Cast Stone Formula?
Gary Waller
"Raymond" <nom...@att.net> wrote in message
news:b6ds7v0dgdsddvogn...@4ax.com...
> Maybe that's not even strong enough? I
> figure just under two cubic feet in total volume. Can fiberglass
> handle that?
>
Have you ran across those folks over at the cast stone institute
www.caststone.org? They are mighty particular as what is called 'cast
stone' - they seem to prefer quite a dry mix, tamped not poured. The trouble
with formulas, as you probably know is that they often change day by day,
according to the job at hand, and the unique local nature of your materials
(for example something like 'sand' can have tremendous variations to the mix
design and texture). I might be willing to share some rough formulas, but
first:
two cubic feet would weigh 200lbs if cast as solid. To get the weight down I
would suggest you use glass fiber reinforced concrete ( appr 15 lbs a sq
foot, at 1/2 to 3/4 inch thick) - but this will have to be hand laid up in
the mold, usually with a face mix first - you might not have room to work.
Are you thinking of a solid 'piece' mold for casting - in which case layers
of fiberglass and resin are the best choice. A rubber mold (usually
urethane) is commonly supported with a fiberglass mother mold. With the
weights involved, many people would also build a frame for the mother mold,
and the frame would help to move and mount on a vibration table as well.
Casting two hundred lbs by yourself might be difficult without some pullies,
mechanical devices - cheaper than hiring a helper, since the animal rights
activists have banned the use of slave gorillas, working for bananas,
If you are just getting into this field, I strongly advise you take a
beginners welding course, buy a cheap mig welder and gas torch (and safety
gear). You will find 100 uses for these skills making up jigs, armatures,
reinforcements, custom bits of equipment. A pan type mortar mixer would also
be a godsend - you will get real tired of hand mixing with a 3/4 inch drill.
and a 'cement mixer' makes too wet slump for quality work (ie artistic or
architectural grade cast stone).
Welcome to alt.sculpture! You can attach jpegs too - just keep them under
50k and maybe a separate post because not all world wide servers will pickup
photos in a non-binary newsgroup.
Raymond
wrote:
Yes. I've been there. I went through their specifications. Didn't
find anywhere to tell me how to do it, just what it should look like
when I'm done.
I also found a basic formula for stepping stones which I thought I
might experiment with if I don't get a better offer.
http://www.elvesofester.com/formula.html
I also found the following quote from a 1999 discussion in a Deja News
search (it is from alt.sculpture).
"I prefer a richer mix for casting cement, two parts aggregate to one
part cement (by volume). All of my cement casting is done 1/2, white
portland cement/#1 marble chips. Or 1/1/1, white cement/chips/white
sand. Use as little water as possible. (These formulas yield a product
that gets so hard a cat can't scratch it). I weigh my ingredients, and
the water I use is about 40 per cent of the weight of the cement.
Roughly. Experiment, and keep notes of your results. Less water equals
more strength."
>Are you thinking of a solid 'piece' mold for casting - in which case layers
>of fiberglass and resin are the best choice.
This is preferred but I can go any direction. Two halves split down
the middle would look tacky as I don't know a good way to hide the
seam. There has to be a bronze pipe sticking in the Manatee's butt
which serves both as a support and as a conduit to supply water via
1/4 inch copper line which runs to his mouth. I designed my clay
model so that the center of gravity is right through his middle so
that if he is poured around a bronze pipe (I think 1 1/2 inch
diameter), he won't be off-balance.
He will have to have a rebar and wire frame because he has a flat tail
about 8X12 inches and two legs that protrude about 8 inches. I am
having difficulty envisioning tamping the mixture into a mold with
such a framework. Pouring and vibrating I can do, but I have never
made a piece that required tamping.
>A rubber mold (usually urethane) is commonly supported with a fiberglass
> mother mold.
This is what I am finding in my research into ornamental concrete.
>With the weights involved, many people would also build a frame for
>the mother mold, and the frame would help to move and mount on a
>vibration table as well.
I have a vibration table, although I will have to make it larger for
this project. I have a table to which is mounted an electric motor.
Attached to the motor shaft is a 6 inch pully. I ground off part of
one side of the pully so that it is out of balance. Turn it on and it
will walk the table to Fresno. I burned out one motor, but I have an
endless supply from a friend who scraps out old washing machines. I
don't care to get any more sophisticated than that for now as long as
it works. If I get good at this, I might invest in a vibration wand.
