Making Miniatures

Gettin' the lead and makin' it pretty
thedugan
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Postby thedugan » Tue Oct 28, 2008 12:14 am

jimbeau wrote:it's a plaster-type powder about $1 per pound all-in all including shipping


Yeah, I looked at the Excalibur, it's got more strength, and it's a bit cheaper. I've worked with Plaster before. Remember the "Tank" I sent you?
:D


jimbeau wrote:for me, I have about 40 pounds left, so I'm going to use it whether it's cost-effective or not.


Sure...why not try to make a ship or something with it, and/or something that has a thin cross-section? It'll give you an idea of the stuff's limits. I have to figure out how to use Pay Pal and find my password...


jimbeau wrote:I'm slightly surprised the mold worked too. But work, it did.


Yeah, I need to come up with some models to cast. I've been in cleanup mode for a month now, I've got a stack of Godzilla movies. :shock:
Becuz I'm da friggin' ART FAIRY - dats why!

Big Bang = Let there be LIGHT!

thedugan
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Postby thedugan » Tue Oct 28, 2008 12:31 am

nathan wrote:It's a totally different material to resin. I'd recommend gettting a smaller amount if you're not familiar with it or know that you want to cast something definitely with plaster/die stone.


Likely, I'll work up a few models first. That's going to take a while. I've worked with cements and plasters before....


nathan wrote:I'm heading the opposite direction. I've worked with die stones and dental plasters and am just getting started with resins (started with cheap polyester resin from an autobody supply shop).


Did you do the Hirst Arts thing? Most of the links that folks been putting up are familiar, I've been there before.


nathan wrote:The last 50 pound box of die stone I bought was like a foot wide cube. The die stone was bagged inside of that and filled the box up about 90% of the way.


THAT is the information that I needed. A "foot wide cube" is like 7.48 gallons IIRC....that's a BUTTLOAD of resin, and answers my cost question. Unless the diestones are totally unsuitable for the model in question, I'm thinking that they are much cheaper for the given volume, given what you and Jim have said.

I've also read up on casting pot metals and aluminum, but that's likely going to be overkill. :)

nathan wrote:Die stone feeds and feeds into water. You'll be surprised at how much a given volume of water will absorb.


As long as it's not more than 4X the water volume, you're still ahead.

nathan wrote:My general thinking is that plaster/die stone is better for some terrain and resin for miniatures. Whether or not I'd go with resin or die stone would be a decision made on a case by case basis depending on the shape of the piece and the nature of the mould.


Pretty much - unless the thing is really delicate, diestone comes out ahead in my thinking.

nathan wrote:Also, never dispose of plaster/water solutions down the drain. Always let the plaster set completely and throw it out. Sounds like a no brainer, but it's easy enough to forget and it only takes one time to block a pipe. And even a really thin plaster/water solution will cause a build up over time.


Everyone keeps telling me that. :)

I dump it in a trash can...might be able to recycle some chunks. Yeah, I'm THAT cheap...
:)

nathan wrote:
thedugan wrote:I'm not questioning that it worked, just whether or not it's the most cost-effective solution.


My thinking is that for a meteor, the rotating with polyester resin to make a mostly hollow cast might be the way to go. Like the guy did with the rock casting on the taxidermy site.


I'd just cast the whole thing in plaster. Time is money...or, you could slush cast the exterior in a diestone, and fill with plaster. Can you slush cast with a diestone?


nathan wrote:Die stone is about strength rather than volume, so it takes a surprisingly high weight of dry powder to make a given volume of plaster. So as far as cost effectiveness goes, if you can mix up polyester resin in small quantities and get good results with it, that'll probably be cheaper than die stone. Die stone has the advantage of being all water based with no nasty fumes though. And it's more sandable/workable than polyester resin. Also, less heat is produced, so you can get a longer mould life.


Yeah, the fumes and ease on the molds is a biggie....
Becuz I'm da friggin' ART FAIRY - dats why!

Big Bang = Let there be LIGHT!

jygro
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Postby jygro » Tue Oct 28, 2008 2:55 am

The detail on the rock is awesome. I'm definitely going to have to try that casting method!

-Bren

go0gleplex
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Postby go0gleplex » Tue Oct 28, 2008 3:38 am

another reason not to dispose of this stuff down the pipes is that it's illegal. Not that big brother is gonna come knockin at your door for it...but if they do...ouch.

thedugan
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Postby thedugan » Tue Oct 28, 2008 3:36 pm

I'm thinking that plaster isn't that toxic. It's ROCK........albeit chemically or thermally altered, but nothing in it is going to alter anything in a stream's biochemistry.

