# Sand casting



## Deadna (Oct 19, 2002)

That looks great! I DO need a clean casting so how do I grind the kitty litter without ruining my only blender? Also....once you get the green mix wet and make a mold does the kitty litter in it harden(clump) and keep the shape you created or can it be reused for a different mold?


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## partsman (Oct 18, 2007)

Well you could make a tumbler out of a five gallon bucket, a motor and some rollers and put some stones in with the cat litter, that should work, would just take a bit longer. Also, no it doesn't harden unless you let it get really dry, I keep mine in a plastic bag and reuse it over and over again, you just need to keep it moist. If you need to make a really smooth casting, just change your ratio of sand to cat litter, the more bentonite you have in the mix, the smoother the end result. Also the finer you can sift the sand the better your end casting will be. I was looking for a rough stone look, so I didn't sift the sand really fine, if you want a smooth finish I would suggest doubling up your screen for a finer mix.


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## riverswampboat (Sep 20, 2010)

Not sure if this will help or not, but if you need a smooth bentonite ( I assume cat litter is coarse) find a well drilling supply company or a water well driller and ask for drilling mud.......bentonite (which is a clay) comes in 50 pound bags and has the consistancy of flour. It is used in well drilling fluid to make a smooth wall on the bore hole so it dosen't cave and to help move cuttings from the hole. It is relatively cheap.....(around 7 dollars for a 50 pound bag.
I never thought of using bentonite and sand for casting.......Thats a GREAT idea Thanks for posting the idea!


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## Terra (Sep 23, 2007)

Incredibly easy and looks perfect for tombstone details. Thanks so much for this!


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## partsman (Oct 18, 2007)

riverswampboat said:


> Not sure if this will help or not, but if you need a smooth bentonite ( I assume cat litter is coarse) find a well drilling supply company or a water well driller and ask for drilling mud.......bentonite (which is a clay) comes in 50 pound bags and has the consistancy of flour. It is used in well drilling fluid to make a smooth wall on the bore hole so it dosen't cave and to help move cuttings from the hole. It is relatively cheap.....(around 7 dollars for a 50 pound bag.
> I never thought of using bentonite and sand for casting.......Thats a GREAT idea Thanks for posting the idea!


I didn't know anything about well drilling, so didn't know about getting bentonite that way, yes cat litter is course, but relatively easy to make fine, just be sure to use a mask so you don't breathe the dust as it is very bad for you (black-lung). Believe it or not, but I almost didn't post this, as I mostly lurk now and don't do much in the way of posting anymore. I really wasn't sure anyone would be interested in this at all.

Oh you're welcome Terra, I should mention that if anyone is going to make a two part sand mold, you should sprinkle the first half of the mold with talc before putting more sand in to make the second half, that way you can separate the mold cleanly.


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## madmax (Dec 28, 2003)

I been doing this for years but I only use sand with water, just enough to dampen the sand so it holds together when you press the object you are casting into the sand.

The major problem when casting with greatstuff is shrinkage and I had mixed results with that...sometimes it does and other times it doesn't.

You won't get perfect casting but it's a easy way to get castings for pennies when you don't need perfect. Here's a few that I did using sand...

I used a foam head, a plaster skull and a biglot skeleton to make these sand cast then 










used my own hand for these










used another foam head and my own hands and forearms for these....before the foam is fully cured (but not sticky) you can form it by pressing on it to get smaller arms










add a little caulk and spray paint to get that skinned zombie look...total of 15 minutes of work time from casting to finish and maybe $3 dollars/one can









here's another sand cast head with the foam head I used as a model


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## chinclub (Oct 6, 2011)

So how do you get both sides, like this the hands and arms? Is there still a flat edge you can't see in the pictures?


