This was the hardest part of the entire project so far – it was my first attempt at working with cement (other than using a couple bags of ready mix to set fence poles). To make matters worse, We were being filmed by a crew from Doomsday Preppers so we were on an extreme time limit (basically we had one day to do all the cement work), I only had one helper (Thanks Dad), and my mixer kept breaking.
All in all, I am pleased with the outcome, and learned a lot about what to do, what not to do, and how I would do it if I ever do it again….
What we did up to this point was to build out dome and frame in the door. Now we have to prepare for the cement.
Our intent is to cover the dome using a concept called ferro-cement (FC). In ferro-cement you don’t have to use as much cement to cover a structure because you are using more structural wire – the ideal is chicken wire every ¼ inch or stucco mesh.
In most instances of using FC workers use a thick mix of Portland cement and sand 1/3 ratio, and work against each other to press a low slump (little water) mix against the wire. Continue reading
When figuring out the door I got the basic idea from my test build in my front yard, but when my Dad came to help me build the actual cement dome he brought a lifetime of construction experience that I just don’t have.
We fiddled around and came up with an idea that I am very happy with, but due to the time constraints of the film crew we did not write down any measurements, and I could not take video of it.
However, with the pictures I made on the computer and the experience you will have building the dome, I am sure you can figure it out.
Besides the dome itself, you will need one of the extra 4.3 foot struts, some plumber strap, some nails, and 2×6 boards for the door frame. Continue reading
I spend a lot of time looking at appropriate technologies coming from missionaries and other groups that work in third world countries. I figure – if it works in areas lacking infrastructure then it will work if we ever lose our infrastructure.
This idea came from a couple of YouTube videos I saw of people making skylights out of 20oz soda bottles. Most specifically this one.
I modified it slightly and was quite pleased that two of them gave enough light in my cement dome that I can see what I am doing – actually, if I am in the general area of one of the lights I can actually read by the light. Continue reading
When I made my first dome I found the websites Mike’s Spacetime and Desert Domes to be the most help – Desert Domes in calculating the strut length and Mike’s Spacetime for his diagram of the struts assembled.
He used the colors blue and red for his – but I used White and Black for my struts because the paint was several dollars cheaper. For my assembly diagram I used black and green since white doesn’t show up very well on a white background… Continue reading
There are many ways you can flatten the strut ends – hammer them, use a large shop vice (reportedly this is destructive to the vice) or use a hydraulic press. It took me so long to start this project, as I was saving up for a 12 ton shop press specifically for this project.
I used a sawhorse to set my 2×4 jig parallel to the ground – with one end under the end of the press.
I modified my jig and thinned down one end about 4.1 inches from the stop – this allowed me to place one arbor plate on the 2×4 and line up one end of the plate with the line I marked 1.5 inches from the end – that way, each pipe was smashed the exact same amount. – using the arbor plate also allowed me to smash the end with a curve – instead of straight across – making each end stronger. Continue reading