It's All In The Mix

Concrete begins its life in a mixer. Supplying an easy-to-use, well-maintained mixer to customers placing concrete is an important task.

Frequently used for small non-commercial jobs where small batches are required and productivity is not necessarily an issue, portable concrete mixers from 3 to 5 cubic feet are typically considered "homeowner" mixers. But they're also favored by small general contractors, landscape contractors, masons, concrete construction and/or repair contractors and even farmers, who use them for mixing feed and grain.

Those same users who are looking for more productivity can find it with larger portable mixers ranging from 6 to 9 cubic feet. According to Warren Faler, mixer product manager with Multiquip, 9-cubic-foot units are the most popular for rental because they'll always meet a contractor's demand, no matter how big the job.

In addition to mixing concrete, applications for portable mixers include mixing mortar, stucco and grout for patching jobs, residential sidewalks, building brick, block or stone walls or wherever a pad of concrete is required.

"The versatility of a mixer makes it a cost-effective purchase, particularly when, with proper maintenance, these units will last for years," says Faler.

Selection considerations

"Rental businesses always want a return on their investment and low maintenance designs when choosing any kind of equipment," says Frank Wenzel, vice president of engineering at Stone Construction Equipment.

When it comes to portable mixers, ease of getting the unit around shouldn't equal shoddy construction. Concrete weighs about 125 pounds per cubic foot, so a strong frame is critical. Quality design and materials are a must, say sources.

Wenzel notes that components such as the paddle shaft and seal are high wear items. Some manufacturers, like Stone, offer lifetime warranties on these components.

The working end of a mixer - which includes the paddle shaft and drum - is the most important component. "Look for a strong paddle shaft and a thicker drum," says Wenzel.

Most manufacturers offer steel and polyethy-lene drums to fit individual user preferences. There can be minor differences in steel and poly drum width and depth, but they're generally the same in terms of size and shape.

"Steel drums are more durable, but cleaning can often be tedious with denting and other damage to the drum a possibility," says Faler. "Poly drums, which resist rust, can be cleaned in minutes by simply tapping with a rubber mallet."

Wenzel notes that when choosing the type of drum, user preference is key. But so is the type of material being used in the drum.

"Materials vary depending on where in the country you are," says Wenzel. "And depending on the material, the wear on the drum is different."

Some mixer manufacturers, like Stone, offer drum kits to easily interchange drum types. "Some users prefer the easy clean up of poly," says Wenzel. "Others like the straightforward steel drum. It depends on their experiences and preferences." With a drum kit, you're ready with either type.

Portable mixers offer various types of power systems, including electric and gasoline options. Single-phase electric motors are available in the 1/2 to 1 1/2-hp range, while gas engines span from 3 to 13 hp.

"About 95 percent of the mixers on the market are gas-powered because they're more portable," says Faler. "Electric mixers require an electric power source be nearby, which is often inconvenient. These mixers are used primarily in stationary locations such as factories. But electric-powered mixers, in contrast to gas models, do not emit fumes and are preferred by some contractors."

As with the construction of the unit, durability is key with its power source. According to Nicholas Taylor of Belle Group Inc., their electric motors are double insulated, which is important when working in close proximity to water with a metal frame.

Maintaining mixers