• Here is the finished kitchen countertop main slab, installed and fully in use.

    Finished Countertop

    Finished Countertop

    I also know that some site visitors are looking for specific information about either installing new concrete countertops or working with some they already have. If you find what you’re looking for here, great. If you have any questions, feel free to drop me a quick note.

  • The night before last, I poured the bathroom countertop concrete. This was an interesting experience because I was pretty much flying blind with various ingredients.

    The colors were a little tricky to figure out for a few reasons. First of all, I was working in my garage with not the greatest indoor lighting and it was dark outside. Secondly, I was mixing brown coloring in with gray concrete (I think Buddy Rhodes uses a whiter “bone” color as a base, but it’s too much work to get around here) and trying not to make things too dark brown. Thirdly, finished concrete color is tough to guess at because it looks really dark when it’s wet, lighter but still dark when it’s cured, very much lighter when ground and dry, and finally it darkens again when it’s sealed/waxed. Lastly, I am trying for a somewhat multi-tone look on this countertop.

    I mentioned that I am using off-the-shelf concrete color that I picked up from Home Depot. I started out by dry mixing about a bag of concrete with about a quarter of a bag of mortar in a bucket. Then, I mixed up some color with some water and made a thick, almost crumbly mixture for my first step. I took handfuls of this mix and pressed it into the form, leaving some gaps. The pictures are dark, but here we are at this stage:

    Handfuls of doughy concrete mixture pressed into the form.

    Handfuls of doughy concrete mixture pressed into the form.

    A better angle, now with the wire reinforcing mesh added.

    A better angle, now with the wire reinforcing mesh added.

    If these look really brown, remember how black the kitchen countertops looked during this stage. I’m also going to be grinding this countertop down further, exposing more aggregate and thus natural stone colors.

    I mixed another batch of thinner concrete in a lighter shade and poured that on top of what was there. Then, I screeded it as well as I could and then ran a trowel over the surface. Finally I added the frame parts to make the skirt and filled in the gap with the mixture. Here is what it looked like after curing overnight.

    Cured overnight in this picture.

    Cured overnight.

    Alternate angle.

    Alternate angle.

    Last time, I let the countertops cure for four days before starting the grinding process. This time, I’m planning to wait at least five or six because of the mortar I added in. Plus I’ve made a slightly longer front skirt, so that could be slightly weaker. Since I plan to grind this down more into the aggregate, I’ve ordered a coarser grinding pad that should arrive shortly. I also ordered a new set of diamond grinding pads because I wore a few pads out on the last project.

    Updates probably next week when I remove the form and take a look.

  • The concrete kitchen countertops worked out so well I’ve been considering a concrete countertop for the bathroom. We’ve had a remodel planned and I kept in the back of my mind the idea that we may like the look of the concrete. As we did our planning, we decided on something of a rustic theme. Long story short, I ended up building the bathroom vanity myself so I could get just the right size we wanted and I think it makes sense to build a concrete countertop for it as well.

    In comparison to the kitchen countertop which included the huge 12-foot piece, this is a much easier project. This will be a single slab of approx 22 1/2″ x 44 1/2″.  I’ll be building a skirt to overhang the supporting plywood, but will not be making an upturned back edge this time.

    The sink is a bucket vessel sink, so it only needs a 1 1/2″ hole in the countertop for the drain. Add in the faucet along with the hot and cold controls and I will need four holes in the slab of 1 1/2″ in diameter. Should be more straightforward. If you’re new to visiting the site, this project should be a shorter set of steps to project completion.

    I’ve learned a few things from the last project and I’ve gotten a little braver this time with experimentation. I will be trying some off-the-shelf liquid concrete color from Home Depot, and I’m going to mix some mortar into the concrete to thin it out a little and reduce the aggregate quantity.

    Now for some pictures:

    Form building started with the front edge fastened on.

    Form building started with the front edge fastened on.

    Quickrete Liquid Cement Color. I'm trying for a final tan color so I thought I might be able to use just a little brown. Some experimentation so far looks promising.

    Quickrete Liquid Cement Color. I'm trying for a final dark tan color so I thought I might be able to use just a little brown. Some experimentation so far looks promising.

    Quickrete 5000 commercial grade concrete. Same as I used before for the kitchen countertops.

    Quickrete 5000 commercial grade concrete. Same as I used before for the kitchen countertops.

    Quickrete commercial grade mason mix. This is the mortar I plan to mix into the concrete a little to thin out the aggregate. I'm nearly certain that I'll be violating some rules of concrete and experts would counsel against it, but I can sacrifice strength for workability here.

    Quickrete commercial grade mason mix. This is the mortar I plan to mix into the concrete a little to thin out the aggregate. I'm nearly certain that I'll be violating some rules of concrete and experts would counsel against it, but I can sacrifice strength for workability here.

    Form sides attached. This came together pretty quickly.

    Form sides attached. This came together pretty quickly.

    If you're interested, these are the self-drilling screws I have used to fasten the form together. They work really well in my opinion, especially for 3/4

    If you're interested, these are the self-drilling screws I have used to fasten the form together. They work really well in my opinion, especially for 3/4

    This is the extent of my sink and faucet knockouts. I'm liking the vessel sink idea more and more. :)

    This is the extent of my sink and faucet knockouts. I'm liking the vessel sink idea more and more. :)

    The copper bucket vessel sink. Yes, the handle really works. I'm looking forward to installing this: adhesive on the bottom and then drop it into place.

    The copper bucket vessel sink. Yes, the handle really works. I'm looking forward to installing this: adhesive on the bottom and then drop it into place.

    I had to make sure I had enough clearance for the faucet spout and plumbing.