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## Xane (Oct 13, 2010)

Raid thrift stores and look for a cheap mini-food processor or coffee grinder. It'll take longer, so depending on the amount you need you may as well buy a cheap blender or food processor instead. I recommend you gently "pulse" things until they're small, then full power chop the rest of the way. It was a freak accident, but back when I was active in the polymer clay newsgroups, someone using a food processor to condition (knead) the clay had a blade snap and fly right through the (plastic) tub into the wall.

Edit: the main issue is do not do anything that could cause the blade to "jam" while spinning. A cheap food processor is actually more likely to simply burn out the motor or strip the gears, an expensive one will power right through it until the blade breaks.

http://groups.google.com/group/rec.crafts.polymer-clay/msg/1e1fb39e6a31adac?hl=en


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## partsman (Oct 18, 2007)

chinclub said:


> So how do you get both sides, like this the hands and arms? Is there still a flat edge you can't see in the pictures?


Here's a video that shows the green sand method for making a two part mold, that's the sand with the clay in it.

http://www.youtube.com/watch?v=SVUSJuYQhA4


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## chinclub (Oct 6, 2011)

Thanks, I will check that out now.


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## Kymmm (Oct 1, 2009)

I watched that video and I'm still not sure how you made your hands. Could you explain how you did it? I would appreciate it!


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## partsman (Oct 18, 2007)

Kymmm, I didn't make those hands, madmax did those, I merely posted the video to illustrate how it could be done.


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## Kymmm (Oct 1, 2009)

Oooops... sorry, got my posters mixed up.


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## ssflipo13 (Nov 8, 2008)

OMG! do you see what you just did!? You got me hooked! I want to do this so bad now I can make all the skulls i need! YES! ty for sharing this with us. LOL MY wife is going to kill me! hahahaha


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## partsman (Oct 18, 2007)

ssflipo13 said:


> OMG! do you see what you just did!? You got me hooked! I want to do this so bad now I can make all the skulls i need! YES! ty for sharing this with us. LOL MY wife is going to kill me! hahahaha


Lol, you're welcome! Glad you like it, I'm happy to help.


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## CShuler (Jan 26, 2012)

I agree, I have a ton of skulls to make, and this is exactly how I'm going to do it. Thanks for sharing!


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## Txjoker75 (Jan 12, 2012)

Works great have made several skulls using this technique, thanks for shareing


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## partsman (Oct 18, 2007)

I'm happy you all enjoy this, I'm up to 45 skulls so far, I think I'll need about another 50 or so to do what I have planned.


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## Paint It Black (Sep 15, 2011)

How long does it take for the great stuff head to cure enough to take it out of the mold?


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## partsman (Oct 18, 2007)

Paint It Black said:


> How long does it take for the great stuff head to cure enough to take it out of the mold?


I'm not really sure, I usually mold up between 8-10 skulls at a time and just leave them overnight, they've always been ready to come out the next day when I go down and pull them out.


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## znelson710 (Apr 20, 2009)

If I wanted to keep the stone texture for adding appliques to tombstones will the sand stick to the piece or does it brush off?


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## madmax (Dec 28, 2003)

znelson710 said:


> If I wanted to keep the stone texture for adding appliques to tombstones will the sand stick to the piece or does it brush off?



Here's some sand casting I did years ago 




























Can't really see it here but it was still textured after painting 









This $3,000 prop was what I was trying to make....for under $50 dollars. 









This is what I ended up with 











________________________________________________________

Paint It Black it depends on how deep your mold is..

Sand casting comes out in 10 to 20 minutes in hot dry conditions....dampness takes longer and stops the foam from reaching it's full expansion

This took a day then on my next cast I did it in layers and it only took 90 minutes










Plastic hands only took 10 -15 minutes


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## doto (Nov 20, 2009)

Max I think the mechanism behind your lunging reaper might also deserve a tutorial. Partsman Thanks for the Tut.


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## DoctorGrim (Oct 18, 2007)

Madmax,

That is such an amazing way to create body parts. I'm always burning time to make hands & feet. This method kicks a**.

