This new sign for a suburban development was built to last, exposing only concrete fiberboard and powder-coated metal to the elements.

One construction material not often associated with sign making may prove to be a product for which there are many possible applications in the sign business. I previously have mentioned this substrate, but I think a couple of jobs we did recently would be good examples of how signmakers might use the concrete sheet product called Hardie Board, which these days is available at virtually any home improvement or building supply store.

Most often used for siding, soffets and trim, this normally textured material has no wood in it, is very paintable and, when supported correctly, is virtually impervious to the weather (water and UV). It is designed to last the lifetime of a new home or other structure, perhaps 100 years or more, which means this sheet material made of fiber reinforced concrete will certainly outlast any warranty a sign maker would need to stand behind.

The first project we will look at in this month’s Shop Talk is a replacement sign for a very nice suburban housing development. The original sign, set in a lot of decorative rock work at the gated entrance of this place, was a typical sandblasted wooden sign that had begun to deteriorate. The homeowner’s association contacted us about a replacement, and they asked for a sign with plate metal letters this time. We decided a good background for their new letters would be a sign faced and even trimmed with Hardie Board.

The letters, cut on a waterjet from 3/8" aluminum plate, and designed to look much like their old sign, were tapped for stud mounting and then powder coated black with a 60% gloss (satin finish).

The sign face was constructed by laminating 8" wide woodgrain textured panels to a primed sheet of ½” MDO. A healthy amount of construction adhesive was used to bond the sheets together. As mentioned, even the trim, a small raised 1" wide border around the edge of the sign, was made from this concrete material. It was designed in our graphics program, broken into several easily manageable sections, then cut on a waterjet as well, and so was the curved top section of the sign face.

Fortunately, we have easy access to a waterjet at our sister company W.P.C. Services, but in most cities of some size, there will be a company offering this service. The nice thing about working with concrete board this way is the cutting is dust free, and it cuts like butter on this type of cutting equipment.

For anyone who may want to have something cut from Hardie Board this way, simply tell your waterjet contractor it has a machinability similar to Wyoming limestone rock, which is very fast to cut. If a cad drawing is provided (.dxf file is common for CNC cutting), it will not take them long to cut the items you need.

Though the sections of the face had been well glued together, the screws and glue used to hold the trim in place around the edges of the sign are further insurance against any delamination. As shown in the photos, we did not do the finish cutting of the MDO backing until the face was finished, simply using a hand jig saw and following the contour of the Hardie Board face and trim.

The letters were cut first from mill finish 3/8” aluminum plate on a waterjet, then drilled, tapped and powder coated a durable satin black finish.	What would become the raised edge trim of this sign was also cut by water, in easy sections, which would later be glued and screwed along the edge of the sign face.
Hardie Board planks, 8” wide, were used to construct the facia of the sign, and a bit of work with a rasp was done to be sure they still looked like planks once they were assembled.	The sign face sections were bonded to a primed piece of MDO using a good deal of construction adhesive.
The trim pieces were then glued in place and allowed to dry.	After several hours of cure time, the extra MDO was trimmed off with a hand saber saw.
The only screws in the sign were countersunk and placed around the border to further secure it against any delamination.	The concrete board panels are designed to be paintable, and a good quality acrylic latex paint, applied with a brush, will work as well as anything we might put on it.

On the job site, we first had to take down the old sign, and fight the wasps who resided behind it, then determine what type of mounting we would need. There was a piece of steel angle placed behind the sign by the original masons, but we determined to ignore that and bolt in some treated lumber stringers using lead anchors and lag screws. The sign was easily secured to these mounts, and then we set about gluing the stud mounted letters and logo in place.

With only powder coated plate metal letters and concrete board face and trim exposed to the weather, I really expect this sign to last beyond the end of my career, and these homeowners will surely get their money’s worth on the replacement sign they purchased.

A second job we’ll look at involving the same type of concrete panels is one we did for our own shop recently. When we bought our current building about 18 months ago, there was a pair of gates, of cheap aluminum tubing construction, which were used to close the drive into the property after hours. Wind storms and a falling tree has taken a toll on these gates and we designed and built another much nicer set of powder coated steel gates to replace them with.

A pattern drawn on a plotter is here being perforated to match the stud patterns on the backs of each letter or element in the design.	Sloan takes down an old deteriorating sandblasted sign to make room for our newer version, which should last a lot longer than the original.
New mounts of treated lumber were bolted in place to provide something to attach the new sign.	Lastly, the powder-coated letters are stud mounted in place using silicone adhesive in pre-drilled holes.

The main sections of the new gates were to be covered with decorative cedar planks, and over this surface we wanted to mount some type of dimensional letters with both our business names, Rick’s Sign Co. and Oilfield Signs of Texas. Since we want the gate lettering to be readable either open or closed, we needed to make two complete sets of these 28 letters, or 56 raised letters to complete the job.

The experiment was how well Hardie Board concrete panels would fare as material for making raised textured letters for outdoor signs. Cutting this type of material with a router or saw would not be a good idea because of the dust involved, which is hazardous to breath even when sweeping up because of the silica in its formulation. But cut on a waterjet, there is no problem with dust and no clean up.

To make the job go faster, I first painted the 8" wide textured concrete boards with exterior acrylic latex black paint on both sides, and also planned to cut both sets at the same time by stacking two boards together and cutting them simultaneously.

As it turned out, the machine could have cut the entire job in 15 minutes or less, but because I chose a Souvenir font, with many curves, rounded serifs and few straight lines, the computer calculations for all those curves slowed the machine down a bit. But it still cut all letters in less than 25 minutes.

Now, the material cost per letter was around one dollar each, and the cutting time on even a CNC waterjet machine was less than $2 per letter retail. Even with a little cost added for setting the job up, and tweaking the CAD file, this would make each letter cost under $4 not counting the time to paint them.

Another simple project we did recently using Hardie Board, this time for letters, was several sign panels for some new gates we constructed for our shop. The planks this time were sealed with a primer coat of paint before cutting.	Two boards were stacked and cut simultaneously to make a matching pair of all lettering, since we were making sign panels to go on both sides of the gates, so they could be read when the gate was open or closed.
In all, nearly 60 letters were cut from concrete fiber board in about 20 minutes cutting time on the waterjet.	A final coat of acrylic latex paint was applied by brush to fronts and edges of all letters.
The cedar board panels were assembled earlier, and here the letters are being screwed into place using ¾” wood screws. Pilot holes must be drilled through the Hardie Board letters and some care taken to not bend them over a warped board as this rigid material does not bend and can crack if abused.	This photo shows one side of one gate, and there are two gates and each are double-sided, totaling a lot of letters. But these “concrete” letters on cedar panels should last our shop for many years.

This type of letter might have plenty of application for ranch signs, development signs, church signs and so forth; that is anywhere a low cost dimensional letter would be ideal. A local waterjet cutting contractor would have no trouble cutting this material for any signmaker, and cutting it fast.

Lastly, the edges of the letters were painted with the same black exterior latex trim paint, and one more light coat was painted on the front surface only. The letters were simply screwed to the cedar boards used to construct the sign panels that would be mounted on both sides of our new gates.

This project, using cedar faces and concrete panel raised lettering, should last for a long, long time. And, since we were working for our own shop, keeping the cost in check was worthwhile, too. Certainly, some of our clients have similar concerns, especially in this economic environment. But, at least we know one more way of making extremely durable dimensional letters, and even sign faces, which we can produce locally and market to our customers for a variety of commercial sign projects.