How to make a negative cast of a mini

[Aliengod3]

Hello,

I was interested in trying to make small negative casts of pieces of my minis but I am not sure how it is done. I wanted to make negative casts of things like weapons, heads, even barrels. I know it is possible because I have seen it gone by goatman. He made a cast of the Ogre Kingdom Hunter Head for his rhinox rider GD entry. Does anyone know of a tutorial that is good? Preferably one that is not coolmini? Thanks.

 

[freakinacage]

get some gs, powder the piece you are casting with talc. press gs over. leave to cure and then pull of. et voila! for bigger pieces, try silligum

 

[Aliengod3]

Ok lets say I do that and make a negative of a face I like. I press a piece of gs into the negative, but how much gs to a press into it? Enough just to cover the face and then bulk it out or do I use a larger amount? This is what I am having trouble with.

 

[Onis Lair]

If all you want is a face then yes, just press enough GS to fill the hole and make a face. Personally when i make negatives of bases for my own use i use smooth-on RTV and liquid plastic. They use to offer a starter kit that had everything you needed to start making molds, not sure if they still sell those kits. It\'s a little more complicated then GS press molding however.

 

[freakinacage]

just enough to cover/fill it the beauty is you can insert a wire before it dries, which saves drilling later

 

[Einion]

Originally posted by Aliengod3
Ok lets say I do that and make a negative of a face I like. I press a piece of gs into the negative, but how much gs to a press into it? Enough just to cover the face and then bulk it out or do I use a larger amount? This is what I am having trouble with.

I think if you\'re using press-moulds it\'s a good idea to use a harder putty like MagicSculp.

Talc the mould and the surface of a large blob;
press it in, really smooshing it into the mould;
wait for it to nearly set up (an hour +) pull it out gently (heat with hairdryer if necessary);
refine shapes/sharpen details with needles and other tools.

Now wait for it to set and then carve/file/sand it back to a basic head shape, drill for a wire for the neck, superglue in a bit of paperclip or whatever and then sculpt the neck. Then add ears, hair etc.

Einion

 

[krokar]

Does any one know where I can get a vibrating board or make one myself, as im having trouble with the bubbles on my resin casts atm

krokar

 

[airhead]

Resin cast air bubbles:
Whipping air into the mix? Don\'t mix like whisking an omlet.

Mold has too many undercuts? Trapped air is a pain, can you cut an air release channel?

Better than a vibrating table: May want to consider a vacuum table? Pour resin in the mold, set in vacuum jar, pull vacumm to get the air out. Release vacuum to shrink an trapped air that is left. You gotta have slow setting resin to make this work.

Try HirstArts.com to see ideas for a vibrating table. Half or quarter sheet of plywood. Rubber feet, industrial vibrator mounted to the plywood.

 

[freakinacage]

Originally posted by airhead
Rubber feet, industrial vibrator mounted to the plywood.

snigger!

*edit* @ einion, i actually findit better to have a bit of flex when making a mould but prefer something harder to fill it (i find they last longer that way)

 

[Einion]

Originally posted by freakinacage
*edit* @ einion, i actually findit better to have a bit of flex when making a mould but prefer something harder to fill it (i find they last longer that way)

Totally - I was talking about the castings, not the mould. The advantage of moulds in GS is that you can get a bit of wraparound, instead of what\'s basically a \'straight in, straight out\' mould if it\'s in something harder.

Einion

 

[QuietiManes]

\"Try HirstArts.com to see ideas for a vibrating table. Half or quarter sheet of plywood. Rubber feet, industrial vibrator mounted to the plywood.\"

You can also try using a palm sander, rotary tool, personal massager (you know, for sore muscles), drill or anything that vibrates fairly fast. Just stick the mold down to a piece of wood, sticky tac, double sided tape, drop of crazy glue, and then push on the board with the vibrating thing or put the \"vibrator\" against the edge of the board. I have an electric toothbrush that would work. You can fancy it up and create an attachment or mount for the vibrator but it shouldn\'t be needed for smaller molds. I don\'t think anyway.

 

[freakinacage]

Originally posted by Einion

Originally posted by freakinacage
*edit* @ einion, i actually findit better to have a bit of flex when making a mould but prefer something harder to fill it (i find they last longer that way)

Totally - I was talking about the castings, not the mould. The advantage of moulds in GS is that you can get a bit of wraparound, instead of what\'s basically a \'straight in, straight out\' mould if it\'s in something harder.

Einion

sorry!! thats exactly my experience

 

[kramt]

I was reading this thread and this topic really interests me. I am planning to replicate some model parts and I guess casting is the way to go. BTW, what is gs? Any suggestions on how I can replicate a model? Thank you

 

[liamrudel]

Hey guys,

I was wondering is there a thread/article that has a start to finish guide on casting? I\'ve made some greenstuff moulds of a head but they are only one half and I melt sprue and push it into the mould, but I\'d like to make full head casts and maybe use resin to cast the heads from the mould.

Thanks

 

[Einion]

Originally posted by kramt
BTW, what is gs?

GS = Greenstuff. Also called Duro and Kneadatite. Available in the CMON shop here.

Originally posted by liamrudel
I was wondering is there a thread/article that has a start to finish guide on casting? I\'ve made some greenstuff moulds of a head but they are only one half and I melt sprue and push it into the mould, but I\'d like to make full head casts and maybe use resin to cast the heads from the mould.

Google is your friend - just search for resin casting, lots of bits of info out there. If there are any prior threads here the internal search will bring them up.

Einion

 

[Wombat85]

for guides on making molds/casting try here:
http://aldax.com.au/mould_making_tech_tips.htm#money

As for a vibrating table, use a dryer, just sit ur mold, etc on top and turn it on use a toothpick to pop bubbles, good luck. I use a Air vulcanizing silicone rubber for my mold, took 38 trys but figured it out, this is a big learning curve so good luck guys.