>Casting two hundred lbs by yourself
Thank you for this weight calculation. I have not yet learned how to
do this.
>Animal rights activists have banned the use of slave gorillas, working for bananas,
Dammit.
>
> buy a cheap mig welder and gas torch
My father was a welder by trade, and taught me how. I am a decent
welder. I have a torch but not a mig. I do mostly brazing. Mostly
rebar. I am prepared to tackle a frame to support the mold.
>
>Welcome to alt.sculpture! You can attach jpegs too - just keep them under
>50k and maybe a separate post because not all world wide servers will pickup
>photos in a non-binary newsgroup.
>
Thank you for the response.
Battersby
> I also found a basic formula for stepping stones which I thought I
> might experiment with if I don't get a better offer.
> http://www.elvesofester.com/formula.html
> I also found the following quote from a 1999 discussion
> "I prefer a richer mix for casting cement, two parts aggregate to one
> part cement (by volume). All of my cement casting is done 1/2, white
> portland cement/#1 marble chips. Or 1/1/1, white cement/chips/white
> sand. Use as little water as possible.(These formulas yield a product
> that gets so hard a cat can't scratch it). I weigh my ingredients, and
> the water I use is about 40 per cent of the weight of the cement.
> Roughly. Experiment, and keep notes of your results. Less water equals
> more strength."
That's a quote from one of my postings. The formulas are the same as the one
at the elvesofester webpage, less the optional additives.
For the aggregate, substitute pea gravel, granite, quartz or limestone, if
desired. Use white portland for some colors, natural gray portland for
others, if pigmenting. Sand color is also a factor when pigmenting,
particularly with white portland.
I read through Sonafrank's info the elvesofester webpages, and that is all
good information.
> He will have to have a rebar and wire frame because he has a flat tail
> about 8X12 inches and two legs that protrude about 8 inches. I am
> having difficulty envisioning tamping the mixture into a mold with
> such a framework. Pouring and vibrating I can do, but I have never
> made a piece that required tamping.
You will not be able to use a dry tamp formula for this application. The
formulas above are for a poured technique. You have not picked the simplest
project to begin your learning curve. I would recommend producing a
drastically scaled down version first to get your feet wet. Experiment on a
small manatee and keep very specific notes.
> I would like to pour the manatee in cast stone.
Cast stone can be poured or dry tamped.
> I can build the mold
I would say silicone or polyurethane.
> If this one works according to my vision,
Be sure to post back with results, or any further questions.
--
Battersby.
T. M. Battersby, stuccoist.
http://www.battersbyornamental.com
tbatt...@satx.rr.com
Raymond wrote
I have finished my clay, a manatee about 40 inches long. Now I want
to construct a garden fountain and incorporate my manatee (spitting
water into the pool). The fountain pool is not a problem as I have
made hundreds. The Manatee is the problem. I would like to pour the
manatee in cast stone. I can build the mold, although since I won't
be pouring wax I will have to re-think materials. I have made a
couple of small bronzes and took them to the point of making and
chasing my own wax. (I learned sculpture at Loveland). Those clays
were small, around 12 inches, so the molds were simple plaster. Maybe
I need fiberglass here? Maybe that's not even strong enough? I
figure just under two cubic feet in total volume. Can fiberglass
handle that?
Then comes the hard part. I have never worked in cast stone, although
I do simple non-mold-related concrete fountains with waterfalls, etc.
Is there a formula for cast stone? Is there a commercial mix I should
use and forget mixing my own? Are there any books you can recommend
about this specific subject? I have scoured the net and there is a
lot about restoring architectural cast stone, which I am studying, but
it is mostly about technique only, and mostly about matching existing
stuff. I have yet to find any formulas.
Any comments about any of this are greatly appreciated. If this one
works according to my vision, I can get away from running water over
stacked stones and start doing something more satisfying.
> On Mon, 24 Mar 2003 04:20:48 GMT, "Gary Waller" <ga...@mozaya.com>
> wrote:
> >Have you ran across those folks over at the cast stone institute
> >www.caststone.org?
Raymond wrote
Gary Waller
If you are going to learn by following a tightly specified formula, be
careful on the sand, which is often sold wet, and the moisture can vary from
the top of the pile to the bottom. Make sure you know the weight/volume of
the dry sand, so you can figure out exactly how much water is in it.
