poured-in-place concrete countertops
meathat
| Posted in Construction Techniques on
Greetings,
I’m on the finishing stage of my first poured-in-place countertop. The surface is now level, and I’ve worked up from 50 grit through 2000 grit wet diamond pads. The surface still seems a bit rough — feels like a 220 grit sandpaper. Is this the time to apply a penetrating sealer followed by beeswax to achieve a glossy finish, or should I run the wet sanding course again to achieve a smoother sheen?
Thanks for any thoughts.
Replies
After 2000 grit, or after 220 grit for that matter, the surface should feel very smooth. Something is wrong. How old is the concrete? Did you fill the surface voids? Did you use a fiber in the mix and could that be what you are feeling?
Waxing, sealing, spitting, crying, or cursing it now won't change anything.
You're probably not seeing how rough the surface is when changing pads. Each finer grit should remove the scratches of the pad before it, but they won't take down enough for two or three grits coarser. Drying the surface between grits will help show what's going on.
Beer was created so carpenters wouldn't rule the world.
I think you're right on. I ran the course uninterrupted, and the surface was never perfectly dry or free of grout slurry. Now that the surface is dry and clean, I can see it's pretty uniform, but probably needs to go from 500 to 1000 to 2000 all over again, although I'll stop to clean and dry the surface between each. Any thoughts on sealers/waxes? From what I can tell, the big guys (Buddy Rhodes, Cheng) lean toward penetrating sealers and beeswax. I'm hopeful the beeswax will give a bit more of a wet-look finish, since it's lightened up somewhat during the curing/finishing process.Thanks for your thoughts.Dan
When you look at sealers there are color enhansers that bring out the color to a wet look, some that don't change the color at all and many/most are inbetween. If possible a test square or two are good to cast to experiment on. I've done a lot of slate floors and helped with a set of concrete counters and it's really amazing to see the differences.
Also the gloss and build thickness varies all over the place. The build thickness will help hide grinding marks, although then it looks more plastic'ey and would be harder to touch up.
Beer was created so carpenters wouldn't rule the world.
Also, if you are grinding the surface it should be allowed to set up hard or the soft concrete will crumble off leaving a rough surface.
Beer was created so carpenters wouldn't rule the world.