(Article and photography courtesy of Concrete Decor Magazine)

By Elise Crain

The only limit to decorative concrete is your imagination. You may have heard that for years and it is just as true today. Products, tools, professional training and ideas are just waiting for you to make the most of your opportunities.

Picture an eagle with an eight foot four inch wingspan! Darrel Adamson, Engrave-A-Crete, created this image at a recent seminar. A line drawing of the eagle was scanned into and enlarged with a CAD/CAM program. After tweaking to make it just right, it was put on a floppy disc and inserted into a computer-controlled mill to cut a template. Seminar students used carpenter's pencils to trace the outline. Reactive stains of various colors were applied with pointed brushes to simulate feathers. DecoSup concrete dyes were used for the flowing ribbon. After curing, the surface was washed and a clear sealer applied. The template was returned to the concrete and, using a Shark engraving tool, the cutting began. Engraving provides a clean, crisp outline resulting in beautiful concrete images like those shown above, Bald Eagle or colorful butterfly.

Company logos, family crests, pictures of pets or children can all be engraved. The caution is that it may look "cool" in the beginning and then not so cool when the household or business has to move.

Freehand creations are good for stones and natural looking surfaces. Marvin Dodson, Rare Earth Labs produces concentrated stains that provide a wide variety of colors and tones. His designs are both engraved and freehand. He suggests when not using equipment (such as Engrave-A-Crete or Kaleido-Crete) the design be placed using graph paper and drawn on the concrete with chalk, soapstone, pencil or marking pen. Designs can also be placed with a black permanent marker since stains will not bleed across the marker lines, according to Dodson. The freehand stone pattern is an excellent choice to incorporate existing cracks as part of the pattern. Cracks can be cleaned out, or made bigger, and form the skeleton for the new "look."

When planning a concrete creation, the first thing to look at is the concrete surface. Is it structurally sound? Will a topping (overlay) be installed? Since the survival of an overlay is the bond, concrete must be clean and the overlay properly applied if these types of creations are expected to last. Adamson points out that the hardness of an overlay and concrete are not the same, therefore the harder the surface, the cleaner the cut.

A broom finish on an existing surface makes a more authentic looking brick pattern. To achieve a polished marble look, smoothness is better. The surface can be changed before your creation by grinding, sandblasting, polishing, shot blasting or with an overlay.

Tools typically used include DeWALT, Milwaukee, Black and Decker or Mikata hand-held right-angled grinders and saws, Dremel type engraving pins, the Kaleido-Crete systems, or the Harris Accu-Glide concrete saw. The Engrave-A-Crete System uses specialized electric-powered saws with diamond blades, the Kaleido-Crete System uses pneumatically powered tools containing fine steel rod impactors, while the Harris Accu-Guide allows cuts with straightness of +1⁄32" over thirty feet. An operator can achieve up to 5,000 linear feet of production a day with the Accu-Glide. Star Diamond Tools also has a special convex blade used in an angle grinder to cut circles.

Crafters develop their own favorite tools and techniques. Every experienced creator of concrete images emphasizes the importance of quality tools and diamond blades. Inexpensive blades become expensive in the long run because they result in chipping and rough edges. These blemishes impair the overall quality of the job. Not getting paid because of poor quality is one thing, what you leave behind can be an even worse experience. Adamson says that achieving straight lines is as simple as purchasing the proper equipment and diamonds that are specifically designed for decorative grooving. John Bernat, Star Diamond Tools, reminds us "high quality diamond blades run smoother and cooler and always produce fine clean cuts."

Patience is right behind imagination in required skills. Once a cut is made, it cannot be undone. Grinding or making other cuts to provide balance can change it. It can be widened or angled differently. Stain may be used to disguise or create a diversion of the eye.

Is this art? Yes! And that is the basis to determine fees you will charge for your work. The tools available today allow someone with limited skills to become an artisan. The person using the correct tools must understand concrete and must try not to be affected by those who are watching. Advice from sidewalk superintendents, including owners, must be taken lightly. If you wear earplugs for safety, they may also provide a barrier to unsolicited advice. Dodson says, "as with anything else ‘practice makes perfect.'"

Multi-media artist, Elizabeth Anderson, Anderson Enterprises, discovered concrete as a new medium. Working on a project for Bass Pro Shops in Islamorada, she used INCRETE stains with metal shavings and engraved fossils on the floor, including that of a seven-foot tarpon and the nautilus shown here.

