How To Cast (1 Viewer)

[TomB]

I would like to try casting a figure....the only material I can use (because nothing else is available at so called craftshop) is plasticine and Instant resin (cannot always get the resin)...I can make a mould from the plasticine...the type of plasticine I use.. does not require a release element.....What I need to know is,,,the very basic...how too....where to leave channel to pour into mould,,,how to break up figure for casting....the whole deal really....can anyone give me a clue please...TomB

 

[christopher]

If I understand you correctly, so you want to make a mold. my question is for what material is the figure? Resin or tin? For both, I recommend heat resistant silicone caoutchouc. at a walking figure with base I recommend the gate at the bottom of the base. Without base on both soles. Do not forget the air vents on the side of the figure, and so you can fully phased out with tin or Resin
Merry X-mas and a happy new year
Chris

 

[theBaron]

I would like to try casting a figure....the only material I can use (because nothing else is available at so called craftshop) is plasticine and Instant resin (cannot always get the resin)...I can make a mould from the plasticine...the type of plasticine I use.. does not require a release element.....What I need to know is,,,the very basic...how too....where to leave channel to pour into mould,,,how to break up figure for casting....the whole deal really....can anyone give me a clue please...TomB

Hi, Tom!

Add pour gates where it makes the most sense, and since you're using resin, you might want to have one large casting gate, with all parts coming off it. I notice that a lot of commercial manufacturers will do that. Verlinden's 1/48 US Navy WWII pilots, for example, have most of the parts on a single pouring gate. But as an example, maybe put the pour gate at the bottom of the figure's feet, or at the top of his head.

Breaking a figure down really depends on how few undercuts you need to make the mold, and to eliminate seam lines. A figure standing at attention, arms at his side, might not need to be cut at all. A figure running might require cutting the arms at the shoulder, and the legs, too.

That's really just a guideline. You should look carefully at your master, picture where the seams would be if the piece were laid in a plane. If anything extends up from that plane, and you don't cut the figure, you need to build up one have of the mold to match the shape, which makes the mold mor complicated.

Hope that helps, prosit!
Brad

 

[Martin Tabony]

Hi, Tom!

Add pour gates where it makes the most sense, and since you're using resin, you might want to have one large casting gate, with all parts coming off it. I notice that a lot of commercial manufacturers will do that. Verlinden's 1/48 US Navy WWII pilots, for example, have most of the parts on a single pouring gate. But as an example, maybe put the pour gate at the bottom of the figure's feet, or at the top of his head.

Breaking a figure down really depends on how few undercuts you need to make the mold, and to eliminate seam lines. A figure standing at attention, arms at his side, might not need to be cut at all. A figure running might require cutting the arms at the shoulder, and the legs, too.

That's really just a guideline. You should look carefully at your master, picture where the seams would be if the piece were laid in a plane. If anything extends up from that plane, and you don't cut the figure, you need to build up one have of the mold to match the shape, which makes the mold mor complicated.

Hope that helps, prosit!
Brad

I wouldn't use Verlinden as a guide, they probably use a similar set up to me, which includeds a degassing chamber for the resin and a pressure pot for casting!
There are some good web sites that can show you the basics. Sculptor.org, resinadict. etc.


Martin

 

[theBaron]

I wouldn't use Verlinden as a guide, they probably use a similar set up to me, which includeds a degassing chamber for the resin and a pressure pot for casting!
There are some good web sites that can show you the basics. Sculptor.org, resinadict. etc.


Martin

Hi, Martin, the example isn't as import as the design. I'm talking about a single casting gate at the top of the mold, with all of the pieces in the mold coming off it. It would form a long rectangular piece. For example, I've got 54mm wine bottles, so they're on a single block. I agree with you, that using degassing and pressure reduces the chance of bubbles in the casting and the chance of any short-shot. I use gravity, just as with casting in metal.

Prost!
Brad

 

[TomB]

If I understand you correctly, so you want to make a mold. my question is for what material is the figure? Resin or tin? For both, I recommend heat resistant silicone caoutchouc. at a walking figure with base I recommend the gate at the bottom of the base. Without base on both soles. Do not forget the air vents on the side of the figure, and so you can fully phased out with tin or Resin
Merry X-mas and a happy new year
Chris

Thanks for the reply....I will look into the airvent and find out the best position for them....I have had limited success at simple casting..a couple of air vents might elp...thanks ...TomB

 

[TomB]

Hi, Tom!

Add pour gates where it makes the most sense, and since you're using resin, you might want to have one large casting gate, with all parts coming off it. I notice that a lot of commercial manufacturers will do that. Verlinden's 1/48 US Navy WWII pilots, for example, have most of the parts on a single pouring gate. But as an example, maybe put the pour gate at the bottom of the figure's feet, or at the top of his head.

Breaking a figure down really depends on how few undercuts you need to make the mold, and to eliminate seam lines. A figure standing at attention, arms at his side, might not need to be cut at all. A figure running might require cutting the arms at the shoulder, and the legs, too.

That's really just a guideline. You should look carefully at your master, picture where the seams would be if the piece were laid in a plane. If anything extends up from that plane, and you don't cut the figure, you need to build up one have of the mold to match the shape, which makes the mold mor complicated.

Hope that helps, prosit!
Brad

Thanks for the reply...contains a few clues which I needed to know and give's me some basic's to work on...Thanks...TomB

 

[TomB]

I think you're going to have to mail-order a casting set. Plasticene doesn't harden enough to allow a master sculpt to be removed without causing distortion to the mould. Silicone rubber- aka RTV rubber- is the best way to go. There are a number of companies offering kits by mail- these guys are on your continent, at least: http://www.rowetrading.com.au/ They carry Smooth-On products, some of which I use for casting in pewter. They make a large selection of resin-casting kits for us hobbyists, too. The Rowe site isn't very informative. I'd go to the Smooth-On home site (http://www.smooth-on.com/). They've got some tutorial videos and detailed descriptions of their products. And this shows a comprehensive guide they sell: http://www.smooth-on.com/Getting-Started-In/c4_1141/index.html. I'll dig up some other stuff for you, but this should be enough to get you in trouble ^&grin. It can be as engrossing an activity as sculpting is....
Here's how I do it for metal. The method's the same if you are casting in pourable resin. http://www.treefrogtreasures.com/forum/album.php?albumid=1022

Thanks for the reply...there is a lot of info and reference's there....I have had a busy day with grandkids and I am stuffed at the moment so I will have to come back and work though your post and webb sites....ref plasticine....your correct...one cast only...but I am improvising with what I can easily get locally to get an idea of casting simple things....if I find I like casting , then I will have to go through the internet to obtain the proper materials.......and advice.....thank you...TomB