Intrigued by the idea of concrete counter tops, I borrowed from a number of techniques found on the web to come up with this vanity which would technically be called a concrete overly. The vanity also served as the testing grounds for a much larger project I will be doing next spring, a 3 foot by 13 foot concrete outdoor kitchen counter. So even though the time, effort and money needed to fabricate this rather tiny counter top may seem out of the proportion to the final product, it was a great learning experience and the techniques might be useful to others who want to scale them up to a larger size project.
Materials you will need include:
* Enough 3/4" Medium Density Fiberboard (MDF) for the counter top and edges
* Enough fortified (with polymers) VersaBond thin set for your project
I used less than 1/8th of a 50 lb. bag for this 2 sq. ft. project
* Enough non-sanded tile grout for your project.
I used less than 1/8 of a 10 lb box for this project
* One sheet of metal stucco lath (this project used about 1/5 of a sheet)
* Small amounts of latex and acrylic paint if you want marble or granite effects
* Envirotex Lite epoxy “bar coat”. (4 oz covers 1 square foot so you can purchase a “kit”
Appropriately sized to your project)
* Screws, staples, nails, carpenters glue
* Rubber “Bondo spreaders” and steel drywall knife/joint knife
* Sandpaper (50 to 400 grit)
Step 1: Constructing the Wood Core.
If you have exposed corners on your counter top, cut them at a 45 degree angle. Then sand the corner into a smooth curve. It will speed the sanding if you use some sort of electric or air sander such as the orbital air sander used for this project. But it can be done by hand if necessary.
The top edge of the counter can remain square or you can give it a gentle curve using sand paper or a router as shown in the photo. When completed, your wood core should look something like the final photo.
Step 2: Apply the Stucco Mesh.
Make small pie cuts in each exposed corner and bend the mesh tightly down around the curved edges of the core. Trim the material in the corners wherever it might over lap. You want all the lath to lay as flat as possible against the wood core. Bend the mesh around the bottom edge and staple to the bottom. Use a hammer to pound down any proud staples. The completed wire mesh should look something like the final photo.
Step 3: Apply the Thin Set Concrete.
Apply the first coat of thin set using the mesh as a thickness guide. Try to push the mortar down into the mesh as much as possible and then level things off at the top of the mesh. Don’t get too fussy about smoothness with the first coat. You are basically just trying to fill in the wire mesh with concrete.
Step 4: Removing the Rough Spots.
Apply the second coat of thin set. The goal for this coat is to get about 1/16th” to 1/8" of mortar above the stucco lath. If you created rounded edges, you can get those fairly smooth by simply using typing paper cut into a small rectangle. Apply a fairly heavy coat of mortar to the entire length of the edge and then, beginning at one end of the workpiece, wrap the paper around the contour of the curve as shown in the photo and pull the paper to the other end of the workpiece. With just a little practice you will get a feel for how much pressure to apply and how quickly to move the paper. You will also learn to hold the paper so the edges to not drag in the surrounding wet mortar. Mylar also works well for this task but the plain paper will do in a pinch. Don’t be too concerned if you leave a small line or ridge on each side of the paper as you are pulling. This can be sanded off when it is dry. The photo was taken after the edge was dry simply to demonstrate how the paper is formed and held while it is being pulled down the edge.
When the thin set is dry, sand with 50 grit paper to knock off the high spots, nubbers and trowel lines. Apply a final coat of thin set taking care this time to get the surface as smooth as you can. Your goal now is to get a fairly smooth surface at a uniform height.
Step 5: Apply the Grout "color" Layer.
To smooth the curved edged of the grout layer I fashioned a forming tool from a small piece of roof flashing. The tool is bent to the rough shape of the curved edge as shown in the photo. Apply an ample coat of grout to the entire edge and then pull the tool from one end of the workpiece to the other going right around any curved exposed corners you might have. It will take a couple practice runs to get the feel of the technique. Don't worry if you leave small lines or ridges in the wet grout. You can come back when it is dry and fill the low spots and sand off any high spots.
When the grout is dry (usually over night) block sand with 120 grit paper. The curved edges can be sanded with a fine grit foam backed sanding pad available from Ace Hardware or other vendors.
After sanding apply a second coat of grout. Then sand again when dry. Keep applying coats of grout until you no longer see any of the gray thin set layer of concrete peeking through the sanded grout. I had to apply three layers. You may require more or less depending on your particular project. When you no longer see the thin set, block sand one final time with 240 grit and then 400 grit paper. Your results should look something like the final two photos.
Step 6: Special Effects.
For this I project I used Kilz white latex primer as my “base” simply because that is what I had on hand. I thinned the base with water and then added Apple Barrel acrylic paints (Wal Mart hobby section) to tint and shade the color. The paint was applied using torn pieces of typing paper which are dipped in the paint and then dabbed and dragged across the workpiece to create a vein effect. The cloudy/misty areas are created by applying a bit of paint and then whisking with a soft brush over the top in multiple directions, much like an umpire dusting off home plate. If you make a mistake, don’t worry. Simply apply more paint over the top until you begin to see an effect that looks right to you.
When you are satisfied with your marble/granite/stone effects and all the paint is dry, apply the top coat of Envirotex Lite epoxy. This epoxy is commonly call “bar top” and provides a thick glossy and self leveling protective coat on the surface of the counter. Just follow the directions that come with the product. Be aware that Envirotex is not UV resistant and should not be used where sun exposure will be an issue. Also, do not use it where hot pots and pans might come in direct contact. It can be used for kitchen counters, but always have suitable tiles or potholders available for setting down hot objects. Also, don’t cut directly on the counter. Use a cutting board.
Step 7: Installing the Vanity.
The cost of doing this vanity top is very difficult to estimate since the amount of each material used was quite small and I had a number of the items already laying around from previous projects. I am, however, budgeting roughly $200 for the 3' x 13' counter I will be doing in a couple months which will give you some idea of what a larger project might cost when using this method of fabrication. Hopefully I will be able to post up an Instructable with an exact cost breakdown of that project when it is completed.