Concrete Countertop Tool Videos

Cheng uses door skin strips that are available at home improvement centers. This material is then cut to the appropriate length using a mat knife (box cutter) or a small table saw. On the jobsite, lay out the strips along all of the walls the countertop will be placed against. Cut the strips to the proper length making sure the strips connect in each of the corners. The strips can be fused together using a hot glue gun.

This is an inexpensive way to measure the space for a concrete countertop. It's important not to just measure with a measuring tape because the walls in most homes are not straight. For this reason, using the door skin strips will follow the edge of the wall perfectly and ensure that the countertop will fight tightly against the wall during final installation.

Remember, the size of the mixer (the one given by the manufacturer), is not how much concrete material it will mix. The manufacturer is providing the entire capacity of the mixing drum. In a 14 cubic foot mixer for example the most material that should be mixed is 10 cubic feet. This would be approximately 18 fifty-pound bags of concrete mix. With at 3 cubic foot mixer it is safe to only mix about 2 bags per batch.

When renting or buying a concrete or cement mixer, consider using a gas-powered mixer. These can be used on jobsites without any power. Make sure that the gas-powered mixer is not used indoors. The fumes from the gasoline need to be vented properly. When mixing indoors due to space requirements or weather, be sure to use an electric concrete mixing machine.

Be safe when using any concrete mixers. Do not stick your hands or head inside the moving drum. Make sure clothing items cannot get caught in the mixing drum. Be sure to wear the proper eye protection, respirator, and gloves as concrete dust can be detrimental to a person's health. Concrete is a caustic material and will burn the skin if not properly protected.

Before starting the mixer, place the mix and any admixtures that may be needed inside the mixing drum. Then start the mixer and slowly add the specific amount of water recommended by the mix manufacturer. Be sure to mix the concrete long enough so that all the aggregate, fiber, color, water, etc. are thoroughly mixed together.

Melamine is a particle board that has been treated with a plastic coating on both sides. This material is reusable, cheap, and it's available at any home improvement center.

When the mold is removed from the concrete countertop, the surface will reflect whatever imperfections may have been present in the mold. For this reason melamine is used because it is a clean and smooth surface and leaves fewer imperfections than other concrete forming materials like wood (which leaves the impression of the wood grain).

In addition, melamine is useful because you don't need 30 years experience troweling concrete to get a nice concrete countertop finish-the melamine does the work for you.

Cheng often augments the edges of countertop with unique designs. He uses polyurethane rubber to make these custom molds. This is a two-part compound that you mix right before making the mold. When dry, this liquid forms a hard rubber of varying flexibility.

For example, Cheng created a mold from an egg and dart pattern that was originally on a Victorian wood molding. To make a mold of this pattern, simply build a box to the width and length desired with the original wood molding face-up in the mold. Mix the two-part compound. Then spray the inside of the mold with the manufacturer recommended release agent and pour the liquid rubber into the mold.

Make sure that stray hairs or dust are kept out of the mold as every little detail will be reproduced in the rubber mold that is made. Cheng uses a variety of original Chinese carvings and geometric moldings to make one-of-a-kind rubber molds.

Mold rubber can also be a great tool for making integral sink molds. In this situation, you have to make the original out of foam. Then the sink mold that is made out of foam can be reproduced in the polyurethane rubber that will last much longer.

One of the fundamental parts of concrete countertop making is the mold. Once the mold is made it is important that the edges and corners are rounded. To avoid having to go back and grind the concrete countertop edges after it has been cured, Cheng uses 100% silicone caulk inside the edges of the mold.

The caulk is applied before any material is placed inside the mold. This material is available at any local home improvement center. The reason Cheng recommends only using 100% silicone caulk as opposed to other types of caulk, like poly-butylene or acrylic, is that these leak water and material. The 100% silicone caulk will form a water-tight edge surrounding the mold.

After the mold is complete, start by applying the caulk to the corners of the mold and then down all the sides. Make sure that the caulk is smooth as any imperfections in the caulk surface will be reflected in the edge of the concrete countertop. Caulk can be difficult to work with so be sure to practice several times on scrap material before applying it to your finished mold.

