Heard a guy at the supply yard say he never uses a power trowel on the first pass anymore

I was picking up some bags of cure and seal yesterday and this older finisher was talking to the counter guy. He said he switched back to a magnesium float for the first pass, even on big slabs, about a year ago. Said it gives him way better control to close up the surface before he even touches the power trowel. I tried it this morning on a garage floor pour, just a 24 by 24, and man, he was right. The surface was way more even when I finally brought the power trowel out. I didn't have to fight any low spots or overwork the cream. It felt slower at first but I think I actually saved time overall. Anyone else skip the power trowel for the initial finish?

3 comments

3 Comments

robert_lopez641mo ago

That old timer knows his stuff. Seen too many guys burn the surface right off the bat with a power trowel on wet cream. The magnesium float lets you feel the slab, find those soft spots by hand before you commit with the machine. It's like checking the oil before you just start tearing an engine apart. Saves you from creating more work later when you're fighting a wavy finish.

the_alice1mo agoTop Commenter

I get the "feel the slab" idea, but on a big pour time is everything. In my experience, a skilled operator with a power trowel on wet cream can cover ground and still read the surface just fine. Waiting to float everything by hand can let you fall behind the set.

ivan_mason1mo ago

My crew did a 40 yard warehouse floor last month and the power trowel first pass saved us two hours. @robert_lopez64, you can't hand float that scale and beat the clock.