I really HAVE to try this. Thank you so much

Still confused on the 2 part mold though.

Partsman, the scull molds look fantastic.


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## Danielj2705 (Jun 17, 2012)

This is Brilliant, I think I am going to make Bones as I can't seem to find any cheap ones in Britain :/ 

Also madmax that is amazing, I bet your glad you didn't buy the $3000 one


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## LT Scare (May 21, 2008)

This is such a great idea! I've made about 35 skulls of varying sizes so far. Mine are painted black, with many wired for red LED eyes. They will be attached to the outside of corner pillars for the cemetery fence. One pillar will house a projector for the Disney singing busts. 

My castings are pretty rough, but that's fine for my application. Also, mine are distorting as they dry - again, fine for my application. I think my sand is too wet. I bought the finest sand I could find and I'm not using the kitty litter. FWIW


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## BadTableManor (Sep 8, 2007)

I'm so glad you posted this! I've been making sand castings out of hot glue, but I like this idea much better. Thanks for sharing!


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## bkr1969 (Nov 29, 2009)

Powdered bentonite clay is very common in hobbyist fireworks (a previous endeavor of mine). It is cheap and easy to obtain. Two of the biggest suppliers are www.firefox.com (in Idaho) and www.skylighter.com (Virginia).


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## madmax (Dec 28, 2003)

doto said:


> Max I think the mechanism behind your lunging reaper might also deserve a tutorial. Partsman Thanks for the Tut.



You want believe me when I tell you that mechanism took a whole 30 minutes to put together or what it is. Well you will as soon as I point out what it actually is. Instead of building linkage from scratch and drilling holes or welding...I go to the thrift store and play around with any exercise equipment they have. I watch how the joints move and see where things are bolted together and decide, hey I can make that into a prop. With very little work and usually under $8 dollars.

Now that I told you that look at this picture and think of this devise setting on the ground with both ends down best I can remember it was a weight bench of some type but it's been 6 or 7 years


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## partsman (Oct 18, 2007)

I leave them for about 2-3 hours, the moisture in the sand moves the cure alone pretty quick.


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## moonwitchkitty (Jul 22, 2012)

ZOMG!!!!! can't wait to try it out. Thank you


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## gcbean (Oct 4, 2011)

Awesome. I almost spent big $$$ on skulls today for a minor application. Thanks! I might be hitting you up for minor details next week.


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## Lazy D (May 14, 2011)

ehh i seam to be messing up some where, i just can not get the sand to come out right. when i pull the skull back up it pulls up the sand also not leaving detail behind


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## LT Scare (May 21, 2008)

OK, I've made about 250 half / three quarter skulls using a variation of the method that started this thread. Right up front I'll tell you that I've been after quantity more thant quality. My skulls are painted black and I've installed LED eyes in most of them. They cover the outside of two cemetary pilars. My experiance is that little detail can be seen at night, even with accent spot lighting. I used only a medium/fine sand and Great Stuff foam for the first 230 or so. Because I'm mounting the skulls on a flat surface, I sliced the back of the skull (the expanded Great Stuff) off at various angles so that the LED eyes "look" out at variouse angles. 

I found that I got various results due to the following:

Always wear throw away gloves to work with the foam.
Removing the skulls from the sand too soon and triming the excess foam will "deform" the sculls and shrink them. The result is commendably creepy looking but covers less area.
Keeping the sand very moist and leaving the skulls in the damp sand at least over night resulted in the least distortion and shrinkage.
One can of GS (just under $4 at Home Depot) will yield about 10 -12 regular sized skulls.
The resulting skull can be spray painted without being "eaten up." I used the $.97/can of flat black spray paint from Home Depot on most. I am now using some light beige spray paint on some skulls for my "Wall of Skulls" entrance. Again, no problem with the foam.
Swtiching from the Great Stuff to a red label "GE" foam I found at Walmart ($2.97) resulted in almost zero shrinkage or distortion, quicker drying time, and a much lighter skull. This General Electric foam drys very much like a rigid sheet of styrofoam - not coffee cup styrofoam, more like the stiff rigid foam florists use to stick plastic flower stems into for an arrangement.
I found this GE foam spray just in time to turn out bunches of skulls for the entrance that I don't want distorted much.

