Some Help from a Friend

Many thanks to Nathalie from BC for ALL the help during her visit. Besides providing first rate support making blocks she also brought with her a water purification unit. With this important piece we can now check off the 'water' in the 'food, water, shelter' list. She also brought a great variety of heirloom seeds so we can improve on the 'food' goal.

Scouting Mission to Ometepe

Thinking we may want to start building on Ometepe we decided to go on a little scouting mission. The island was everything we had hoped in terms of potentially doing a small development with the blocks and renewable energy. We liked what we saw and will be moving toward the island with the project.

Another Roof Section Added

Here you see another section of zinc roof added on to the front. This was the first of two expansions to allow us more dry space to work under when it's raining.

Making Blocks in the Rain

This was our first attempt at making blocks while it was actually raining. It's very important that we are able to keep production going while it's raining so that we don't lose time during the rainy season (about 7 months). We could obviously still use a larger space but will have to add-on as resources allow. The rain was unusually strong. It flooded town and turned the farm into a lake for a few hours. We were forced to pause the block making while we built a quick berm around the work area. This was enough to prevent the water from coming in and allow us to keep working.

Roof Added in Front

We've added a 12'x12' zinc roof section on the front of the bodega so as to have a larger dry working area. Hopefully we'll be in regular production soon. I have also installed a small solar system, a 3mb/s internet connection, a toilet and a desk. The bodega is much more agreeable now. I'm happy to say this is the first blog update from the bodega with many more to come. I'm working on a few different paths to getting some soil trucked in. The rainy season makes it more challenging.

Milestone Complete: Construct Demonstration Unit

And there it is...Our first CEB structure. We now have a bodega and will be expanding as resources allow. I have to thank my friend from Colorado who came down for three months to help me build this. Making the blocks was a group effort but the actual construction was done by two guys and very basic hand tools. Without the help of J from CO it would not have been possible to do this year. Waiting until next year would have been a big bummer so it's really great to get our rainy season test underway. Future direction will involve testing various new techniques such as lime plasters and arches and ramping up steady block production.

Presenting the Screen-O-Matic 2000!

Total materials cost was around $50. We needed a screen that was purpose built for CEB needs. For us this meant portable, low cost, manual powered and a significant improvement over the way we have been doing it with smaller two-person screens. With the previous method 5 guys produced enough soil in one day to make about 100 blocks. With this new tool one guy can produce that much.

Still More Detail...

Top photo shows how we decided to put in the lintel for a door. We left loose half blocks in place when we poured the columns and later removed them and put the 4x4 in. We did have to chisel some out on one side still and then back fill it with mortar mix.
In the second photo you can see where we stopped the stucco and the 'espera' for the iron gate. It's sunk into the poured column behind it. We deliberately left the inside of the wall unfinished for demonstration purposes.
Next you can see the basic roof technique and the finished stucco (still drying). If you're wondering what the two pieces of zinc below the main level of the roof are for, it's just where we decided to store the extra pieces we had :-)

More Details on the Techniques

Here you can see more of the bonding techniques. The top photo shows a close up of the wall with the mortar joints. The color is from a basic broom wash that was done as it was being laid up. Next photo shows where we have started the stucco (repaya). In the bottom photo you can see how the formed column at the end of the wall is used to join the CEB wall to the pre-existing brick/cement wall. The blue color on the existing wall is old paint. The darker blue color on the concrete column is a bonding agent (plastibond) we were testing.

Our First Building

I love tests that might also have a practical use. As long as your planning takes into account that it's just a test (and dependencies are mitigated) any benefit derived is just gravy. Therefore, we thought a bodega would be a great first building project since we needed somewhere to put our stuff and it incorporates numerous conventional construction techniques that we wanted to experiment with.
The most critical test of all is the water/weather proofing. The rainy season in Nicaragua is torrential and will be the biggest challenge we will likely have as far as the CEB process goes. In that regard we needed to test techniques for the footer, roof and stucco. Ideally we wanted to go with a lime stucco but learned too late in the project that the lime needed to hydrate for a longer time than we had. To compensate we went with a standard masonry stucco using 6:1:1, fine sand, lime, cement. You can see we used cut stones (about $1.50/each) for the footer on top of an existing slab. This got us a foot off the ground and is working well so far. The roof could use more overhang but still is giving the coverage needed. We used all plain blocks bonded with a standard masonry mix.

An Odd Atmospheric Display

The day of this photo (Mid May) we got to see an unusual halo effect around the sun.

A Change of Plans

We started with the intention of doing a completely new structure. The plan was for a round room of about 12 feet with a concrete/rebar footer and a poured concrete/rebar slab roof. While we still love the idea we realized that we weren't going to have the resources to pull it off before the rains started (time and money being the constraints) so we changed tack and decided to go with the original plan which was to build off an existing structure, a brick outhouse. We had a pretty good design worked out for the round room and were excited about doing it but it was just too ambitious for the first room in a number of ways. In hindsight it was much better to simply extend off the front of the outhouse as it put us back in a realistic time/money budget and also allowed us to test basic construction techniques without too much risk exposure.

Yet More Blocks

We realized it was going to take a few more blocks to get the bodega done so we got busy. It is so nice to see the stack grow.

After a long time with no updates...

I have been remiss in updating in regards to the progress of things, I know. We have been in a race against the rainy season. Since the last posting we have been working on the first building (a bodega) made with the blocks in the previous photos. The rainy season starts in Nicaragua around the middle of May (give or take a few weeks) and we had to get the roof on the bodega before then. Two days before the rains started we finished the roof. Now that the time pressure is off I can finally bring the history up to date.

