Yes I cast the bricks face down. I make a mold from 1.5 styrofoam. You can make the brick very deep this way for retaining walls.
I tie the styrofoam together with surgical tubing.
A few wraps and you have a brick mold stronger than if you glued it together. Remove the tubing later and the styrofoam just falls away leaving you a nice brick.
Right now I'm doing some bricks with a 5x10 face 12 inch long.
I only do a thin face on the brick with my good recipe about 1 inch or less then fill the brick molds with cheap redimix later. I have dozens of brick facings waiting to be attached to their backing.

Getting to wax.
Wax can be build up wax on your bench top in layers and carve it. Then when hard you can break it and move the pieces. This will give you a brick face that looks like fractured sandstone. You can use various colors of recipe and creat any look you like. Thin white bands like quartz, red bands, black, etc.
I do a dark blue brick face with white stucco chips as exposed agregate that people just love. I do it in black as well.

You can use anything on the bench top to pattern your brick face. Pea gravel covered with handy wrap makes a cool pattern. A chunk of bark is cool. you could use leaves galore.
Sunflowerseeds can be used. The birds will come along and remove the seeds leaving a cool pattern.
You can do great patterns with crumpled tin foil.
There is no end. If you want smooth river stones put down a layer of damp sand, add the riverstones so they are just slightly less than half buried then pour on the crete.
the beauthy of these facing is the don't have to be super strong. You can use 80% peat if you want.

I use a simple chunk of 1.5 inch thick styrofoam with a 5"x10' rectangle cut into it for making these brick faces.
The beauty is you can add the brick to the back of these 'faces' any time in the future.
You could make a couple hundred brick faces during the winter and then come spring haul out the cement mixer and add the retaining wall backing with simple ready mix.

I can tell you this, none of your neighbors will have the same thing.
I have a friend in the US who is using my recipes to make a red white and blue retaining wall.

There is no reason the face has to be the same as the rest of the brick either. I've done a couple ovals that can attached to a rectangular body. It might look cool.

Hi Packrat

I did a wax cast of the face of a lava boulder.I got the body wax soft and just pressed it onto the stone.
I wet the boulder first and the wax peeled right off. It broke in chunks but reassembling it should be easy.
I haven't done anything with it yet. It's in my beer fridge to protect it from the summer heat.:)

I also did bark by covering it with handiwrap. I use the 18" wide rolls but dry cleaner bags would work.
I then pressed the very soft wax into the handiwrap.
It worked pretty good and I didn't lose that much detail.
The undercuts just bent out of the way but they are still there in the wax.
I will eventually go to work on this to restore the detail and try casting some faux bois.
The downside of wax is you won't get many castings, but the upside is $20 worth of wax can be used over and over.
AND unlike sillycone you can carve the wax and modify the casting as much as you like.

I love the wax but haven't done much with it this summer.
It doesn't work well in the sun.:) I'm saving my wax experiments for this winter.

Packrat,

When I took a artificial rock making class, we would cast rockfaces from latex, but Nofu's silicone stuff would work as well.

All you do is use a soft brush to get most of the loose dirt and small debris off of your chosen surface and paint on the mold-making material of your choice, being sure to really get lots of stuff in cracks and other detail areas. Build up several layers over voids that are wider than 1/8", this will let you really press the resulting projection into your casting material to get terrific depth and contour.

Let the first layer set up then put on at least one more layer before embedding burlap or some other strong fabric in the 2nd or 3rd fresh layer of your medium, letting the burlap extend past the edges of your mold. Apply at least one more layer of stuff of your choice over the burlap so it is firmly embedded; this is where the strength to keep your mold's integrity intact when you're pulling it off of a casting will come from.

Once the medium is set up fully, you can make a mothermold (if it's a large area) or just pull off a small mold right off the rock face. (this is never an easy task, especially if your rockface has lots of crevasses and cracks, but detail in the final mold is worth the effort) Don't worry if little pieces of the rockface are embedded in your mold. The first casting you do will remove them as they will become part of the casting. If you have rock embedded in a presspad, do a small casting of the area with the rock and it will pull right out of the mold when done.

Whether you are making a large pour mold or a smaller presspad, it's important that your edges are not rigidly defined. Feathered/ragged edges are what keep people from being able to tell that the surface you've textured is not real rock.

