$30 method to make compressed earth blocks (CEB).

I'd like to suggest using some type of metal hinge to attach the board your CEB sits on to the back end of the wooden mold and a latch on the front of the board and wooden mold. When finished pressing a CEB brick unlatch the bottom board at the front and press the brick through the mold. Perhaps onto a board that can be slid sideways past the CEB and on to making another CEB. And old door hinge would work I do believe. Just a suggestion.

Amedean,

Hey, I don't live that far away from you. Wondered if we might be able to get together one Saturday for coffee and talk about compressed earth block building. I'm trying to learn everything that I can in hopes of building a modest home in the Moore County area. I have high clay content ground on land that has been in my family since the early 1800's. Currently, my wife and I live between Siler City and Bennett but it has always been my dream to build back on the farm. At 44 years old, I have no desire to mortgage the land in a futile effort to build. I would prefer to build as time and money allowed in some way that allowed my son and I to bond over the toils of a long term sustainable project.

Any tips or insight that you gained during your project build would be greatly appreciated. I've sent you a private message that includes my e-mail and cell number. Look forward to hearing from you.

Sincerely,
Stephen

I built a CEB press to this specification, and have been having a lot of fun messing around with mud.

I have a few questions:

Is the two tons of pressure enough to make a really good brick? Most commercial rams generate much more, up to 30 tons.

How to fill the mold so exactly that all the bricks are the same size, while still keeping the process relatively quick?

What are the bricks supposed to be like when they come out? I was surprised at how soft they were. Various sites talk about building with them straight out of the press. Does the strength only develop with drying/ curing?

I built a mold like Amedean's second attempt. I fond that propping the mold up on two pieces of wood made it easy to use the press to push out the brick. I think this would be more time efficient than having an inner liner to reassemble after every brick. However, the pressure split a two by four and bent a bolt in the mold, wrecking it for the time being.

Gilbert Fritz wrote:
Is the two tons of pressure enough to make a really good brick? Most commercial rams generate much more, up to 30 tons.

Thats a really good question. The best that I can answer is that I think it really depends on what it is used for. Commercial rams produce a better brick because they have higher compressive forces. With that said, I think a good CEB press design can be constructed from a wooden structure. When I first decided on working on a wooden block press I wanted to mostly apply a theory and I did succeed to a degree. I think my original design needs an overhaul after I made dozens of bricks I noticed structural wear. This may be something I will look into in the future for a fun garage project when I have more free time.

Gilbert Fritz wrote:How to fill the mold so exactly that all the bricks are the same size, while still keeping the process relatively quick?

I did this by hand and my bricks were marginally variable. It was repetitive but at the time I would press the subsoil and fill it until there was satisfactory depth.

Gilbert Fritz wrote:What are the bricks supposed to be like when they come out? I was surprised at how soft they were. Various sites talk about building with them straight out of the press. Does the strength only develop with drying/ curing?

I suspect water saturation has a lot to do with this. I am a pretty heavy guy and my first blocks supported my bodyweight when I rolled my feet. I used my subsoil which seemed to strike the right balance. Another time I added water to the clay subsoil and the bricks did not hold shape when I stepped on one. Also, in order for the bricks to become weatherized they need to be "stabilized". I think concrete or another stabilizer is used in small quantities as a percent weight of clay I imagine you can Google. The number escapes me at the moment. Its a very tedious process which I have not formed a solution yet to simplify and make it less laborious.

In another subject, I think you should also investigate rammed earth for something on the cheap. There is a thread here:

https://permies.com/t/33925/cob/Cheaper-easier-rammed-earth-technique

Lots of good info in this thread and others here in Permies.

Well, I am still working on developing this further. All my bricks have been really soft right out of the press, but have become quite hard with time (even the ones without cement.) My soil does not have much sand in it, so I bought some and added it, which made things less sticky.

To solve the mold breakage problem, I added metal angles to the corners, in addition to the bolts. Now I am trying to make a better "plunger" for the mold. My current one tips sideways, making an angled brick, and also lets the mix form ridges around the edge.

Do you think one of these could be built out of steel angles and threaded rods? This would be more expensive, but sturdier. And it still would not require welding, which most people can't do.

Still interested in this. My press developed enough pressure to damage its self and destroy or jam up molds, but not enough to make a satisfactory brick. They dissolved when I put them in water, even though I used five percent cement. I am sure I could have used them to build a weather protected wall, but I would like something a little more solid. Also, the brick without cement was quite weak, and the whole process was very fiddly. I couldn't make many bricks an hour, and they had to be babied out of the mold and into a curing stack. Most of them broke in the process while they were still soft.