Hope this helps someone. IF you like, I can post pics of the distorted skuls and the new skulls (minimal distortion).


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## Old Man Bakke (Oct 18, 2011)

Oh shrinkage my enenmy!!

Any suggestions?

Anybody?

I have been doing both sand casting and blow form casting.

very discouraging, please help


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## moonwitchkitty (Jul 22, 2012)

what are you using?


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## Old Man Bakke (Oct 18, 2011)

Great Stuff


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## moonwitchkitty (Jul 22, 2012)

According to how to haunt your house you can use hot glue will not shrink.
will get back to you tomorrow i have a book that will give good advice. unless you already have it. The props Builder's Molding & Casting hand book


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## Old Man Bakke (Oct 18, 2011)

Oh please do Kitty!

I am very curious!

Hey, thanks for your time and input too! I really appreciate it!


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## moonwitchkitty (Jul 22, 2012)

Ok it didn't take so long says you could use plaster but it takes 3 to 4 days to cure.
hot Glue takes 10-30minutes to cool
Hot- Melt rubber until cools
Water- Extendable Polyester or WEP Takes 20minutes 
Water Putty 30minutes


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## Old Man Bakke (Oct 18, 2011)

That was a bit cryptic.....but i will look into that book 

thanks!


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## Onewish1 (Dec 2, 2010)

thanks for posting this on haunters list today.. totally going to try this!!!!


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## McBernes (Mar 10, 2015)

Cheap and easy...I like it!


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## LT Scare (May 21, 2008)

Old Man Bakke said:


> Oh shrinkage my enenmy!!
> 
> Any suggestions?
> 
> ...


For my application, the shrinkage is not a big deal - makes them creepier IMO. 

If I was making a batch today, trying to minimize shrinkage, I would make sure the sand was very wet and stayed wet during the drying process. 

I would also try to use less Great Stuff - just enough to cover the sand. In the past, I would use enough GS to assure there would be most or all of the back of the skull too - even if I trimmed it with a knife. The GS will dry from the outside to the center - center last to dry. As the inner GS drys, it pulls the outer GS in. Try to shoot the thinnest coat possible onto the sand and there should be a more uniform drying of the GS and (??) maybe (??) less shrinkage (??). 

I'm not sure, but logically, it would seem that a colder, more damp environment would slow the drying and would reduce shrinkage too. I made all of mine in the Garage in So Cal in August = shrinkage.

FWIW


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## UnOrthodOx (Apr 24, 2007)

LT Scare said:


> For my application, the shrinkage is not a big deal - makes them creepier IMO.
> 
> If I was making a batch today, trying to minimize shrinkage, I would make sure the sand was very wet and stayed wet during the drying process.
> 
> ...


I've had decent luck using a spray bottle to dampen the back side of the great stuff after I spray it in. I also agree with the thin coat around the outside and hollow center method over large blob that fills an area.



> Ok it didn't take so long says you could use plaster but it takes 3 to 4 days to cure.


Plaster might take 3 - 4 days to FULLY cure, but you can typically handle it within 30 minutes to an hour.


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## spookeecat (Apr 1, 2015)

Thanks so much for this post. This is exactly what I was talking about today for a non-Halloween project! But now I am excited to try it for both the planter I am trying to make and to make some items for Halloween


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## partsman (Oct 18, 2007)

Hey everyone, I just went back and fixed the photos at the beginning of this thread to make it useful again. I wish Photobucket hadn't fallen apart, I've been reposting literally thousands of photos all of the inter web


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