My switch from a magnesium to a magnesium-aluminum float for big slabs

For years, I only used a standard magnesium float on any slab over 500 square feet. About two years ago, a buddy on a job in Tempe let me try his magnesium-aluminum combo float. The difference was huge. The aluminum strips cut through the wet concrete way easier, saving my arms on those long pulls. I bought a 48-inch model the next week and haven't looked back. It just glides and leaves a much tighter finish with less effort. Has anyone else made this switch, and what size do you prefer for driveways?

3 comments

3 Comments

victorhill23d ago

Totally get that. I started using a 42-inch mag-alum on garage floors and it's a game changer for the initial bull float pass. The weight distribution just seems to knock down the aggregate without digging in like a full mag can on really wet mix. I still keep a pure magnesium handy for the final pass before edging, feels like it gives a bit more texture for the broom finish.

the_paul23d ago

Yeah the "knock down the aggregate without digging in" part is so true. I've seen guys wreck a fresh pour by being too heavy handed early on. That mag-alum combo just seems to glide over the top. And keeping the pure mag for the end makes sense, it's like you need that tiny bit more bite to set up the surface right for the broom. Smart way to work it.

the_susan23d ago

That combo float is a total arm saver on big pours. I mean, the first time I used one it felt like cheating compared to dragging a full mag. For driveways, a 42-inch hits the sweet spot for me, lets you cover ground but still handle the turns. You gotta watch the leading edge on the second pass though, it can dig in if the mix starts to set up a little.