One of the key advantages in having concrete countertops is that they can be personalized to personal tastes. Adding these little details is impossible when dealing with Corian, granite, soapstone, or other countertop materials.

Cheng uses everything from old transmission valves and clutch parts from a car to semi-precious stone. Natural materials like coral, stone, tile, fossils, and petrified wood all add distinct character to a countertop when they are used as inlays and then polished along with the countertop surface.

One way to change the elevations on concrete countertops is to use MDF which is a type of fiber board. This is a way to stylize the concrete countertop and create visual interest that shows of the characteristics of concrete that make it so versatile-the depth and the ability to customize the surface.

Be sure not to overuse any design features or inlays. Fu-Tung designs by the rule, "When in doubt, leave it out." Just because so many materials can be used, doesn't mean that they should. Use restraint and create an elegant concrete countertop.

Foam forms allow for quick mold-making, they are easy to use, and can be used by just about anyone. Fu-Tung uses the foam along with double-stick tape to adhere the foam to the melamine base. You don't have to know how to work with wood or be a cabinetmaker-originally the molds were made out of wood.

All that is needed for this foam forming system is the foam, a mat knife, and double-stick tape. Once you have your template ready, take the double-stick tape and line the edges of your template. Then place the foam rails on top of the tape. You will also need form tape that will line the inside edge of the foam. This ensures that the edge of the countertop you are making comes out smooth and does not have ridges and impression left by the raw foam.

You may think the foam system is weak, it's not. When you pour the concrete into the mold the foam forms will not bend. As you place the foam into place around the template, be sure to create tight corners and joints. It is also important to get the formliner very flat against the foam. You don't want any curling or bubbling. Finally, begin caulking all the joints or seams that have been created in the mold with 100% Silicone caulk.

A great way to create a void in a concrete countertop form for a sink is to use a pre-formed foam sink knockout. Here Cheng uses an Elkay sink knockout. If the manufacturer does not provide sink knockouts contact them for their recommended sink opening size. This will help you avoid making the sink opening too small or large where sink drain boards or cutting boards need to be used.

If you have to make a custom foam sink knockout make sure you find blue packing foam that is the exact thickness of the countertop you are fabricating. This means if the countertop is two and one half inches thick, then the foam should be two and one half inches thick.

The outside of the foam is rough so it's important to wrap the foam sink knockouts with edging tape to give the opening a smooth finish. This is a plastic tape that has adhesive on one side. Make sure the thickness of the edging tape is the same thickness as the foam sink knockout. The smoothness of the plastic tape will make the knockout easy to remove after your countertop has been poured.

There is a reason Fu-Tung recommends undermounting stainless steel or porcelain sinks in kitchens. In the kitchen there is a lot of hard use and abuse to the sink that happens naturally-cast iron pots, scrubbing, using harsh soaps.

If you pour an integral concrete sink in this situation, then the sink will erode much more quickly than the stainless steel. Using an undermount sink is a design element as well. The edge of the concrete around the sink is now exposed and this shows off the natural thickness and mass of the concrete countertop. In addition, if the undermount sink is damaged it is easy to replace. Whereas with an integral sink it would be very difficult to replace any damaged areas.

Again, be sure to follow the sink manufacturer's recommended size when you are cutting a knockout for the sink opening. This ensures that any accessories that come with the sink (cutting boards, dish holders, etc.) will still fit inside the opening. If there are no accessories, or the homeowner doesn't want them, it is a good idea to make a small overhang with the countertop. This tucks the sink under the countertop which really enhances the depth and visual effect of the concrete countertop.

Here, Cheng has made his own pour table from metal and wood. There are several key characteristics to look for when buying or making a casting table. The table should durable, rigid, and flat. If you are an entry level concrete countertop maker, then you can use sawhorses and a double layer of ¾ inch plywood. If you are a professional, then you want a more versatile table.

What Cheng has done at his shop is create a 12-foot-long and 4-foot-wide casting surface. The frame for this table is made out of tube steel. There are levelers at the bottom so that each corner of table can be raised or lowered to create a completed level surface. If the surface of the table is out of level then the concrete countertop that is being made will also be out of level.

Another nice feature to think about when selecting a casting table is mobility. The casting table Cheng uses has wheels on all sides so that after the pour has been completed the countertop can be moved somewhere else to cure.