Creativity, skill and product knowledge are the reasons you can be well compensated. You are using special skills to add value to your client's property. If you are shy about asking to be justly compensated, your customers can interpret that as lack of confidence on your part. It is also important that your trucks, your equipment and your workers look professional. You want business owners and homeowners to be proud that your trucks are parked on their properties. One last hint from Adamson: install ID medallions on all your projects.

Selecting the right diamond blade to run on concrete saws is the best way to maximize your equipment investment. More and mare companies offer diamond blades. But how can a contractor choose the right blade for the right saw?

How diamond saws cut

Blade performance is a combination of the material being cut, cutting speed and blade life. Changing one variable affects the others. Aggregate hardness and size, amount of steel reinforcing (rebar) and whether the concrete is green or cured affects blade selection. The diamond blade segments are made up of a mixture of diamonds and metal powders. The composition of the bond that holds the diamonds must be matched to the hardness or softness of the material being cut. The simple rule of thumb to remember when selecting a blade: Use something hard to cut something soft and something soft to cut something hard.

Selecting the right diamond blade to run on concrete saws is the best way to maximize your equipment investment. More and mare companies offer diamond blades. But how can a contractor choose the right blade for the right saw?

Know your saw

You must know the blade specifications required by your saw. Do not use blades not recommended by your saw manufacturer on your saw. You can control cutting by adjusting spindle speed. Increasing spindle speed makes the diamond blade cut harder, decreasing the spindle speed makes the blade cut faster. Harder, less abrasive materials require slower spindle speeds and softer, more abrasive materials need faster spindle speeds. Never operate blades at rotational speeds greater than the maximum RPM listed on the blade. Over speeding can damage the blade or cause serious injury.

Know the differences between blades

There axe several types of diamond blades from which to choose. High-speed segmented blades are the most competitively priced on the market and make fast, smooth cutting in many materials. They provide a constant depth of cut and fewer blade changes. Most come with a 1" arbor with a drive pinhole or a 20 mm arbor. Dry walk-behind concrete saw blades are ideal for intermittent cuts in concrete, green concrete and asphalt. They cut without water and are often used in patch/repair work or expansion joints. Dry and wet masonry blades provide a consistent depth of cut with less dust than abrasives. Segmented dry small-diameter blades are used on hand-held circular saws and most right angle grinders.

Use them on concrete block, marble, soft granite, stone, tile and other materials. Dry tuck-pointing blades are used on hand-held circular saws and small, right angle grinders. Dry tuck-pointing pins can be used on routers and clean out mortar from mortar joints and butt (vertical) joints. Dry tile blades are continuous-rim blades used for chip-free cutting on tile saws, right-angle grinders and circular saws. Dry segmented cup grinders, used on right-angle grinders, they grind all types of concrete, masonry, brick, block and stone.

Segmented or continuous-rim blade?

Segmented and continuous rim blades are designed for the same task, but offer differences in speed, performance and longevity. Segmented blades have a thicker segment and higher diamond concentration for longer life and greater ability to resist very abrasive materials. They also have a thicker core and open gullets, so they are well suited for high production and heavy use. The blade segments are laser-welded, so they can be repaired.

However, segmented blades have disadvantages. The thicker segment results in a slightly lower cutting speed and the open gullets make a rougher cut. Continuous-rim blade have a thinner rim and greater surface area that delivers aggressive cutting speeds and less dust and a smooth, chip-free cut. It's a good choice for very hard materials such as stone, marble and decorative edges. Like segmented blades, continuous-rim blades also have downsides. The thinner rim and lower diamond concentration result in shorter blade life and wear fast in very abrasive materials. Their thinner core and no gullets means they cannot dissipate heat as fast as a segmented blade and can warp when overheated. Finally, they cannot be repaired.

Your diamond blade distributor is provided with a wealth of information from the manufacturer and can help with additional blade selection tips.

The size of the aggregate affects blade performance. Large aggregate makes the blade cut slower, while smaller aggregate makes the blade cut faster. Heavy reinforcing with rebar also tends to slow the blade and make it wear faster. The time the concrete has had to cure greatly affects how the material will interact with the blade. Freshly poured or green concrete is softer and more abrasive than cured concrete. The blade will need a harder bond with undercut protection to cut green concrete and a softer bond for cured concrete. Undercutting is a condition in which the steel core of the blade wears faster than the diamond segments. It is caused by highly abrasive material grinding against the core. The best remedy is to choose a blade with under-cut protectors on the core or pol-yarc segments.

Your diamond blade distributor is provided with a wealth of information from the manufacturer and can help with additional blade selection tips.