With that book link, and here is another website
www.taconic.net/kanwit/park.htm
You might consider sculpting manatees in the one at a time, with the each
piece hand modelled, method. This way you can scale the size and gestures
specific to the location, and a satisfactory end result is more likely (and
more $$$work from it). The trouble with cast is that you have no control
where the customer puts it. Make your armatures, mix up layers of concrete,
and model the piece in setting concrete - acid stain and polish it out if
you want. Customers are able to afford a beautiful piece of art - without
the material costs of stone or bronze. I also think there is also great
opportunity to make 'sculpted rock' sculptures - like Grizzly Mountain at
Disney's - it looks like a rock/landscape feature and then you notice a
figurative shape. There is a course coming up in Colorado, which is the
closest you will get to insiders training on this technique and sculpting in
concrete:
<<-Ted Baumgart and Frank Manwarren, August 14th-18th.
Ted has a great deal of experience in the manufacture and especially in the
finish of Faux rocks and rock features. Ted learned his craft from one of
the originators and major players in the field, Frank Manwarren. The course
participants will be learning and doing by making Faux rocks and
constructing a Faux rock pond and waterfall.
If you are interested in any of the courses please email me privately
h...@montrose.net
best regards,
Paul>>>
Frank Manwarren is in his 80's - might be one the last chances to learn from
a master, I think its around $550. Might see you (or other from this
newsgroup) there!
There is another master Johnny Johnstone, but he sticks to training union
apprentice masons, based out of Las Vegas I believe.
Pete Goodridge
says plaster, plaster, plaster. If I were sculpting Bacchus, Mr.
Kanwit would be my model.
Here is another website www.taconic.net/kanwit/park.htm
Gary Waller
like I said on another group -- for every sweaty person mixing stonemud,
there are twenty people looking over their shoulder giving advice, opinions,
definitions, urban legends and tall tales.
It is probably cement plaster - here is the last website giveaway - I
noticed they call it cement plaster on this site.
http://www.rockandwater.com/ArtificialRockWaterfallsBook.htm
I'm still not giving away my formulas for screeded and running mold
concrete, which is OK, since 99.9% of this trade have never heard of a horse
riding on a gigstick anyway (not you Battersby!). I still like architectural
and archeological themes. Have done just enough movie work to twist my
tastes I guess. Who wouldn't want the Laura Pond - Tomb Raiders Set, up
around their backyard swimming pool. Or for Pete - a Dionysus Diorama, (with
the optional vestial virgin party pak) (ps I noticed that Kanwit wanted to
'sculpt the Three Graces as pregnant, but gave up after two' now WAssup
wid dat??)
"Pete Goodridge" <lily...@hotmail.com> wrote in message
news:f2b9123f.03032...@posting.google.com...
Simon
I very much doubt it would involve plaster for any outside rock, or inside
rock, where it's in contact with water, like a waterfall, as plaster, no
matter how well it is sealed is basically hydroscopic ....... there's only 2
varieties of cast rock that i have ever seen and used ..... either a
polyester/GRP cast ..... or a fibreglass/cement cast ...... the latter
having additives to increase certain properties, plasticisers,
waterproofers, etc. ... mixes and formulas are going to vary from place to
place and people to people with many people arguing for different formulas
... casting isn't a necessary option ... i have built a few waterfalls .....
using the concrete mix straight on to a former ... with a good artistic eye
and technique it is a lot quicker than going to the trouble of finding the
rocks you like and making silicone moulds of them ....... a steel or wooden
frame, fine mesh chicken wire (galvanised wire mesh if you don't call it
chicken wire over the pond) .. shape it out in what ever shape you want ...
and start laying fibreglass and cement over the former ..... the other
option is to sculpt the shape out of polystyrene blocks and lay the
concrete/fibreglass over that .. (Note; you can't use polyester with out a
considerable barrier as the solvents will turn the polystyrene to mush) .. I
made a waterfall using the wiremesh former technique and a ready mixed
product called "Pointing repair mortar", that you can buy here, with a
waterproofer/plasticiser . the mortar already has the fibreglass mixed in ..
the waterfall is going fine with no sign of deterioration and it's been up
for 8 years.
all the best
Simon