Fine Grind

How to churn mud and almost hit everything.

Today the floor slab grinding & polishing guys arrived.

We are very, very excited (and a little nervous) to see the end result.


The visit started with equipment arriving.

First a large generator to power the equipment.  Apparently they bring their own power to make sure they have all they need.  These machines have some big motors.

Then the trailer with all the grinding machines.  Quite a bit of time was spent trying to back the trailer up to the folding doors so that they could roll the machines directly out onto the slab.  This is the final result...pretty close, but not quite enough.  And this guy was an amazing driver - we needed about 1 more foot to make the turn.

I suffered a series of minor heart attacks as he came oh-so-close to just about everything.

This is the droid we are looking for.

The machines are quite heavy.  This is the small machine, at about 400 pounds.

The big machine, which they had hoped to use, was left in the trailer because it weighed too much to carry into the house.  Roll-off or nothing.

Not shown - large vaccuum system, multiple large polishers, and hand grinders & polishers.

"Before" picture.

Here is a picture showing the slab prior to any work, for the record.

Joint Filling

First order of business (besides all my pre-cleaning) is to fill the saw-cut expansion joints with polyurea, a semi-rigid joint filler.

This is allowed to partially cure, then the top of the over-filled joint is shaved off with a razor-scraper.  What remains will cure completely and be ground down along with the slab.

Next they work around the perimeter with a hand grinder to get into corners, and close to walls where the big machines don't reach.

Then the big machine starts grinding.  They tested a few grits and decided to start with a 40 grit metal.  This does the bulk cutting, and then they progressively use finer and finer grits up to 400, where we stopped.  It can be taken much farther for a mirror finish, but be opted not to go that far.

Finally they mop on a penetrating densifier, and buff it in, followed by a penetrating sealer, also buffed in.  The final result will be shiny, durable, and stain resistant.

A lot depends on the skill of the concrete guys that placed the slab...we are holding our breath to see how it turns out.

Upper Slab (Kitchen), Before