[papercreters] Re: Papercrete as growing medium

Thanks for the additional info. Your goal is much more clear now.

You talk about the need for light weight. I don't see how a 10" diameter 5' high pole will be lightweight when it gets saturated or wicks up hydroponic fluid. The water weight will be far greater than the weight of the paper.

I would encourage you to consider not using cement at all. Just make a paper only slurry, drain it on a screen, and COMPRESS it with as much pressure as you can muster into your pole shape. You'll be surprised how strong highly compressed paper pulp will become.

Just to be clear, I'm not talking about just pushing on the pulp with your hands to squeeze it with a few pounds of pressure. I'm suggesting using something like a 10 ton hydraulic bottle jack. (They are extremely inexpensive. You may already own one.) If you created a form that could withstand that kind of pressure and compressed damp paper pulp with a few tons of pressure, it may be strong enough for your needs.

Almost all of your expense would be in building your high pressure reusable form that will still allow water to drain out of the paper as it gets compressed. I would suggest checking at your local junkyard for steel pipe that is 10" diameter or so, and they trying to build a cap on one end, and a "piston" that can get compressed by a bottle jack into that pipe to squish the paper pulp. The piston need not be a perfect fit, since you'll need to allow water to drain away as the pulp gets compressed.

You should almost be able to turn scrap paper back into logs of wood with such a device.

Of course, without anything added to the paper, those logs will mold easily and have practically zero tensile strength, particularly when damp.

Before investing time and money in the big fancy pipe and piston, I suggest experimenting in a small scale using whatever scraps you have laying around and with whatever jack or other compression device you already have. Then you'll start to get a feel for what compression can really do to damp paper pulp.


You may or may not find these thoughts helpful, but perhaps there are some ideas in there that will inspire you to find a solution you like that works for your situation. Feel free to try whatever variations make sense to you.

Please post updates and photos as your project progresses.

--- In papercreters@yahoogroups.com, "prrr.t21@..." <prrr@...> wrote:
>
> Many questions here, so I'll explain.
>
> The idea is to make a vertical rod of weak papercrete or similar, and put several food producing plants into it. The reasons for papercrete or pulp are that it can be made out of garbage - cost is critical - and its light, enabling it to be moved twice a day, which will be needed. Paper of course offers no nutrients, so basic hydroponics will be used, basic meaning no nutrient testing involved, and just partial reuse of the water given to the plants.
>
> Composting isn't that practical, it would greatly reduce the amount of soil replacement material, make it much heavier and take a long time to deploy. The idea is to make the soil replacement lightweight to enable moving lots of these things about daily. They'll never be planted in the ground.
>
> Is cement papercrete safe to grow food crops in? I assumed not due to chromium. If it is, the question would be solved. Biodegradability isn't an issue.
>
> Re water evaporation, I was thinking the cheapest option would be to wrap the pole in polythene, or perhaps clingfilm.
>
> Dimensions aren't yet decided, but as a starting point something like 10" diameter 5' high. There would probably be a wood stake up the centre for support.
>
>
> thanks
>
>
>
> --- In papercreters@yahoogroups.com, "JayH" <slurryguy@> wrote:
> >
> >
> > Please provide more details.
>




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