    I had to make sure I had enough clearance for the faucet spout and plumbing.

    Wire reinforcement. Two offset layers of mesh just like on the kitchen countertops.

    Wire reinforcement. Two offset layers of mesh just like on the kitchen countertops.

    Contrasting color (black) 100% silicone used to seal up the edges.

    Contrasting color (black) 100% silicone used to seal up the edges.

    This form came together quite quickly. I should be able to pour the concrete sometime over the next few days.

  • I wanted to mention some things about the tools that I used, since a lot of people are looking for some direction on what grinder to use for this wet grinding and where to get diamond grinding pads.

    First, I used a Secco Wet Grinder (picture below) that I ordered from BargainBlade.com. It’s probably a lower-end grinder since it’s only about $160, but it’s a variable speed grinder with a built-in water feed and GFI. It worked just find for my hours and hours of grinding and the only issue I had with it was the switch lock mechanism seemed to get a little gunked up with grinding dust and the switch wouldn’t say in the “on” position until I cleaned it out. I had to fuss with the switch a few times during the project and that was it.

    The wet grinder

    The wet grinder

    Diamond grinding/polishing pads are expensive and generally seem to run about $20 per pad. Just for a basic matte finish, you probably need four or five different grits so you’re already over $100 just in grinding pads. If you order a Secco wet grinder, you can buy a kit which comes with seven different 4″ pads of varying grits for an additional $30 or so and it’s probably worth it to buy the kit if you’re buying a grinder. (I’ve since discovered that toolocity.com has some diamond pads for very reasonable prices. I’ve not ordered from them, but I’d consider it if I need some more pads in the future.)

    For my project, I also bought the ground+matte finishing kit from Cheng Concrete. I figured since it was the first time I made a concrete countertop, I’d buy the finishing kit from the experts. The grinding pads are 5″, so they are larger and theoretically should speed up the grinding/polishing process. I found the pads wobbly, whether from the polishing pad holder or the pads themselves, I wasn’t sure, but it wasn’t as smooth a grind as the 4″ pads which cost me all of 30 extra dollars for seven different pad grits. Still, the coarse 5″ pad was nice to have for the grinding portion, so I have mixed feelings about the finishing kit.

    To me, the best things about the finishing kit were the polishing pad and the wax. It made things much easier to already have the polishing supplies on hand. If I did a project like this again, though, I’d probably pick and choose individual items, since Cheng Concrete seems to charge a bit of a premium for their supplies and I wasn’t overly impressed with the diamond pads.

    Tags: , , ,

  • When we left off, I was thinking about the next step after a layer of red slurry followed by a layer of charcoal slurry didn’t leave much red to be seen.

    I decided to break out the last small box of red slurry and throw another top coat on there. This time I used a grout float (highly recommended) and let the slurry dry for one day. Then I polished the entire thing down. This last grind/polish took a long time because I really wanted to get everything finished properly. I don’t know exactly how long it took, but I probably ran the grinder for four or five hours straight using various grinding pads to grind off all of the excess slurry left on.

    Final coat of red slurry

    Final coat of red slurry

    It was more important to me to fill the voids thoroughly than to scrape off as much slurry as possible during application. I had more to grind down doing this, but it wasn’t too hard since I only let it cure for one day.

    Lots of excess slurry to grind down

    Lots of excess slurry to grind down

    Before the final grind, the slabs looked almost solid red

    Before the final grind, the slabs looked almost solid red

    Here’s the small section, starting to dry after the final polish.

    After grinding, though, they looked great

    After grinding, though, they looked great

    Large slab, still wet after the final polish

    Large slab, still wet after the final polish

    After I was done with the final grinding/polishing, I sealed them with concrete countertop sealer, which seems similar to tile or grout sealer. Maybe it’s the same, I don’t know, but I used the “official” stuff. I was up far too late doing all of this, but one thing leads to another and I really wanted to get the sealer on there so it could cure for a day or two.

    The day after, my brother came over to help dry-fit, finish grind, and install these things. The slabs were surprisingly easy to install; each section maybe weighed 200-250lbs which were pretty easy to carry in and lay carefully on top of the plywood base we put down over the cabinets. After dry-fitting the slabs, we had a little finish grinding to do on the bottom (high spot here, rough spot there, etc.). We finally shimmed the slabs as necessary to keep them level and match up the sections.

    The following pictures are NOT the final product. They are the slabs installed and fit together with silicone sealing the joints between the main slabs. They have since been cleaned and waxed (like you would wax a car, with a can of wax and a sheepskin buffing tool) and the sink has been installed. This has happened around the Thanksgiving holiday, so those pictures will be coming at some point soon. At any rate, here’s a glimpse of what the final product looks like installed.

    Main countertop installed

    Main countertop installed

    Slightly different angle

    Slightly different angle

    The camera doesn’t effectively convey the impressiveness of the 2-1/4″ thick front face of the solid concrete countertops, but the surface is quite smooth and will probably win in a fight between it and most dishes you might have around the kitchen.

    An attempt at a closer look at the surface

    An attempt at a closer look at the surface

    The surface is nicely consistent but at the same time very unique

    The surface is nicely consistent but at the same time very unique

    I have to admit, these countertops are cool. I love ’em. So does everyone else who has seen them. Not only are they are something of a labor of love, but they’re impressive conversation pieces right in the kitchen and you polish them with a car waxer! How manly is it to go to your local auto parts store to buy the right pads to maintain your kitchen counter?! Oh, and no one has the exact same piece in their home.

    The final waxed product is only slightly smoother, and of course cleaner (the pics above still have some concrete dust left on them from installation). I’ll post those pictures when I can, but I’m already thinking about other ways I can use concrete for various home projects…