How do I mold and cast a 1/48 drop Tank?

[Wafu]

Hi,

Made a drop tank in brass and want to make copies, I'm totally new to this so any help would be great.

Ta very.

[Black Knight]

You sure you want to cast in brass.? You'll need a furnace set up and oilsand for the mould. White metal is easier to work with.

Brass need temperature of 900 to 940 degrees C to melt, white metal is liquid at about 235 degrees C, easliy achievable on a portable camping gas cooker. Whit metal is only slightly heavier than brass, and sometimes lighter.

Moulds for white metal can be made of special RTV silcone rubber, for repeatable use.

[Wafu]

Sorry, might not have made this clear.

I have access to a lathe so have made my master in brass, a great medium to work in if your an engineer with a lathe.

Now the next step is making a mold I can use again and again then make at least five or six resin casts.

Hope this clears this up?

[Black Knight]

Sorry, I misread your post.

One can buy RTV [room temperature vulcanising] silicon rubber as a two-part mix. But its expensive if you only intend to make a few moulds.

An alternative is liquid latex, which one either 'paints' on or dips the original. Cheaper than the two-part rubber, but its only good for peelable moulds.

Yet another alternative is polymer clay, better known as Fimo or Sculpey. This a plastic clay which is like plasticene but is hardened by curing in an ordinary oven at 130*C for 15-20 minutes. A block of this costs under £2. As your original is brass it will cope with the curing process.

I've used all three and others.

Here is a mould made in polymer clay, to make French Eagles. The Eagles were cast in resin and I made 12, and the mould is still good;

Unless you intend to get into a lot of casting I'd recommend you try the polymer clay. You need to use a release agent with it and I find olive oil works best.

For resin I mostly use the resin for use with fibreglass for car repairs. Its cheap, but hard and can be brittle. Again better resins are available but minimum quantities are 500ml at about £15 [compared to about £3 for 250ml car repair resin]. The Eagles were cast in the car repair resin.

a start.

hth a bit

[Ali62]

Wafu

I could help if you want me to, you email me some details or a sketch and size of the tank, I can then advise how it can be made and or sprued up, you then make the tank mail it to me. If I make a mould I will get approx. 25 castings though the mould, that way you will have more than enough and then you could sell some off to your club members or BMers................

It is up to you, but best mail me on uc27studio AT gmail.com

cheers Ali