Hi,
Eo,
The "batteries on concrete" myth got started in the early days of the automobile - think Model T. At that time, the container parts of batteries were made from wood. The thinking was that the moisture in the case would conduct electricity to the moisture in the concrete and drain the battery. Today, battery cases are made from plastic, so I do not think this is a real problem.
(Restorers of brass era cars - I don't know if the original myth was true.)
Bobby
--- In papercreters@yahoogroups.com, eo greensticks wrote:
>
> Hi,
>
> i have been using the ferrocement technique for sculpture and one of the
> reasons i was interested in MgO was the different electrical
> characteristics of the MgOPO4 concrete...
>
> the 'flaw' in ferrocement is that if you are using chickenwire with
> galvanized coating (zinc)
> i understand that there is an electrical interaction in between the zinc
> and the portland concrete which will eventually deteriorate the
> sculpture.Portland and copper don't get along either apparently.
>
> maybe the MgOPO4 over the chicken wire Might eliminate this problem, does
> anyone know?
>
> what i thought was to then use the papercrete as the *top* layer (the other
> way around to the suggestion)- it would absorb water of course
> (small test piece indicates that it absorbs an approximate third of its
> weight in water-hopefully not too much for the engineering of the frame?)
> but the water would then be released back into the atmosphere from that top
> layer - Would that work?
>
> I would *rather* use the MgOPO4 in the papercrete so that it was
> 'everything proof' ( all fibre encased in chemically bonded ceramic sounds
> great!) but
> i am still trying to find a source of the raw ingredients at an affordable
> price-
> it seems that the Granicrete is fairly expensive as well-i would be using
> it to test if i could get any
> but no australian supplier yet.
>
> i read Somewhere that even a small percentage of MgO in concrete mix for a
> slab means that a
> battery left overnight on the slab will not be discharged (i did not know a
> battery left on a concrete slab overnight Would be discharged but there you
> go)
>
> I have tried using MgO, the reactive kind with the cow on the bag, in the
> portland mix for ferrocement over galv chicken wire at 2 parts (by
> volume!) MgO to 1 part Portland and also the other was around (2 parts
> portland to 1 part MgO, by volume again) but hard to say what the
> difference is and i will not be here in 500 years to know if it failed! So
> far, after 2 years it seems fine...
>
> This would Not , of course, be the chemically bonded ceramic that seems to
> have become my 'holy grail' but i was going on the formula reccommended by
> TecEco to the sculptor in west australia who made the beautiful giant
> Ghekko sculpture (i think he also used flyash and
> clinoptilolite in his formula though which i did not)
>
> I am starting a new sculpture now, having just completed the chickenwire
> armature-having failed
> to find a source of the dead burned MgO i will use portland but thinking
> about coating the wire with something to isolate it from the portland-i may
> use reactive MgO in the portland mix for what it's worth but as i said, do
> not know if that will mitigate the 'electrical' deterioration of the
> material.
>
> Does anyone have any ideas about this?
>
> PS: at the risk of being longwinded (!) i attended a wooden Boat Festival
> yesterday where they
>
> were making boats with heat shrinkable dacron over cane or wood
> frames-very lightweight-
>
> brought me back to thinking about the patio roof i have been ruminating
>
> on for some time- my latest idea had been a lightweight sapling frame with
> rope or wire (or
>
> cane?) between the larger woods (which turned out to be exactly how they do
> the boats!)
>
> i would then 'skin' this frame (like the boats) with cloth stretched
> tight onto it and then paint
>
> with bondcrete -this would become the interior surface-and would provide a
> stiff enough
>
> support capable of holding the weight of a second layer of cloth dipped in
>
> slurry without any sagging , a design problem which has dogged my previous
> efforts at 'roof'
>
> (oh, for the MgOPO4-but i would use PC for availability just to get it
> done and keep the
>
> patio from being washed away by these crazy rains!)
>
> The idea is that i could work in courses from the edge to the top so that
> each completed
>
> section would hold my weight to continue the process (i would probably use
> removable supports
>
> to be on the safe side...) resulting , if it works, in a curving organic
> sort of roof shaped so as to
>
> shed the water to where i can collect it ..
>
> I go around about whether it should then be rendered over or perhaps a
> renderish layer
>
> of..papercrete? sawdustcrete? something...?* between* the cloth layers-
> maybe not necessary
>
> for strength but better for some insulation (my unlined tin roofs 'rain'
> inside from condensation on
>
> cold mornings, not good!)and then some kind of waterproofing safe for water
> collection over the
>
> top.
>
> Obviously the MgOPO4 is still the perfect but so far unobtainable solution
> to this design
>
> possibility but from what i have done so far and what i saw at the boat
> festival, i think it may
>
> work.
>
> there may be some 'tie down' issues to keep the thing
>
> on site (!) but it had me surmising that an upturned boat may have been
> 'the primordial roof'?
>
> cheers, eo
>
>
> On Sun, Feb 10, 2013 at 9:45 AM, seniorfinancialplanningins <
> devonia111@...> wrote:
>
> > **
> >
> >
> > *MgO i*s used as an insulator in industrial cables, as a basic refractory
> > material for crucibles and as a principal fireproofing ingredient in
> > construction materials.
> >
> > *From:* Garth & Kim Travis
> > *To:* papercreters@yahoogroups.com
> > *Sent:* Sunday, February 10, 2013 7:26 AM
> > *Subject:* Re: [papercreters] just wondering
> > **
> >
> > Greetings,
> > What is MgO?
> >
> > Bright Blessings,
> > Garth & Kim Travis
> > http://www.therosecoloredforest.com/
> >
> > Bedias, Texas
> >
> > On 2/9/2013 10:59 PM, devonias wrote:
> > > I was thinking of you using papercrete on a small chicken wire structure
> > > then covering it with MgO...can you shoot MgO from a heavy duty shop vac?
> > >
> > > _
> > ****
> >
> >
> >
>
__._,_.___
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
__,_._,___
