[sloweather]

A few months ago I tried my hand at making faux stone troughs for planters. I started with basic hypertufa recipes, and decided that they were too light and weak, and didn't look enough stone-like for me.

Hypertufa uses ground peat, vermiculite, and horticultural perlite for lightness, along with sand and Portland cement. Sometimes they add a chopped fiber called fibermesh for strength.

So I eliminated the ground peat and fibermesh, and went with more mortar like formulas with more sand and cement.

I kept the vermiculite in some recipes. It adds a nice sparkle. I also kept the perlite in some. I also tried white Portland cement, as well as diatomaceous earth (DE), and dry concrete colors.

I don't have a photo handy of the first trough I made and gave away.

These first ones I hand molded in wooden forms using a trash bag as a release agent

Here are the brown and green ones.

I ordered chromium dioxide for the green color. We have a lot of gree serpentine outcrops around here.

After they cured for a day, I unmolded them and distressed the surfaces with wire brushes and stone carving chisels.

Then I used the white cement, silver sand and DE with a little vermiculite for sparkle to try for a white marble look.

Initially, I didn't like it, and for some reason it hardened up way too fast. So I tossed it aside for a while.

Every now and then I'd look at it, and it finally hit me. I got a gallon of muriatic acid from the garage, poured an inch in a plastic tub, and etch-eroded all of the surfaces. I like it better now.

After that, I applied everything I learned to a pump water feature. This was made with an outer wooden mold and 2 slightly tapered inner plug molds for the cavities. The cavities are connected at the bottom through the cast-in partition by 3 holes made with wine corks.

I variegated the mix by portioning it out and then adding different colors as I packed it into the mold.

After it came out of the mold, I distressed it the same as the others, minus the acid treatment.

I like it a lot...

Hint... How to get an antique pitcher pump. But a cheap Chinese one from someplace like Northern, and leave it out in the weather for 10 years.

 

[Mark / Ohio]

Those turned out really well Chris! :thThumbsU

The one time I tried to cast cement to make a couple replacement top collars for my chimney it looked great until I took it out of the mold and it crumbled to pieces. I broke down and drove up to the Amish area and bought a couple and never tried it again after that. Must of had the mix too dry or maybe the wrong type of cement. :dunno:

BTW, I noticed you were due a 5 year banner under your name and attached one. Where does the time go?

 

[sloweather]

Hi Mark,

Re: Time

Well, you know, time flies like an arrow, fruit flies like a banana...

Thanks for the banner!

Chris

 

[sloweather]

So, onward to the raised bed question... Bear with me and you'll see the connection.

We have raised beds out back, partly due to the poor red rock "soil" that our house is built on, so we can have decent dirt for growing, and partly to screen the bottoms to keep out the gophers.

We made them 6 or so years ago out of "landscape timbers" from Home Depot. They were inexpensive at less than $2 each for an 8 footer on sale. However, they are starting to decay.

I looked at replacing them with other things, especially self stacking concrete block systems. They all seem to run $3.50 to $5.00 or more per face square foot. A little too rich for us right now for the size beds we need to replace.

The other day I was out in the Think Tank, AKA spa, having a glass of wine, and I got to thinking. (duh) What about making soil cement out of the abundant red rock? Actually, it would be more like soil concrete, rather than the classic soil cement. Just Portland cement and the red rock.

So, I did a little semi-scientific testing. First, the classic jar test. Soil and water in a Mason, shake and let settle for a day.

Because of the soil and the grading that was done for our house, there isn't really any topsoil or organic matter. All I did was take out any weed root balls.

Hey, not too bad! About 16% fines, and then gravel and stones.

Then I decided to do a little screening. I shoveled a sample into the wheelbarrow, and then screened it through 1/2" and 1/4" hardware cloth. and window screen.

Again, not too bad! About 30% sand and clays < window screen size, 35% window screen to 1/4", 15% "pea gravel" 1/4" to 1/2", and 20% > 1/2".

So, the next test was to make a block. I made a damp mix if 1 part Portland cement and 6 parts red rock. (A classic concrete is 1:5, but I don't need a lot of compressive strength for raised be walls).

The mix was packable, not pourable. I tamped it into the mold pretty well. This picture is after one day to cure a little, unmolding, and then distressing with a wire brush right away. The right side is distressed, the left as it came out of the mold.

That looks pretty good! I'll let it cure for another week or 2 and then see how strong it is. And to think that for all my work looking for a "natural" looking mix for the faux stone troughs, the answer was literally under my feet.

Not including form lumber or rebar, I can make raised bed walls for well under a dollar a square foot.

 

[glenn27]

Chris--that's really something--never thought of stuff like that....

Very inventive and creative--My hat is off to you!

glenn

 

[Mark / Ohio]

On site block factory! :fing32:

We have a lot of clay soil here outside of the river and stream valleys. I know of some old brick farm houses around here the bricks for the houses were molded and fired right on the property for the house. They are not the prettiest looking bricks and on the soft side but yet the houses are still around 100 years later.

 

[DJ in WV]

I'm sorry I missed this. Those are really cool! I love the fact that you're using material found on site. Not many of us have that opportunity. I have lots of clay but I've never explored or even thought about pursuing anything.

 

[Mick Oz]

How did the raised beds turn out?