The Stockpile Grows

This is about 200 blocks. You can sort of visualize the size a wall of 100 blocks might be. There are obviously some less than perfect ones in the pile but for the bodega they don't have to be pretty, just structurally sound. Any blocks that don't make the cut will get thrown out at build time.

Testing the Different Block Molds

We spent a full day testing the various molds I purchased with the machine. This was the first time for anything other than the lego mold. We also spent some time getting to know the machines fine tuning. We've been having problems with some of the soil sticking to the bottom mold along the edges. When you lift the block a chunk of it is still stuck to the mold and of course leaves a proportional sized chunk out of your block. Not cool...This only happens about 20% of the time and we didn't have the same problem with the first soil we used. We spent a fair amount of time on our first full production day tweaking the compression, the moisture of the mix and even varying the use of oil on the mold. We could never seem to eliminate the occasional stuck block. So, today we checked the plate risers for the bottom mold and also made sure all the screws for the molds were tight. We also took the opportunity to try out all of the molds. Here are a few of the things we learned;

• There are 6 large bolts on the bottom press plate. At first I had no idea what they were for as they were not actually touching the lego bottom mold, screwed down to below flush. I realized what they do when we started testing the half block molds. There's a partition in the middle of the half block molds which needs to touch exactly with the top plate in the closed position. You can use the risers to adjust the height of the bottom mold plate in the box relative to the top. Once it's set just right then it 'cuts' the block for you. Too high and the top plate hits it (and could damage it), too low and the block doesn't get cut properly.
• The lego half block mold had the same sticking problem as the full lego mold
• The plain blocks came out perfect every time
• Considering the time it takes to really get the machine set just right after changing the molds you don't want to do it too often. It doesn't take too long but will impact production so maybe once per day at most.
• We think after further examination of the sticking problem that the new soil is a little too fine to work well with the lego mold. Rather than try to doctor the soil to be of use with the lego mold we're going to go full steam ahead with the plain blocks so we can get the bodega done.
• The Roman arch mold works great. We'll definitely be making bunches of those.
  

Our First Drop Test

This is our first drop test. The block is a 10% cement mix using the soil from our second excavation site. As we're still pretty new at this we were pretty happy with the results. The block had only 1 1/2 weeks cure time so it was not even ready yet, but we wanted to know what it was really all about so we sacrificed one.

Our First Full Production Run

Today we did a full eight hours of nothing but making blocks with the screened soil from the previous week and a half. We're sticking with the 10% cement mix and trying to get enough blocks to build build the bodega as our production target. I can build it with as few as 500 but may go bigger depending on how many we come out with. The total made for the day was 135. We spent lots of time tweaking the compression on the press and the water mix trying to get it just right so we feel that once those things are worked out we should be able to get up to 300 a day. It's a good goal for now.

Big Pile of Screened Soil (yay!!!)

So, 5 guys screening for 8 days makes a pile of screened soil this big (the lighter colored soil on the right hand side). Just a guess but it looks like enough for about 800 blocks.

Our Second Excavation Site

And we like this new soil so much more...I'm proud that we have been able to make good blocks with the soil I had available at my site but we knew there had to be better soil in the area. One of the CEB books I've read suggested that to find the best soil you should talk to the traditional brick makers, as they would know. Lucky for me my neighbor is a brick maker. I'm going to go into a bit of detail here because this little story is integral to my aspirations for the project. I'm very wary of unintended consequences so as I move this project forward with the intention of creating some new entrepreneurial opportunities I didn't want to hurt existing markets (traditional bricks). To avoid this dilemma I decided to introduce the idea first to the brick makers as an addition to their business, not competition. Hopefully this will result in a significant net sum gain. So, all that being said I was really hoping to catch my neighbors interest in the project and let him come to his own terms as to how he might see himself fitting into it. This is a family actually. The father still makes bricks and his sons help and as these things go the sons are becoming progressively more in control of the daily processes as the business gets passed to the next generation. Both of his sons are helping with the CEB project with the eldest having worked his way purely by merit and enthusiasm into the supervisor position. Both of the sons have told me on numerous occasions that making CEBs is much easier than making bricks. So, in short, the Dad flat out said to us "you can never make blocks like this" before he saw the press. He changed his mind the first time I put one of the blocks in his hands. Little by little his interest increased and about a week and a half ago he offered to let me use some of the soil from his property as he thought it would be better to work with. Thankfully, he was right. The new site is only about 50 yards away but the difference in the effort required to screen the soil is like night and day. The quality of the blocks is much better as well. So, we got busy screening soil and kept going until we had a substantial pile ready to make blocks. You can see the first blocks we made with this new soil, 10% cement mix and a little more water than we used with the last soil. I intend to work out an arrangement with the Dad to use more soil and pay a certain price per block made. It needs to be priced like this so that a static price can be calculated for clients. I'll be documenting more of the business model soon as the details are starting to emerge.

The First Practical Application

I wanted to grill out for New Year's Eve but didn't have a grill! Well, I had the grill grate but not the rest of it. I realized I could use some of my new blocks to make it happen and Bam!, chicken...It only took five minutes to assemble and I can move or reconfigure it as needed (no mortar). Myself and guests were all impressed at how well the blocks shielded the heat from the coals. The outside of the blocks at the hottest places were still completely cool to the touch. Actually cooler than the ambient air temp, amazing.

2 Weeks of Curing

The second round of testing has now been curing for about two weeks and everything seems to be going well. As you can see the blocks are still looking good and are starting to dry enough that the final natural color is starting to emerge.