hardfacing can be weakened by oxidization, the impurities formed by metal exposed to oxygen during the brazing or welding process. Flux, a chemical compound that keeps oxygen away from the joint, is included in many hardfacing products.
However, Green says, “I would always add flux. The best flux for this kind of brazing is 20 Mule Team Borax, the powdered soap from the grocery store. It’s made of the same stuff as the commercial fluxes. A lot of people use it for forge welding.”
Some fluxes contain small metal particles to help adhere the metals, “but you don’t want that in this process,” he notes.
READY TO NAIL. Set aside to cool after the hardfacing is applied, this shoe is ready to help a horse keep its feet on slick surfaces.
Green suggests spreading a half-teaspoon to just a pinch of Borax, depending on the size of tungsten/alloy mixture being put on the shoe, directly on the area being heated. Then immediately place the piece of hardfacing on the hot spot, he says, and carefully put the shoe back in the forge or resume heating it with a torch.
“The metal around the tungsten will melt and drop onto the shoe, and you’re finished,” he says.
Green notes that while the shoe is still hot and before the piece of tungsten/alloy mixture sets, “you can move it around on the shoe with a pritchel or some other tool to put it exactly where you want it. You can stack it up or flatten it out. You’ve got a few seconds to work with it.”
The hardfacing “spot” attached to the shoe can sometimes be reused later. “You can heat an old shoe and remove the tungsten and alloy if it’s not too worn. Just reheat it and slide it onto the next shoe,” Green says.
The ability to reheat a used shoe to move the tungsten and alloy can be useful in doing resets, he notes, and, “That would be extremely beneficial on Saddlebred shoes, for instance, where a farrier might use the same shoes for a year.”
As for charging customers for hardfacing work, Green says farriers should add the cost of the materials used and the time taken to do the work, which is typically about a third of the cost of a regular shoeing job.