I want to keep working with this. Instead of using all wood, I am going to change the original goal. My goal is now to build only with materials that I could potentially find as scrap, plus hardware, and without any welding. (Welding is the big problem with the CINVA ram from somebody like myself.) So metal pipes will be usable for some of the parts. Also thicker bolts will be a big help. I will be lengthening the top lever and adding a counterweight to add more pressure, keeping bricks together better right out of the mold.

Do you suppose ferro-cement would make a durable mold?

I have watched your thread with great interest - I have posted a few on this forum myself. Has anyone looked into - or heard of - anyone making very large bricks out of rammed earth? By large I am thinking 3'x20"x20" (approximately 90cm x 50cm x 50xm) My reason for such large bricks - it would make it very easy and quick to put a house - or any other structure together, although it would require the use of a forklift. Also, the place where I am going to buy land gets rain about 150 days a year, so fast construction time would be very helpful. Any ideas?

imagine the force i'd require to compress such big lump of dirt uniformly.

Anyone have any experience with these Columbian CEB makers: http://www.gracomaq.net/index_archivos/gracoramenglish.htm
They've got neat plans availible too.

I know you want to keep your press cheap, but this thread here:

https://permies.com/t/33406/built-Cinva-Ram-CEB-press

details a man building a known press schematic out of steel, and has offered the plans and pricing up to the group - even if you don't end up going with the plans, they could be inspirational for your own?

This is a really cool idea! Thanks for sharing! ....and bringing this back up dustin! If anyone is still looking for a way to stabilize the blocks lime works and is more environmentally friendly than cement.

I manufacture the Dalrac Mudbrick Press in Australia. Its a CEB machine made from steel.
I like your design for something really accessible.
Can I suggest having a slight taper on all sides of on the mould so the block can more easily drop out.
Also, consider lining it with tin plate, that may also help.

Amedean Messan wrote:I have been working for a few days on a project to construct a highly affordable method for manufacturing a CEB.  If you are familiar with CEB construction than you understand that these machines can be incredibly costly which limits use.  I wanted to have the option for making CEB for retaining walls or raised bed gardens so I did some research on making something good enough and affordable for those small projects.  So far I am almost finished with my design but I hit a snag with the block mold.   I did the press in Solidworks below.

The press should generate over two tons of force.  I decided to go to Lowe's Home Improvement today and spent a little over 30 dollars in materials to construct the press.  There is about 9 inches of clearance from the base to the contact board where the force is directed.

Again, the compressive force from the press pulled out the screws from the wood easily when I tried to form a block from clay soil.  I wish I took a picture of the block I made but it clearly had enough compression to harden significantly which proves the viability of this economical method for constructing CEB.  Here is the very basic mold I constructed.

SO this leaves me with the final design challenge which will require me to construct a mold which can be withstand the compressive forces applied by the press.  I will also have to look into making an efficient process to extract the block from the mold.  Obviously when the dirt is compressed it creates increased friction along the walls so in the next few days I will potentially have the mold constructed of two pieces - the outer wall to confine the internal stresses and an inner wall which will allow me to extract the block.

We have constructed a guest house with CEB and used a substantial stone foundation to protect the blocks from rain & water. I really can’t picture how you can use these for raised garden beds?

I'm aware this post is an old one, but I've had an idea for years of how to easily fix this. A fat 50 Cal ammo can is about the right size for a decent block, is already welded square, and has the plenty of height to leave room for a Lego block plate to stack them. Take out the bottom,  use a hole saw on the plate and a wood block on the other side with the circles you cut out, and you have Lego plates. If there's problems with the difference in size of holes and pegs, you can use washers with narrow holes the right size. It would double the cost at $26 for the fat 50 and who knows the amount to make the press bigger, but would produce bigger and much better blocks.

To get proper CEB compression you need materials with sufficient water. Depending on the soil 600 psi compression can yield 2000 psi finished material. Inverse, 5000 psi compression on insufficient wet materials will result in a 30 psi break. Labs can do soil compression testing that will give how much water is needed as a percentage of the soil. The test run about $150. You can do several test blocks instead using a 7 day to break. Put the CEB on a sturdy table, lightly score the block about half way. Hit it sharply with a hammer. It should break clean, not crumble, along the score line.