Chronicles of the Design & Construction of Two Waterfront Hurricane Proof Dry Stack Modular Green Custom Homes
1. Villa Lagoon, Wilder Italian Style Home
2. Nasello Italian Style Home

Concrete Acid Stain on Exterior Blocks for Frieze

March 3, 2008

Previous notes here on preparations for concrete acid stain exterior frieze to go just under the cornice on Villa Lagoon.

I need pretty sunny, warm days to be outside doing this block coloring. Luckily we had a nice weekend, really breezy, but sunny and warm. I finished drawing my basic shapes on Saturday, March 2nd, and Dave Perry and I began applying color. I was making home-made stamps from that thick foam that craft stores sell for kids activities and mounting them on pieces of flip-flop soles to give them enough thickness to hold on to them and dip just the surface of the stamp in a shallow dish with the acid stain color solution in it. The foam is easy to cut with nice edges, and the flip-flop backing doesn't have to be cut with tons of precision. But, Dave had a better idea. He suggested I try using pieces of the knit fabric-foam-core drink insulator stuff, that cozies, or huggers are made from that fit around a canned drink. We got out a bunch of them and found that some were thicker than others and some had lumpy printing on them. Using the thickest and flattest printed ones, I cut out shapes of leaves, flowers, etc to make into stamps.

This turned out to be a great idea. The foam hugger material held just the right amount of liquid concrete stain and didn't allow it to run out and make a mess.

I used Gorilla Glue to attach the cut out huggie foam to the backing piece cut from flip-flop sole. It didn't dissolve the foam or the shoe foam like some solvent based glues do and it doesn't dissolve in water or liquids I was using like white glue will do. But, Gorilla Glue expands and makes a type of foam as it cures , so to keep everything nice and flat (not lumpy from expanding foam), I placed the freshly glued stamp on a glass table and put a book on top overnight. Perfect-o, any extra foam just squished out the sides.

Coloring the concrete...

Knowing that I had a lot of line to mark out with green, I wanted to use something that would go faster than using a brush.

I started doing the vine scroll lines using a cleaned out former paint bottle that has a very small nozzle. At first the concrete acid stain came out of the bottle too fast and was too hard to control. Then Dave had the idea to put a piece of cellulose sponge crammed into the inside of the tip. This allowed me to squeeze the bottle when necessary and fluid still flowed, but it slowed down all uncontrolled dripping. It was very difficult to get a smooth line when gliding the tip along the pencil line due to the multitude of small pits in the block surface. But I decided that the over all effect would be OK, just a bit more rustic. I went up on top of the house to look since that pretty well simulated the distance the design would be viewed from.

But the biggest problem was that the green acid stain refused to turn green color. Or I should say, my concrete blocks refused to turn green when I used the stain that was suppose to produce a green color. And, the different blocks really reacted differently to the stain. Some of my blocks were hollow, regular blocks and several were solid cast lintels that will go over windows. These solid pieces were poured at a totally different time and obviously of a very different cement mix.

And the so-called "Green" didn't even show up well at all. I decided to give it some time, work on other colors and see what it looked like the next day.

On Sunday, while I was working on the center designs, Dave used one of our home made stamps to go along the edges of all the blocks and add the blue circles.

You can see here how different the blocks look with the exact same treatment. The colors you see here are not what the end result will be tho. We did a minimum of two coats, sometimes more.

Next day, I realized that the green color just was not going to develop into any kind of color at all. I went ahead and used my other colors, Tan, Wheat, Umber & Red, to paint the inside elements. Then I used the Black to go back over all the pencil lines that had the green on them. I also made the change to switch to a small brush. It was tons easier than using the squirt bottle. I only kept a small amount of acid stain in my container at a time so if I had an 'accident' the damage would be minimized. And I did actually go flying twice. I hit my shin really hard on one of the wire handles sticking out of the block top one time and tore the skin up. I walked around with an ice bag under an ace bandage for the rest of the afternoon after that tumble. Fortunately, both times that I fell, when my stain cup went flying, the color flew out on the rocks not the blocks ! I was SO GLAD.

In Progress


The back rows are for the east side of the house. I started on the west side first since I would not see it up close, nor would anyone else,  very often. I will do them next. Mean while, the front row is finished and ready for Mike and Ryan to stack them on the walls. The distance here, from the top floor is abut the same as the viewing distance will be from the ground once the blocks are in place.

So I went over all the vine lines with the black acid stain , on top of where I had done it in green before. I knew that the black might not be as dark since the surface had already reacted with the previous stain attempt. Then I mixed half and half black and my old Superstone green and filled in the leaf areas and made some new leaf curls. It actually kinda looked green.

Just for fun, I put in a couple of fish. There are a few blue birds too. The shape is of a mocking bird, but it is blue. I consider it a bluebird with attitude.

I tried to keep certain elements in the over all design in a repeating rhythm, and then alternate and vary the other parts. Not using a particular system, I just inserted the bird and the alternate whelk shell in the center of the swirls every so often. Plus, I was kinda free-form on the various leaf and curl patterns. One of the last things I did was go back and add small blue bell shaped flowers and that extra touch of blue in the design made a lot of difference.

Before I left for the day, I sprinkled some baking soda on the face of the blocks to help neutralize any residual acid stain and maybe help it to not make runs and drips in the rain that was on its way.

Over all I am very pleased with the look of the concrete acid stained frieze and think it will be really appropriate for the house.

This row of blocks will be stacked pretty soon. We are waiting for some capitols for our columns from DAC-ART and cannot continue with the porch until we get them.

Note: later I didn't bother with the baking soda and still had no bleeding of color that I noticed.

See how these concrete stain designs look on the house once the blocks are stacked in the next post, March 13, 2008.