definitive guide to concrete countertop?

[Gulf]

Marble is what I was thinking. I don't know why I typed limestone? You are bringing up a great point for anyone thinking about concrete polishing. It can get real messy. I elevate my projects to relieve my back. Depending on the time of year, a full rain suit and face shield is a must for me. My "oldometer" is at 61 .

[david s]

David,

That counter is looking great!............. Is that crushed limestone that you are using in the upside down pour?..............Your pics are killing my old back .......... When you get my age, you will appreciate the word "ergonomics" .

I used marble chips, some mystery decorative rocks and some leftover random rock tiles.It looks like the stars in a night sky. That's the idea anyhow. I agree that the working position is poor, but that slab weighs 40 kg, not too easy to lift on my own. Also the water that splatters off the polisher makes less mess at ground level. Hence the downpipes used as a fence in last pic. Joe, I think I'm probably older than you anyhow. My odometer says 67 what's yours?

[Gulf]

David,

That counter is looking great!............. Is that crushed limestone that you are using in the upside down pour?..............Your pics are killing my old back .......... When you get my age, you will appreciate the word "ergonomics" .

[david s]

I got mine from eBay. There are four things that you really need. A water feed from the centre of the disc. a variable speed control, removable diamond pads and a decent electrical cutout, all of which came with the machine I bought. I first started with and orbital sander fitted with wet and dry paper and using manual water feed from a hose. It worked but was painfully slow. The other pics here show a panel I'm currently working on. So far polished down to 100. Gulf has done some very nice work and may point you to other threads about this craft.

[UtahBeehiver]

I used a Hardin VSP5 stone/concrete polisher GFCI protected uses 5" diamond pads. It is not a cheap tool, in the $200 range without the pads. Could of made ya a deal, peel and polisher, just kidding.

[cnegrelli]

This seems like a good place to post this due to the title, despite the thread not being active recently.

Is there a good wet polishing tool people have found? From reading, it seems like a wet polisher with variable speed control is ideal. I'm not finding anything online at HF for example.

[CoyoteVB]

Re: definitive guide to concrete countertop?

Hi Rich-

i also cast in place because of the size. I uses 2:My bad. I did you metal lath as well. On the first counter top I did not anchor the mesh and it floated to the surface. On the main counter top I pours the 1/2 the concrete and then placed the lathe. I used stucco nails to keep it from floating to the surface. You can buy diamond pads on Amazon.com such as STADEA Premium Grade Wet 4" Diamond Polishing Pads Set + Rubber Backer For GRANITE MARBLE STONE - Amazon.com This is just one seller. I just started used the pads in the kit. I polished all the way to 3,000 grit and then realized the sealer recommended only going to 800 grit. So, I re-sanded back to 800 grit. When buying diamond pads there are both dry and wet options. There are also a variety of dyes. I chose a charcoal that I added to the concrete as I mixed it. When polished, the cement was black but the sand and stones were polished.

Brian

[RichC]

Re: definitive guide to concrete countertop?

I built my entire outdoor kitchen with concrete countertops. Here is my input. Mix concrete with polyester or stainless fibers. Pour the concrete into your forms. Vibrate to remove air bubbles an to get the slurry give you that shiny look on the edges of your forms. Pull forms, cover with plastic an slow cure with water. At least a week, the longer the better to gain strength and minimize cracks. If you have pits, fill with a mixture of fine sand and cement. If you want a granite look polish with diamond pads. Start with 60g grit and go down to 800 grit. seal with a poly urethane sealer.

Thanks Coyote, I'll be doing a variation of that because I'll be casting in place. Do you not bother with steel mesh? just fibres?
When you say 'slow cure with water' In my climate that just means let it dry naturally, particularly as I'll be doing it late autumn/early winter.
Also, when going from 60~800grit, what are the increments? I'm not sure what pads to buy?

Thanks

R

[CoyoteVB]

Re: definitive guide to concrete countertop?

I forgot to mention..mix the concrete dry and plan on working up a sweat to trowel the slurry to the surface.

[CoyoteVB]

Re: definitive guide to concrete countertop?

I built my entire outdoor kitchen with concrete countertops. Here is my input. Mix concrete with polyester or stainless fibers. Pour the concrete into your forms. Vibrate to remove air bubbles an to get the slurry give you that shiny look on the edges of your forms. Pull forms, cover with plastic an slow cure with water. At least a week, the longer the better to gain strength and minimize cracks. If you have pits, fill with a mixture of fine sand and cement. If you want a granite look polish with diamond pads. Start with 60g grit and go down to 800 grit. seal with a poly urethane sealer.

[RichC]

Re: definitive guide to concrete countertop?

Thanks Guys, ATK they're great links, thx again

[ATK406]

Re: definitive guide to concrete countertop?

Sorry, let me try that link again, the blog posts are more informative;
cast in place | Concrete Countertops Blog

[ATK406]

Re: definitive guide to concrete countertop?

Use of a Superplasticizer and/or Pozzoloans will help to make your mixture design easier to place - but they are a little expensive (much less than the premixed countertop mix though). Due to the relatively thin cross section of the countertop and the fact that it may be used to span an unsupported opening, every effort should be made to make your concrete as strong as possible. I.E. Low water to cement ratio, well graded aggregate (fine, medium and course), reinforcement (pencil thin rebar or mesh) and the use of admixtures if you want to go the extra mile. Here is another good link for both GFRC and Cast concrete countertops - Concrete countertop training : Concrete Countertops, Institute, Concrete Connections, Raleigh, NC : The Concrete Countertop Institute.

Regards,
AT

[RichC]

Re: definitive guide to concrete countertop?

There is a link on Lburou's Forno Bravo Treasure Archives in the Newbie Section that has hyperlinks to several builds with various concrete counter projects

Thanks Russel, I had seen that before but coudl never find it again. Added to favourites!

[UtahBeehiver]

Re: definitive guide to concrete countertop?

There is a link on Lburou's Forno Bravo Treasure Archives in the Newbie Section that has hyperlinks to several builds with various concrete counter projects