Casting brass

[GraemeVW]

You can cast a bronze head for your velocette

Now that is a VERY good point I hadn't considered!

I guess it's not impossible his skips have bronze. He deals with waste management from all kinds of industry and its mainly located in Sheffield. I know they sort all the waste.
I'll see if I can have a word with him.

 

[frank horton]

isn't brass and copper mixed "Bronze".....? ratio ?????
GraemeVW
I keep thinking about it....as I alwas want stuff cast for v/old cars etc...(parts unavailable)
luckily there's a custom glass maker near me that does a little casting in Bronz/Ally will try there first.....
also
an artist friend in France sent all his patterns to INDIA and had it all cast there......he said it was cheaper and less worry (neighbours) to send it there....

 

[julianf]

isn't brass and copper mixed "Bronze".....? ratio ?????
GraemeVW
I keep thinking about it....as I alwas want stuff cast for v/old cars etc...(parts unavailable)
luckily there's a custom glass maker near me that does a little casting in Bronz/Ally will try there first.....
also
an artist friend in France sent all his patterns to INDIA and had it all cast there......he said it was cheaper and less worry (neighbours) to send it there....

I don't know if this is what you're asking but brass and bronze are quite different.

Brass is copper plus zinc
Bronze is copper plus tin

I don't think there is a simple way to convert brass to bronze. Probably easier to start with copper and add tin?

 

[doubleboost]

Bronze gear wheels and gate valves are decent stuff .
Aluminium bronze as used in bearings is good to cast but can be difficult to machine
I used

 

[GraemeVW]

Bronze gear wheels and gate valves are decent stuff .
Aluminium bronze as used in bearings is good to cast but can be difficult to machine
I used

What I'm planning shouldn't need and machining after. Maybe a little filing and soldering though.

I could maybe convince myself that aluminium would be ok, but deep down, if always know if wanted brass.
For authenticity the parts should probably be guilded iron, but that ain't happening!

 

[The_Yellow_Ardvark]

Brass is a pain to cast.
You have to know grade of brass beforehand. This is they shrink at different rates, melt at differant temps and can leech the copper.

If you know that, make a mould.
Using fine sand, or if you can find casting sand.
Add sand to casting box. Made the impression, cut the pour hole, vent hole.

There are many videos on the net on crucibles, I have used old Steel co2 extinguishers in the past.
Fuel.
Hard wood charcoal, made from green hard wood. Forced air to get it hit.
Bellows or a ducted fan. I used both.

Add small amount of brass to crucible, heat until it melts into a pool.
As that is going on pre warm the next charge. Add slowly.

Still with a willow stic.
Pour into the mould.

Safety.
Common sense is the best way.

 

[GraemeVW]

Brass is a pain to cast.
You have to know grade of brass beforehand. This is they shrink at different rates, melt at differant temps and can leech the copper.

If you know that, make a mould.
Using fine sand, or if you can find casting sand.
Add sand to casting box. Made the impression, cut the pour hole, vent hole.

There are many videos on the net on crucibles, I have used old Steel co2 extinguishers in the past.
Fuel.
Hard wood charcoal, made from green hard wood. Forced air to get it hit.
Bellows or a ducted fan. I used both.

Add small amount of brass to crucible, heat until it melts into a pool.
As that is going on pre warm the next charge. Add slowly.

Still with a willow stic.
Pour into the mould.

Safety.
Common sense is the best way.

Lucky, it doesn't really matter how much they shrink, the parts are not size sensitive. Purely decorative.
I'd guess, if I was going to cast brass, if end up with loads of old plumbing fittings, or maybe front aprons from open fireplaces. They seem to be the most common sources of scrap brass in my life.

 

[The_Yellow_Ardvark]

Lucky, it doesn't really matter how much they shrink, the parts are not size sensitive. Purely decorative.
I'd guess, if I was going to cast brass, if end up with loads of old plumbing fittings, or maybe front aprons from open fireplaces. They seem to be the most common sources of scrap brass in my life.

Plumb fittings would be the best bet, cheep and to a BS standard.

But they can take some effort to bring to a shine.

 

[Kram]

I have only had a few attempts in aluminium. Difficult to get low porosity but cast does turn nice.

Brass will fume zinc so respirators are needed. I have a few kg of clean brass swarf and scraps to try one day.

My attempt with smokeless charcoal worked but its messy and melted both the perlite lining and the steel tip of my heat gun. You need a proper refractory lining for coals. Propane or electric would be much cleaner.

 

[GraemeVW]

Plumb fittings would be the best bet, cheep and to a BS standard.

But they can take some effort to bring to a shine.

The parts probably won't be polished either, maybe the highlights will get a little bit. They want to look aged.

 

[GraemeVW]

I have only had a few attempts in aluminium. Difficult to get low porosity but cast does turn nice.

Brass will fume zinc so respirators are needed. I have a few kg of clean brass swarf and scraps to try one day.

My attempt with smokeless charcoal worked but its messy and melted both the perlite lining and the steel tip of my heat gun. You need a proper refractory lining for coals. Propane or electric would be much cleaner.

I have plenty of clay, and vermiculite, boards and fire bricks from the inside of multi fuel stoves. I was hoping to use those in some way.

I've not really looked into what to make to provide the heat yet though, early days still.

 

[bourbon]

If you can't find a willow stick, throw an aspirin into it

 

[GraemeVW]

If you can't find a willow stick, throw an aspirin into it

If you say so!

 

[dyno-tron]

If you can find a couple of old gearboxes at the scrap place you can get some bronze from them, gear selector forks, usually quite chunky pieces.

 

[GraemeVW]

If you can find a couple of old gearboxes at the scrap place you can get some bronze from them, gear selector forks, usually quite chunky pieces.

Good point. I have friends in the motor trade too. I should probably pick up old gearboxes anyway, aluminium from the cases, and I bet the shafts inside are good steel.

 

[dyno-tron]

Good point. I have friends in the motor trade too. I should probably pick up old gearboxes anyway, aluminium from the cases, and I bet the shafts inside are good steel.

Yep, lots of shafts & pins made of quite tough steel, gears for sculpture work too :-) and synchro rings are usually bronze (or some other type of yellow metal) . May take some detective work to dismantle!

 

[brightspark]

if you know any plumbers a lot of valves are made of bronze

 

[GraemeVW]

Yep, lots of shafts & pins made of quite tough steel, gears for sculpture work too :-) and synchro rings are usually bronze (or some other type of yellow metal) . May take some detective work to dismantle!

I thought the proper tool to dismantle was the BFH?

 

[GraemeVW]

if you know any plumbers a lot of valves are made of bronze

I know a few, but all domestic, so maybe not much use.

 

[doubleboost]

Find your local gear box repair specialist .
They save selector forks and synchro rings .
Beer money for Christmas usually .
If you approach in the correct manner (money in hand).
They will fix you up .
Alloy bronze is the material they use casts very well nut not nice to machine .
Just price scrap bronze per kilo and offer them a bit more .