Metal Melter

[DAPPH]

Not remotely ! But, then again, I tend to cast in aluminium alloys or zinc. Brass or bronze need a heck of a lot more heat to be pourable, and are an all round PITA....
Using petrobond, but a silica sand/sawdust/linseed oil mix for cores. Bit of pilchard oil in the stuff makes it a touch less tenacious...

Could you cast in alu then use the hard alu casting to make the brass mould ?

Do TIG bronze welding sticks ( can't think of the right name just now ) melt at a lower temp and flow better than brass if you use SIF BRONZE flux ?

 

[Kram]

TIG silicon bronze is higher temp than brass.
We were using red plumbing brass which is a higher temp anyway, but the problem is really just the original furnace design.

The shape cant be with drawn from the sand , really only suited to investment casting where the form is burnt out.
If the text ring was seperate, that part is easy to sand cast.

I plan to have another go at this probably in a couple weeks I will get the furnace running again.

Also looked at trying induction again by getting a quartz liner for graphite cruicible but Im not convinced it would help the temperatures much.

 

[DAPPH]

TIG silicon bronze is higher temp than brass.
We were using red plumbing brass which is a higher temp anyway, but the problem is really just the original furnace design.

The shape cant be with drawn from the sand , really only suited to investment casting where the form is burnt out.
If the text ring was seperate, that part is easy to sand cast.

I plan to have another go at this probably in a couple weeks I will get the furnace running again.

Also looked at trying induction again by getting a quartz liner for graphite cruicible but Im not convinced it would help the temperatures much.

Interesting .
Can you varnish spray the item and dust the form with investment powder several times to get a thin bubble free coating then pour in Plaster of Paris or a liquid investment then melt the wax out in the oven and use a low heat metal that liquifies about 450 oC such as tin . I suppose a gold coloured acrylic could also be poured in a vibrbrted hollow form . Have you tried magnesium alloy car wheels as a source of low heat metal ?

 

[Kram]

He wants it to be brass. It wont look the same as alu.

There was no problem getting fine detail if you look at the other attempts.

 

[oldbikedavey]

Could you cast in alu then use the hard alu casting to make the brass mould ?

Do TIG bronze welding sticks ( can't think of the right name just now ) melt at a lower temp and flow better than brass if you use SIF BRONZE flux ?

Brass melts a good deal hotter than aluminium, so that's a non - starter.
As regards the melting points of the various brazing rod compositions, they will be known by the manufacturers, but are typically between 800 and 900 C, roughly.
Melting cuprous alloys requires either covering flux or a deoxidiser, of you'll just get a load of black oxidised crud...

 

[oldbikedavey]

He wants it to be brass. It wont look the same as alu.

There was no problem getting fine detail if you look at the other attempts.

Aluminium bronzes look quite nice, and are relatively amiable in casting...

 

[Onoff]

He wants it to be brass.

Sounds like a fussy sod!

There was no problem getting fine detail if you look at the other attempts.

Just to recap on those for new readers:

https://flic.kr/p/2nSu4qK

https://flic.kr/p/2nYs1Q6

https://flic.kr/p/2nYsZby

The head came out amazingly well.