The surface of a pour table should be thick wood. Here, two sheets of ¾ inch plywood have been screwed together to make the surface. The wood surface allows the table to be screwed into. Melamine and the table vibrators will all need to be screwed into wood. It's important that a new, clean, sheet of melamine is used for each countertop that is made. Additionally, if the original wood surface gets too worn it can be replaced.

When you are thinking about building or buying a pour table, consider mobility, strength, and keeping the surface level. These are the important features needed for creating quality concrete countertops.

There are two types of concrete vibrators that can be used here-a pencil vibrator or a table vibrator. Both of these tools can either be bought or rented at a local rental yard. When using a pencil vibrator lay the tip into the material and be sure not to make contact with the bottom of the melamine below the concrete. This can dislocate some the inlays or materials placed at the bottom of the mold.

If you are looking for a more perfected finish on the countertop consider using a table vibrator. Here Fu-Tung installed two table vibrators to consolidate even a small concrete countertop, say for a vanity or bathroom. These vibrators will vibrate the entire table and mold. It is important to have a controller with these to control the oscillation.

Start out the vibration process at a high frequency to remove all of the air from the material. Then turn down the frequency and let it run for a little while making sure the concrete gets into all the corners of the mold. Vibrating at a low frequency also prevents too much of the large aggregate from separating from the mix.

Make sure not to over vibrate the mold. Over vibration results in aggregate at the very bottom of the mold and a soup-like material at the top. Remember we want the fine material at the bottom of the mold-this will be the finished surface of the concrete countertop.

There are a variety of pads used with this type of polisher that range from a 50-grit polishing pad (the coarsest pad) all the way up to a 1500-grit pad. The pads are attached to the polisher with a hook-and-loop system that allows for quick release when changing grits. The center of the polisher Cheng uses has a hole in it. This hole is the central water feed for the tool. The water keeps the countertop and polishing pad cool during this process.

After polishing the entire concrete countertop with a 50-grit pad, change the pad to a 100-grit pad and polish the entire surface of the countertop again. Repeat this process using the 200-grit pad, the 400-grit pad, the 800-grit pad and finally the 1600-grit pad. When polishing with the 1500-grit pad a sheen will begin to form. This is the almost shiny-looking finish you want. Remember, all this polishing is done before you apply a sealer or wax.

Notice, on each of the pads there is a tread pattern. This acts to spread the water out over the entire surface of the pad during the polishing process. The water feed simply connects to a standard hose.

From a safety standpoint make sure any wet-polisher that is used has a GFI (ground fault interrupter) shutoff. This feature should be built into the tool and will prevent electric shock. This works by automatically shutting off any power to the tool if there is a short in the system.

When polishing along an edge consider using a skirt. The skirt will simply attached to the polishing head and will prevent materials from spraying onto the ceiling. This is especially important for cast-in-place countertops where polishing is done in a customer's home.

When shopping for or renting a concrete polisher it is vital that it have several key features. One, it should be variable speed. The RPM (revolutions per minute) should be somewhere between 500 RPM and 3000 RPM. Be sure that a concrete grinder is not used. Concrete grinders are a completely different tool that should not be used for polishing countertops or with polishing pads. They will burn up the pads and can often cause harm to the countertop or the person grinding the countertop.

Second, look for a wet-polisher that has an on and off switch that will lock in the on position. It's helpful not to have to hold the on switch during the laborious polishing process.

There are several types of concrete polishing pads that can be used on concrete countertops-the hook and loop pads, and the quick release hard back pads. The hard back pads are more ridgid and provide a flatter finish on the countertop. In the polishing surface of these pads, the diamonds in the polishing surface are suspended in a part metal, part resin bonding agent. This allows for the diamonds to wear away faster, keeping the polishing surface of the pad much harder.

When selecting a grinder, look for the following features. Any quality grinder will come with a dust-collection bag and shroud. This will automatically collect and store any air-born dust particles created during the concrete grinding process. The dust that is collected can be emptied into the trash.

