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i made my fish. i casted it and its base in plaster to form a mold. i will make a rubber mold of this mold to make multiple plaster Si kiln molds. anyhow does anybody know if the downey softener will work as a seperator between my plaster mold and the brushable 2 part rubber i am going to use on it? i do not want to permanently seal the plaster piece as i can then use it as a mold for porcelain clay. rosanna

rosanna gusler wrote:i made my fish. i casted it and its base in plaster to form a mold. i will make a rubber mold of this mold to make multiple plaster Si kiln molds. anyhow does anybody know if the downey softener will work as a seperator between my plaster mold and the brushable 2 part rubber i am going to use on it? i do not want to permanently seal the plaster piece as i can then use it as a mold for porcelain clay. rosanna

I know nothing about using fabric softener as a release. A can of spray silicone works well. Murphy's oil soap probably works. Vaseline works. Pam might work. Becuase the paint on rubber is flexible and the plaster is not, you have a pretty good shot at getting it apart.

You do need to make a plaster mother. Once your rubber has setup, make a plaster around it to keep in in the correct shape. You can put some plastic sheet or something between the plasters to keep them apart after the mother has set. Do put some more release over the rubber before making the mother.

thanks. i called smooth on and they only reccomend their tm products. not that i blame them, i just do not want to invest alot of $ in something i am not sure will work. dani? reccomended the downey to me and it has worked fine with that one part craft store mold maker. anyhow i baked the mold in the oven over night to dry it and will start the rest of the process today. where did you find spray silicone? rosanna

rosanna gusler wrote: where did you find spray silicone? rosanna

Hardware or auto parts store

rosanna gusler wrote:i made my fish. i casted it and its base in plaster to form a mold. i will make a rubber mold of this mold to make multiple plaster Si kiln molds. anyhow does anybody know if the downey softener will work as a seperator between my plaster mold and the brushable 2 part rubber i am going to use on it? i do not want to permanently seal the plaster piece as i can then use it as a mold for porcelain clay. rosanna

Downy is what we use.... after one round with Vaseline! Oh, dear, that was a mess. That's what our local foundry recommends.

Rosana...check out this website for a great table for what kind of release agent works with various mold and casting mediums.

http://www.artstuf.com/releaseagent.html

I use this table all the time. It's from Douglass and Sturges' website. They specialize in all kinds of mold making materials for sculptors and are located in San Fran.

Their website is http://www.artstuf.com.

wow! thank you carol. great info. i went in to napa this am and bought a can of spray silicone and used that. i just put the last coat of rubber on the mold. they suggest a post cure so i will bake it tomorrow. (when my dh is not home) then we will see if i have a mold mold. i hope so. i have this idea of a fish series. lets hope mr striper works out. rosanna

rosanna gusler wrote: i have this idea of a fish series. lets hope mr striper works out. rosanna

Better hurry up that fish is going to start to stink.

ha ha . plasticine does not rot. i do hope this works though because i also want to do a 'fillet and release' series. carnivorgirl

wow what a learning curve with this stuff! i sprayed my thoroughly oven dried mold with alot of silicon and did layers of rubber. cured that and made a mother of the back. took off the mother and tried to pull the mold mold off the origonal. it would not come off. i yanked, cursed, smashed the plaster, stomped on it and was on the way to the garbage when i passed a bucket of rain water.........dumped it in there and my plaster started to melt. much scrub brush work later my mold was clean. i guess the combination of old plaster and mold abuse in the oven was a good thing. anyhow, i pulled my first plaster silica kiln mold out this am. i really like this stuff. i just have to figure out how to properly seal and 'grease' my plaster origonals before using the rubber. rosanna

SPeaking of release and filet.

A couple of hints. Be careful how greasy you get your live/dead fish. If you are looking for detail, even a thinnish layer of Pam can cover some of the detail.

Be SURE to soap wash the mold quickly afterwards. Or the natural slime coat on the fish, will sink into the plaster, and eventually mold.

Also, if you are pulling waxes directly from the plaster, pull the wax a little early, to prevent locking the wax in the mold. Live/dead fish are more flexible than wax.

Greg

Rosanna

I have heard of people getting 2 plasters apart by shooting compressed air at the interface. I would look in to a company called Kindt Collins (this is out of my head it might not be quite right on) They make all kinds of products for the mold making industry. They might have a sealer/ seperator that works better.

the seperation problems were between the plaster origonal and the 2 part rubber brush on product. shoot, that stuff is hard to get off glass! i could buy the tm, stuff but there are all sorts of upcharges to ship it,hazardous or whatever. i will try thoroughly sealing the plaster origonal next go. i also need to do a few seperator tests on a slick surface. just popped mold two out . i am going to make four to start so i can test several different ideas at once. have shelves , will fill. rosanna