Re: [papercreters] Question about the ceramicrete.

Hi,

you cannot combine Magnesium phosphate cement with portlkand as the phosphate doesn't 'get along' with

lime. you cab substitute a different sort of magnesium, MgO that is the reactive sort

 (  it has a cow on the bag and is sold throo agricultural supplies dead burned MgO is not reactive)

for part of the portland but

this will not make a chemically bonded ceramic, will only make the cement stronger as i understand- see TecEco's website

where they discuss this at length.

Magnesium phosphate cement is marketed as Granicrete in the USA  and the company runs training sessions in how to use it

but i haven't been able to get any to try as i live in Tasmania.

 i have at last found a supplier for the fine ground dead burned MagO- they are  in Queensland but at $250 for 40k and a $400 freight

 cost to get ti to Tas,it isn't looking good yet! 

At this stage i am thinking it would be best as thin shell walls rendered with papercrete to get to the R value

thickness or else as a render over regular papercretewalls  to keep the water off it? .

If it could be worked out, i doubt an insect could eat papercrete if it was made with successful chemically bonded ceramic?

It seems that the dead burned MgO must be fine ground- a fellow called Leo Freeman has some Utube videos of experiments

where he tries to make Ceramicrete (MgPO4 concrete) with what looks a coarse sand textured dead burned MgO and it doesn't

 really work (that is, the one test that set up was easily marked and easily broken...) but maybe he has done some further

 experimentation by now and achieved a better result? He is using properly weighed samples- the MgO must be in the right

 proportion to the PO4 with the right amount of water for the reaction to occurr 

 AND i noticed in the link to

 Argonne's tests, they reckon it must be stirred for an HOUR (don't even know if my drill battery lasts an hour?)

they were using it to patch holes in a runway and on a boatramp, also making cast beams i think

but  they had one episode where the stuff 'flash set' for some reason so i wouldn't use it in a mixer just in case.

One part worried me a little, where they said they used vinegar (acetic acid) to clean the MgPO4 off their tools-

i would prefer a finished result that was vinegar proof somehow!

Charmaine says Michael Collins used in on burlap spraying or brooming on the slurry but how it didn't set up and ruin the sprayer is 

not clear.

 I think  it is worth exploring because, as you say, it would overcome some of the limitations of papercrete.

We get alot of rain where i live so susceptibility to water is an issue.

I have tried some papercrete plant pots with portland and reactive MgO (the kind with the cow on the bag)

 at a ratio of 2 parts PC to  1 part MgO for the cement

part of the papercrete mix.

they took quite some time to achieve a strong surface but have weathered well (they are 2 years old now)

As they are plant pots, they are always wet-but i have not been able to draw any conclusion about whether

the MgO improved the papercrete or not....

With even a small proportion of MgO in concrete, a slab will not drain the charge from a battery like a straight portland slab would-

i just found that-it has different electrical conduction properties.

How i wonder what the recipe was for the papercrete walls  built in the humid south of the US which were unprotected and showed

 no sign of deterioration

after many years?

cheers, eo

On Mon, Feb 4, 2013 at 4:47 PM, babalubird <losee04@sprintpcs.com> wrote:

 

Sounds like it could be an answer to some of the papercrete problems. Fascinating!

Since you can mix the magnesium-based cement with fiber, then can I assume you could just substitute this for the little bit of portland in the papercrete mix? Would you then wind up with a stronger, water-resistant material as described for the nornal ceramicrete?

Would you still need the sand and lime in the mix or would just a large amount of paper and a minimum amount of the Mg cement give a strong, thinner-walled, insect-proof material?

Has anyone yet found a source of this magnesium concrete for us average Joe's and Jill's?

Thanks.

Connie

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