Which Portable Mixer is Right for Concrete Countertops?

Question: I want to buy a portable mixer for making concrete countertops, but I'm confused by the different types available. Which type works best for countertop mixes?

Answer: It's best to match the type of mixer to the type of concrete you plan on using when making countertops. There are three basic types of concrete mixers available: drum, mortar, and vertical shaft. Here are basic descriptions of how each mixer type works and what concrete mixtures they are best suited for:

Drum mixers are the most commonly used type and what most people picture when they think of a concrete mixer. Drum mixers are designed to mix relatively fluid concrete that contains significant quantities of large aggregate. Typically very stiff low-slump, no-slump, and all-sand mixes are difficult to mix in a drum mixer because they tend to stick to the walls of the drum and not tumble and churn.
Mortar mixers, sometimes called stucco mixers, have a horizontal shaft with paddles attached. Thorough, efficient mixing depends on the mixing action of the paddles and not so much on the concrete mixture's physical characteristics. For this reason, mortar mixers tend to be more versatile than drum mixers because they can mix both highly fluid and very stiff concrete mixes. And they can usually handle concrete with up to 3/8-inch aggregate.
Vertical-shaft mixers have wide, shallow, circular mixing pans and are similar to mortar mixers in that the pan remains stationary. These mixers are less common than the previous two types, but they offer increased mixing speed and efficiency and are capable of mixing most types of concrete, both stiff and fluid. The drawback is the discharge method, which may make stiff mixes more difficult to deal with.

Sincerely,

Jim Peterson

The Concrete Network