You will want to start out by picking your colors. Some folks think that this can be one of the most complicated parts of stamping concrete. But as long as you are not to picky I’ll show you how pick out your colors. You may choose to start off with color swatches, the best way I have found to pick your color from a color swatch is to pick a color from the swatch and then go back one or two colors to get the actual color that you want. This is very similar to picking out a color that you want to paint a room. There are many variables such as indoor lighting and the other colors in the room (sofa’s, rugs drapes etc.) that you wish to paint. I am sure that you have picked out a color at the paint store and started to paint your room and suddenly you noticed it just doesn’t seem to match the color you picked from the color swatch, from the paint store. This is what I call perceived vision.
If you can understand what I have just mentioned this also applies to picking out a color for your stamped concrete job, there are many variables of perceived vision, such as sunlight and surrounding colors, such as the color of your house, landscaping and grass. One other way to pick your colors is to visit your decorative concrete supplier and check out some of the samples or photos they may have hanging on there wall. You may ask them or any one else if they know of somewhere there is a stamped concrete project is at so you can see the actual finished project and see for yourself how it either blends or contrast with the surrounding landscape.
Let’s start pouring and finishing your stamped concrete project, I suggest that you start with no more than 100 square feet. First, let the concrete truck driver put the color into the concrete truck for you, and let it mix for at least 10 minutes. Often you may notice some streaking of the color as it comes out of the concrete truck, not to worry. You will want some color differences as this will resemble the natural colors of what ever impressions or stamp that you have chosen for your project. For example if you look at a rock you will notice that it has many shades of the same color and often some other colors. Your next step will be to insert the concrete into your forms, you will need what is called a screed board or a 2″x 4″, the purpose of a screed board is to level out the concrete inside of your forms and to also knock down the aggregate or rocks inside the cement. Drop the wet concrete inside your form work and leave it about a ½” higher than the top of your forms. A good way to get a rough grade is to use a tool called a concrete rake or a square edged shovel will do. After you have gotten the concrete ½” above your form work you can start the “screed” process. You will definitely need someone to help you with this process. After you have found someone to help you, here is what needs to be done. Each person will get on one side of the screed board, as each of you will start to pull the concrete towards the end of the form work leveling as you go along. At this point you will need a bull float to close the surface of the concrete. Generally you will run the bull float from top to bottom across the concrete overlapping each previous pass approximately 50% and then repeat the process from side to side. Do not worry about getting it completely flat, as once you begin to stamp it will not be flat at all. Do not get hung up on small dips or small elevation changes in the concrete. Now you may begin to edge the perimeter of the concrete with an edging tool, again do not get hung up on doing this perfect, especially if this is your first time. Now you will run a fresno across your project in the same manner as the bull float.
Ok you are ready to stamp your project. Before the concrete truck gets there, you will want to pour the liquid release into a garden sprayer and also get yourself some surface retardant and do the same. Liquid release simply allows you to place the rubber stamp onto the concrete without removing the finish of your concrete, the surface retardant will slow the setting time of the concrete if you feel you are getting a little behind. Simply spray the area you will be placing your stamp with liquid release and the stamp itself before you place the stamp onto the concrete. You will not want to spay the entire project at once as this will speed up the setting time of the concrete and it will more than likely dry up before you get to the end of your project. Lay each stamp down and set the next stamp tight against the stamping mat that is already on the concrete, making sure that the handles on the stamps face the same direction. If you have help it is best to designate a specific role for each person. What I mean by that is, one person will spray the liquid release, one person shall pick up and place the stamp mats and the other person will actually step on the mat and make sure it has left a good impression. Repeat this process until you reach the end. One other thing you might do while your stamping is to use a roller tool to flatten out the bead that will form when you place the mats together. You may also want to do this process with a hand grinder after the concrete sets.
Let your project cure (set) for about 3-5 days and it is time to add secondary colors or the antique stage. For this you will need to pick out an antique agent, I suggest you use charcoal or grey for your first time. You will also need to get some xylene, one gallon for every 80_90 square feet. You will then add 5 tbsp. of antique agent to the xylene in a 1 gallon garden sprayer and stir or shake for about 45 seconds. In a circular motion spray the secondary colors, or antique, onto the stamped concrete project, ( spray only a small area at first, let it dry and you should see a light dusting on top of your project) keeping in mind to spray some areas thicker that others, while being careful not to spray it on to thick, this will give you a more natural looking finish.
Let the xylene dry and apply two coats of; non-yellowing, solvent based acrylic sealant. Your project will be a lot darker when you apply the sealant than you anticipated, not to worry, the sealant also needs to cure. Within a day or two it will lighted up to your perceived vision.
If you have further questions about this process you may visit my web site for further details. I am at www.howtocrete.com How to Crete