This also works great on trees!

Jo

Sillycone does work great on motorcycles too.
I watched a guy make a sillycone casting of a devils head on the side of a custom bike. It was that costly blue sillycone as well.
The problem for me is the cost. I can't afford to use the stuff. It doesn't get cheaper than $4 a tube here.
But for multiple castings sillycone is best.

Thanks for the ideas TE and Jo.

That rock making class must have been fun. Sounds like you didn't need much prep work for the latex. It may not have been necessary but I gave my rock a good scrubbing and coated it with Murphy's oil soap. After imbedding some nylon mesh with a couple more layers of silicone I peeled the patch off yesterday. Only a small amount of rock pieces stuck to it but it was still quite tacky. Maybe I didn't blot the soap off enough. I made sure to do thin layers and waited 24hrs between them. It's less sticky today but not nice and firm like the top layer. I didn't bother with adding acrylic paint to the 1st layer but did with the next 3. The edges are nicely feathered though. I'd like to attatch it around a 2" dowel and use it like a paint roller if it cures a bit more.

TE, tour brick faces sound neat but I'm definately looking to cast them in one shot. Guess the wax wouldn't be a good choice for this project. I did try casting on some 3/4" crushed stone and some woodchips covered with plastic but I didn't like the plastic bag lines around the indentations. Pea gravel would probably be better - it's probably smaller than what I used. Also using handi wrap instead of a garbage bag might make a difference. I haven't seen any 18' wide plastic wrap at the supermarket though.

I'm not looking fot a very pronounced texture for driveway pavers. I'm sort of going for the tumbled paver look and am also trying to incorperate rounded corners in the mold. If we weren't making so many I'd take a file to the edges but DH definately wouldn't go for that. I made a mold with 2x4's with mini blind slats glued around the top that worked OK but I don't know how well it will hold up with repeated castings.
I checked out the styrofoam at Home Depot - $12.98 for the 2'x8'x1.5" but they were out of stock.... wish they had it in smaller pieces so I could try it out before investing that much. There was a previous discussion about concrete sticking to various types of styrofoam but I can't find it. I think I remember you saying it doesn't stick to the kind you use. Is this correct or do you use a release agent ?

WOW, that is a lot of money for styrofoam.
I pay far less in Canada (around $8 Canadian) but I buy from an industrial supplier.
I only pay $11 for the really thick 2.5 inch stuff.
BTW that SINGLE sheet will make you a mold that will allow you to cast at least 8 4x12x12 bricks at once. The mold is reusable at least 100 times. That's 800 retaining wall bricks for your $13 investment. Wood molds will cost a lot more.

Concrete doesn't stick to blue styrofoam enought that you need release BUT use a vegi oil anyway.
The concrete does over time eat away at the styrofoam making it rough.
Oil will keep it smoth as a babies bottom.

packrat2

if you are up to your name, look around and you will find many different things for molds. I used styrofoam trays ( oroginaly meat was packed on it) for smaller stepping stones, just oiled it. For big ones flat cardboard boxes from Cosco or similar store, lined with plastic but put some sand around the edges and corners to have uneven natural look.You can build up texture with sand under the plastic too, sprinkle more sand on the plastic and cast the concrete on it. This takes away the shiny finish. For more natural look I sprinkle rock salt too, this washes out later, leaving nice sandstone effect.

Lawn fertilizer, those little beads, makes a cool finish as well when they dissolve away. Crete poured on a layer of straw is a great pattern.
There is no end to the ideas.

Tufaenough can you tell me where you are getting your styrofoam? It seems we have access to the same suppliers.

Another source (at least in southern PA) for styrofoam is the produce department of the local super market. Growers in CA ship grapes in them. The styrofoam is maybe an inch thick and measures about 16x20". They have a good deal of useable material. I get them for free, for the asking. If consumers don't ask and recycle them, they are fed to the large crushing machine affectionately dubbed "the goat".
spiderwoman

Concrete does stick to beaded white styrofoam BTW.
At least it does at my house.:)
But if you want to make troughs casting on the outside, the stuff used to pack small appliances like microwaves is just the perfect size and shape.
Covering it with plastic helps a great deal in getting the tufa off.