molding casting metal

[michael101]

hello 

im working on the concord stagecoach of model expo

 

and i want to make some upgrade for some little ply pieces 

so i want to cast tin and i need to make a molding for that its a very simple pieces without nothing on that it just for replace 

the wood piece 

 

need advice for making mold  

 

best regards 

Michael.

[shiloh]

Using metal requires heat, how much depends on the material, also you need to determine what the material used shrink rates are and compensate for it in the pattern. Think that most modelers use resin and soft molds. Molding tin would not be difficult to get set up for, might look at some data on the Lost Wax Method, the molds are simpler than sand molds and fit small scale more efficiently. Using sand molds you can pour Iron and brass in large quantities. Someone will be here that casts resin with soft molds that will have some experience to share.

 

Something else you might consider is using Key Stock, I keep it around to cut small parts from, soft and easy to work. With the right size piece of key stock, a file and maybe a fine tooth hack saw, something to hang on to ( leave a handle in the stock you are making your piece from, cut it off as a last step ), and a vice. you can shape something fairly easily.

jud

Edited February 10, 2016 by shiloh

[Moxis]

There are also silicone rubbers that resist high temperatures, up to say 450 deg. Celsius. It is possible to cast tin/lead alloy to the forms made of this material. Just google high temperature silicone rubber.

You may consider also using polyuretane resin for your castings. Does not shrink and can be used in normal temperatures. One good supplier is SmoothOn.

Edited February 11, 2016 by Moxis

[catopower]

Hi Michael,

 

For metal casting, I like the 10 to 1 RTV silicone rubber that Micromark sells. It can take up to 600˚ F or about 450˚ sustained.I tried using stuff from TAP Plastics, which works, but it's thicker and harder to work with I think.

 

I started casting Britannia Pewter, but the melt temperatures are high and so I started using a Tin/Bismuth alloy. I recommend staying away from lead.

 

Rotometals.com has a whole range of low melt alloys and their prices are much better than buying them from Micromark. 

 

Personally, I enjoyed learning the new skill.

 

Clare

[druxey]

I agree with Clare - stay away from lead-bearing pewter. I pour pewter in Micro-Mark's 1:1 RTV moulds with no problem.

[michael101]

wow thank you all !!!

 

I have not read the posts until today 

But I thought on this solution 

 

Melted the tin in the mold of the wood part , on the basis of tin ,

Then I cut the tin around casting

After that sharpened the part ,

and then I drilled the holes ( measured from the damaged wood piece between the holes by a pin ... )

Here are the results :::