If we were talking polyester esters, then yeah...
Becuz I'm da friggin' ART FAIRY - dats why!

Big Bang = Let there be LIGHT!

go0gleplex
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Postby go0gleplex » Tue Oct 28, 2008 5:31 pm

thedugan wrote:I'm thinking that plaster isn't that toxic. It's ROCK........albeit chemically or thermally altered, but nothing in it is going to alter anything in a stream's biochemistry.

If we were talking polyester esters, then yeah...


It's still illegal...classified by the EPA as a Non-point source pollutant and in most jurisdictions a major do not dump item. And even concrete alters the pH balance of water. ;) This IS what I do for a living after all...;)

thedugan
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Postby thedugan » Tue Oct 28, 2008 6:05 pm

go0gleplex wrote:
thedugan wrote:I'm thinking that plaster isn't that toxic. It's ROCK........albeit chemically or thermally altered, but nothing in it is going to alter anything in a stream's biochemistry.

If we were talking polyester esters, then yeah...


It's still illegal...classified by the EPA as a Non-point source pollutant and in most jurisdictions a major do not dump item. And even concrete alters the pH balance of water. ;) This IS what I do for a living after all...;)


..and that's what's WRONG with America.

Rock is a pollutant? Blow air through water and it will shift the pH. ANYTHING will shift the pH of water. Even pure water will shift the pH of water. Water Chemistry is ONE of the things I do.

It's like the EPA proposing reducing the silica content of the air in west Texas when the wind is high. Some nitwit actually proposed putting Lubbock down on the list as a non-attainment area for the excessive silica in the air.

....soooo, we're going to filter out the sand from the air?

The Philipines is looking more attractive by the day. At least I can afford to pay off the politicians there.
Becuz I'm da friggin' ART FAIRY - dats why!

Big Bang = Let there be LIGHT!

thedugan
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Postby thedugan » Tue Oct 28, 2008 6:10 pm

..oh, and I did say "BIO" chemistry.

I assume the EPA is more concerned with protecting endangered species of pond slime that the actual water chemistry.

Of course, that's an ASS U M PTION...
:roll:

Fine, I'll dump it in the trash, right next to my oil fliters....
:lol:
Becuz I'm da friggin' ART FAIRY - dats why!

Big Bang = Let there be LIGHT!

nathan
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Postby nathan » Tue Oct 28, 2008 6:37 pm

thedugan wrote:THAT is the information that I needed. A "foot wide cube" is like 7.48 gallons IIRC....that's a BUTTLOAD of resin, and answers my cost question. Unless the diestones are totally unsuitable for the model in question, I'm thinking that they are much cheaper for the given volume, given what you and Jim have said.


I just want to say that I wasn't being in any way accurate with that foot cube comment. For all I remember, it could have been 9 or 10 inches (though I think it was bigger). That makes quite a big difference once you're working out volume. I'd ask for the dimensions/volume and mix ratios from any seller. Find out exactly how much you're getting in true casting volume.

One of the problems with filling a slush/roto-cast resin piece with plaster is that plaster expands. While not lots, you could get a crack in the resin shell from the pressure. I know time is of the essence for many hobby pursuits, but I'd probably pour the inside of the resin shell in two stages, letting the plaster cure at least part way between the two. My current thinking is to simply fill them with an expanding polyurethane foam or a plaster/die stone with lots of filler to keep the weight down.

And yes, you can slush/roto-cast with die stone and plasters. It just takes a bit of patience. Die stone that sets rapidly is obviously better than plasters that usually take longer. I don't think it would work very well by hand. You'd probably need to build some crazy roto-casting contraption. Or be willing to sit there watching TV rotating a small mould by hand for half an hour. If you get a die stone that is made for quick setting, you could probably get that down to 10 minutes.

Did you do the Hirst Arts thing? Most of the links that folks been putting up are familiar, I've been there before.


Yeah, I did some hirst arts blocks. Took an awful lot of work/time unless you had multiple moulds or made moulds of blocks you wanted in higher quantities. I always thought the Linka approach was better, where you cast wall pieces rather than individual blocks. But that's the wrong scale for me, so I'll have to make my own wall moulds for 10mm/N-Scale buildings.

thedugan
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Postby thedugan » Fri Oct 31, 2008 6:05 pm

FYI...

http://www.canyonstatedentalsupply.com/garreco2.htm

Don't know whether they sell to non-dentists or not, I just ordered a 50# box from Clint Sales, and was looking for something else.

Don't know about shipping, either...
Becuz I'm da friggin' ART FAIRY - dats why!

Big Bang = Let there be LIGHT!


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