Sunday, May 10, 2009

building a papercrete wall

I've been building this wall (for months now?) using "slip forms" made from some plywood.

Saturday, May 9, 2009

a low rent papercrete mixer

This is a sort of low-rent papercrete mixer that does well for small volumes and might do ever better if I pulled it with my truck instead of my lawn mower. I actually tried it with the truck the first time I used it, but the truck is old and can't take the wear and tear--all that stopping and starting and rolling along at one or two miles per hour--so I just felt more comfortable pulling the mixer around with the lawn mower.
I call it low rent because, while most tow mixers involve some welding, this one is made primarily of a piece of fairly thick treated plywood I happened to have laying about from an earlier project.
Plywood was not my first choice. I'd been inspired by some guys online who'd made tow mixers out of the rear axels of trucks. One lucky guy in particular told a tale in which the junk man sold him the axel for $25 and, excited by the idea of papercrete, welded the hitch and other metal supports for nothing.

I didn't have that kind of luck. The junk yards around here wanted $150 for an axel whether I took it off or they did, and that didn't include the wheels or tires. I finally found one on Craig's List for $100 and the kid selling it threw in the wheels and tires, and I felt like I'd gotten a bargain.
So I took the axel along with a photo of a tow mixer and a drawing of the one I thought I'd like to make to some welding shops, and they were happy to do with work for what amounted to another $150. So...damn. I decided to try to make one out of the plywood and other crap I had laying around.
So far it's worked okay. Pulling it with the mower, it works best with one and a half 5-gallon buckets of wet shredded paper, 2/3 of a five gallon bucket of sand, 1/3 of a 5-gallon bucket of Portland cement, a little joint compound, and some boric acid. According to some of the large-scale papercrete projects I see online, that wouldn't amount to much, but this mixer works well for the smaller scale stuff I've been doing.
Considering my (lack of) mechanical aptitutde, it's a miracle it works at all, so I'm happy with it.
Since these photos were taken, I've cut the top third of the plastic barrel off, so that I can simply scoop the papercrete out of the top rather than using the "hatch" in back, which, incidentally, I cover with a piece of tin held in place by two bungies. I've also changed the blade. Orginally, I cut the blade too short, and wads of shredded paper would get stuck between the blade and the side of the barrel. I replaced the lawn mower blade, purchased for our old clunker of a mower that up and died before I ever got the new blade on, with the cutting end of an old sling blade.

Friday, May 1, 2009

Latex-cement skirting for mobile home

It cost about $600 for a guy to install vinyl skirting around our double-wide mobile home. Skirting is a requirement in our county. There was no concrete or other structures to deal with, so our job was a piece of cake for the guy, who just secured the lower track by pushing long nails into the dirt and secured the skirting up top with wood screws. Within the first few months we had covered holes made with our string trimmer with duct tape. Pretty soon there were too many holes to cover.
Then the high winds came and and beat the crap out of it--one side completely out of the track and pushed in under the house. I put it back in the track, but it was all bent up. It needed replacing.
I wanted something better. Brick, I was thinking. Or cement block.
I was intimidated by the cost.

I thought about some sort of stucco over metal lathe over plywood. It was the plywood that made me think I might be replacing that in 20 years. If I live another 20 years, I'll be 74. Nope. I wanted it all--inexpensive, nice looking, and durable.
So I was looking for an alternative.
I tried making some concrete panels, using so-called "crack resistant" concrete laced with fiberglass fibers. They were, of course, heavy and quite delicate.
It was a stupid idea.
Then I came across a formula for latex cement. The article stated they used a mixture of Portland cement, sand, and latex paint over nylon window screen to make roofs for shelters for refugees in some third world countries. The source indicated that, ten years after they were made, the roofs were still perfect, and appeared to be stable, and would probably last forever.
And that's when I decided to make my skirting out of latex cement.
I did only one end of the trailer as an experiment. I plan to do the front side of the home this summer, after I complete the papercrete wall I'm building.
This is a simple, relatively easy and inexpensive way to create skirting for a mobile home. You can probably come up with improvements to the process. If you do, let me know.
I cut "studs" from PVC pipe. These were two to three feet long, with a notch at the top so they could slip up under the little vinyl lip, and hole drilled through which to fasten in. I buried them four to six inches in the ground.
I attached nylon window screen to the pvc studs using little washerless screws. There might be a better way to do this.
The recipe for refugee roof latex cement is as follows;
First coat--
** one part latex paint (a "mistint" is about $5 a gallon if you have to buy it).
** one part water
** add Portland cement to make a paste-like slurry

Second and third coats:
** one part latex paint
** one part water
** then 3 parts sand to one part cement

Three coats dries to a hard shell.
Simply apply each coat with a brush after the previous coat dries. Three coats make a hard shell.
I had trouble attaching vents. The nylon window screen tends to sag with the weight of the first coat. Personally, I like the uneven finished surface, with it's bulges and sags, but it creates an uneven surface on which to attach the vents necessary to ventilate the crawl space.
I wound up cutting little frames for the vents from plywood, attaching them to the pvc pipe studs, and caulking behind them. These were rather cheesey black plastic vents purchased a few months back from Lowes with this very project in mind. I decorated them with some gold metallic spray paint, trying to simulate a sort of patina. I think a need I touch of green as well.
Anyway, cutting the frames from plywood gave me an idea of how to make my own vents.