Building rock fenceposts - concrete vs mortar?

[gwandsh]

Hi all

My newest project idea is to build a "fence" composed of small rock posts with single rails laying between them. It's an ornamental fence, not really designed to do anything except define the extent of grass I need to cut. It would only be about 24" off the ground.

I had envisioned using old milk crates, lining them with plastic, setting rocks inside and adding a mix of concrete or mortar as an adhesive to bind them together. I would carefully invert the crate once the mixture is set up, and voila, I have a fencepost. What I really hope is that the rocks will extend out past the binding mixture, giving it a kind of masonry wall look.

While I have done lots of simple concrete work, I haven't worked with mortar. I suspect that when the mixture is added to the rocks, it will ooze out between them and eventually fill the gaps so the whole thing turns into a block or cube.

Anybody tried this type of construction before and have any pointers or links to give me some help. The whole point is to make it simple and quick to fashion, using materials at hand (rocks and milk crates I got...).

Cheers

[Colbyt]

The concept sounds nice. The method I suspect is not going to work. Whether you use mortar on concrete it will ooze out and surround your rocks within the container.

Sand casting is the method to create irregular shapes. Once the form is removed the sand is just rinsed away. You might be able to run with that concept but I am seeing it as being almost as labor intensive as hand building each post where it will set. A completely untested, unresearched concept would be to use plastic bags to fill the voids in lieu of the sand. You are going to need a dry mix whether it be mortar or concrete.

Do keep in mind that a dry mix using concrete will leave a lot of the aggregate showing when it sets. Of course the rock in the ready mix bag is just river gravel not big stone chunks.

Be sure to post back and let us know how you did it. Pictures linked to from elsewhere are always nice.

[JIMMIE]

Make a concrete post and face it with fake or real rock.. Wife's cousin has something similar but on a larger scale. Concrete culvert faced with rock. Looks like stacked stone. Gas coach light on top.

Jimmie

[Joe]

Before you get too committed, check out the offerings at your local concrete cast products store...the guys that supply the contractors with all the bricks, blocks, parking chocks and such. They may have something nice to fit your budget and then you could get the project underway and even finished before next Labor Day.

Joe

[Harry K]

Use concrete, mortar only makes a weak "glue". Mortar construction relies more on the weight of the material being stacked than the bonding of the mortar.

Harry K

[HeyBub]

A local university building had pillars of concrete that had been pneumatic-hammered to expose the aggregate. It was billed as "man-made stone" until some wag pointed out that "Only God can make a stone."