Jamie, check the Hypertufa forum and do a search there for blocks or retaining wall... you'll find lots interesting & useful information there.

~GC

try sand casting. Easy to do. Take a box line it with plastic put in wet sand. Make your indentation the size you want for your brick and pour in your mixture, level it off and wait 24 hours. if you want uniform molds check eBay for some inexpensive reusable molds. If you want to email me privately I do concrete stones, etc. so I can give you some venders to check out.
Paws

I was cruising thru ebay earlier looking for face molds and noticed molds for retaining wall bricks. Look under concrete molds. The folks in the hypertufa forum do some unbelievable things so be sure and check it out.

Jamie
It's very easy to make even complicated interlocking brick molds using sheets of blue styrofoam.
These can be cut shaped glued to make a mold for even a complex interlocking brick.
If it requires a multiple piece mold get a few yards of surgical tubing to tie it together. Holds very tight. Much better than tape of any kind because it applies tension to keep the mold tightly together.
The real beauty of styrofoam is concrete doesn't stick to it so you can use it over and over again.

Oh contraire, mon frair--concrete most assuredly does stick to styrofoam. You will either need to use a mold release (motor oil, vegetable oil) or loosen your styrofoam mold from the concrete while its still at a gelatinous stage.

Jamie, my advice to you (as someone who has actually made these, unlike Tufaenough) is make your molds as simple and as sturdy as possible. You're going to be using them over and over and wanting to unmold quickly so that you can fill them again. I used 2 X 4's put together with long woodscrews and they even started coming loose after 100 or so uses. Next time I'll use 2 X 6's for bigger blocks.

Deb

I use blue styrofoam molds everyday.
Concrete does not require a release agent.
Although it is easier to keep your molds clean if you do.
You can't make an interlocking block with a 2x4 mold as anyone who has made them would know.

Deb is make simple bricks. Perfectly useless for a retaining wall.

You can also imprint a brick pattern into blue styrofoam to give you a brick that actually looks like something other than a block of mud.
If you email me I will tell you how this is done with any brick or rock.
It's my own technique and extremely easy to do.
No skills required.

Jamie,
You can take any brick and soak it with acetone. When it's still wet, but not dripping, place the brick on your foam and it will melt away the foam.
Loren

David, I think you're talking about styrene boards. I've been using the styrofoam boards with the little beads that are very good at embedding themselves in cement mixtures. I cut little wedges from styrofoam to insert in the block forms to make blocks that will go around a curve.

You're being preposterous but I refuse to be insulted. I never said my blocks were anything but simple blocks. They have a poured footing and are mortared together with gravel behind them. I didn't say they were strong; matter of fact, I didn't make any claims except that I had made a lot of them.

Like I said, I'm sorry for hurting your feelings. My concern was genuine, even if you feel it was misplaced. Peace?

Deb

i saw this post:

Imprinted patterns in your bricks. RE: How do you make concrete

can you tell me how you did this, thanks