This grinder also has a built-in circuit breaker to prevent blowing a circuit in a home or workshop. Another nice feature is that the grinder has a shroud of bristles that prevent dust from shooting out the sides of the grinders and polluting the air. When grinding on countertops or floors, it's important to be able to grind up against corners. This grinder can reach within an 1/8-inch of a wall or vertical barrier.

Yet another thoughtful feature in this grinder is that the grinding head and cup wheel is spring loaded. This helps keep the grinder flat and makes it easier to create a flat concrete surface. Because grinders operate at around 8,700 RPM (revolutions per minute) it should be noted that this tool should only be used for aggressive concrete grinding. This is not a polisher. Polishing pads should not be used on a grinder. Only use diamond plated cup wheels on concrete grinders.

A grinder would be used on a concrete countertop, for example, when the surface has been poured and cured but there is a defect in the surface. Either the casting table was not flat or the troweling was done poorly and there is hump in the surface. The grinder can be used before the countertop is polished to flatten the surface. In addition, with poured in place countertops there may be times where air has been trapped in the countertop leaving a depression. Here, aggressive material needs to be removed so a grinder can be used.

When making concrete countertops, it is often necessary to polish the surface of the concrete like granite or marble to expose aggregate, inlays, or glass. During the concrete polishing process quite a bit of sediments and water are created as layers of concrete are removed from the surface of the concrete countertop. The sediments are suspended in the water you are using to lubricate the concrete polishing pads.

Rather than letting this polluted water run off into the environment, the responsible precaution to take is to set up a water filtration system. One of the key ways of doing this is combining the polishing table with the water filtration system. Make sure the table you build or buy is mobile as it is often moved around the fabrication shop.

The water recycling system Cheng uses in his fabrication shop is self-contained. This means the water is cleaned while it is in use. New water is not constantly being added. This is a great environmentally friendly solution to polluted water runoff into drains which eventually ends up in rivers and coastal waters.

The specific features that are useful in a polishing table are as follows: it must be rigid, mobile, it needs a rack for holding the countertop and it should have a splash guard. Used water from the concrete polishing drains into a reservoir. The water, that contains the sediments and affluence, is pumped into a centrifugal force filter chamber that separates the water from the material particles.

The system used by Cheng filters out particles down to 10 microns. Whatever water is leftover can be left outside where the remaining water is allowed to evaporate. This water recycling system is a responsible way to conserve water during concrete countertop fabrication and it also keeps public waterways and drains clean.

These hand-grinding diamond pads are great for polishing areas of a concrete counter that cannot be reached by the electric polisher. These pads, like the electric polishing pads, have variations in grit going from 120-grit up to 220-grit, 400-grit, 800-grit, and even 1500-grit.

Pads are also used smooth the rough edges of concrete countertops. Be sure that the polishing process done with the hand pads matches that done with the electric polisher. For example, if the polishing is done up to 1500-grit with the electric polisher, then make sure the hand polishing is done in sequence all the way up to 1500-grit.

Occasionally, concrete countertop surfaces will be etched by harsh chemicals in kitchens, by wine, or lemon juice that has been sitting on the countertop for several days. In this situation use a little water and these hand-polishing pads to polish out the imperfection. Start this process with a fine grit like the 800-grit pad and polish the spot up to the same polish as the rest of the countertop surface.

Sometimes the countertop surface is highly polished and resin pads that are typically used on electric polishers have to be used as hand grinding pads. This is because the hand grinding bocks may not have a fine enough grit.

Rubber rail and trivet strips are used during the mold-making process to create a relief in the finished countertop surface. After the concrete has hardened and cured, the rubber strips are pulled out of the countertop and filled with metal rails made from brass, copper, or stainless steel.

The rubber strips are 5/16-inch wide. The metal rails that are eventually placed inside are 1/4-inch wide. The metal rails are used for two reasons. One, these metal rails are aesthetically pleasing. The metal set next to the concrete makes it look warm. When used over seams in the concrete these metal rails visually stitch together the countertop uniting the two pieces.

Second, the metal rails are used to protect the concrete countertop from heavy abuse from pots and pans in kitchen. The metal rail or trivet strip is attached to the countertop using a two-part epoxy adhesive called PC-7. Be sure to mask off either side of the opening before applying the adhesive and inserting the metal strip.