Re: [papercreters] Re: Rapidset cements and papercrete

Hi,

 thankyou for that information. how i wish there were a Granicrete distributor in Oz-their website has a section where

people can apply to do so, maybe someone will? Or just cheap transport from Queensland to Tasmania then i can 

concoct the formula myself. Dead Burned fine ground MgO is a dollar a ton oif you buy 40 tons of it-$125 per 20 k otherwise

and $400 quoted for shipping!

the rapidset 60, as well as stinking and being to expensive, is an ugly dark  steely grey colour and the aggregate,

which it comes premixed with, gives the surface a lumpy appearance which does not enhance it-

 i was after a smooth white marbley surface so you can imagine my dissappointment!

. i fear for the 'raft' of rapidset that is the core of the sculpture's plinth-guess we shall see how it goes.

 i am now contemplating some sort of waterproofing on the sculpture to protect the rapidset 60,

how crazy is that when it was supposed to be a bombproof support for the rest of it!

Given that above the 'splash line' i used some paper in the mix,i am not sure if that is a good idea as it would seal water

in...sigh. design conflict brewing.

cheers, eo

On Tue, Feb 19, 2013 at 11:13 AM, zenseeker70 <mrinnovation@frontiernet.net> wrote:

 

Ah, ok. Different formulation than we have here in the U.S. The Calcium based stuff is made in China and imported for Home Depot, Lowes and other home improvement stores. I guess down in Oz they are making their own formula based on Magnesium. The Ammonia based cement is not the best type. I'm surprised they are making that formula.

The Mg based cements with Ammonia have water absorption problems and are not to be used in wet environments without sealing. They cannot be used underwater like other formula's either. And like you said they give off Ammonia gas while they cure. It appears to me after some research that the only attractive formula is Mgo using Mg Phosphates for the reaction. All formula's however do bond well with paper and other fibers. Far better bonding strength than Portland.

Tad

--- In papercreters@yahoogroups.com, eo greensticks wrote:
>
> hi,
>

> the rapidset concrete i used was Rapidset *60* and it said on the front of

> the bag that it was mag phos cement based- it definitely
>
> had ammonium something in it- hopefully not ammonium sulfate bit rather
> ammonium phosphate-unpleasant smell and generally
>
> unpleasant as well as expensive. i tried to look at the information sheet
> to see what else was in it but you had to register and i got
>
> an error page. i gave up then as i wouldn't wish to use it again. i just
> hope it holds as the $80 core of the plinth for my current
>
> sculpture as a retrofit would be quite impossible!
>
> cheers, eo
>
> On Sun, Feb 17, 2013 at 10:20 PM, zenseeker70

> wrote:
>
> > **

> >
> >
> > Hi,
> >
> > It looks like the rapidset cements are actually Calcium Sulfoaluminate
> > Cement and not MgO based. If this is the case then Rapidset should react
> > with Zinc coatings, but I have not heard of MgO not being compatible with
> > chicken wire and other galvanized coatings. Calcium Sulfoaluminate Cements
> > also reach a high early strength similar to MgO and should be compatible
> > with paper fibers as well. Might be worth a try.
> >
> > http://www.ctscement.com/Cement_MSDS.asp
> >
> > Tad
> >
> >
> >
>

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