Vw parts of course!
Said Id throw this up for the craic, some of you may be interested in the process so I might as well share given the fact that I took pics of the progress and build as I went.
First off, this line of work is next near impossible get info on so alot of it I had to design up myself and choose the suitable materials too along the way.
Casting is now a dying trade and fully automated around the world in controlled environments.
While Im sure nobody will go to the trouble I have here it may rise some interest as to whats involved, the process, materials, procedures, mould making, melting, design, etc.
I had to do this to figure out a few things I needed to know for my bigger smelter Ill be using to melt the alloy for the cylinder head Im designing.
Using this smaller smelter less heat up times, gas, and raw materials can be used in order to get the feel for molten alloy in general.
Plus, its a bit easier than winding up my bigger smelter which can melt approx 9litres of alloy at a time, where as this one can do 1.25 litres.
Im going to be using this to make a few parts I have in mind for a while, DTH throttle bodies and a few trick intake manifolds being just some of the stuff.
Casting is a pretty simple process, but the finished item all depends on the quality of the mould the metal is poured into.
The main mould types ill be using will be of the sand variety, meaning, you make your pattern part you want in timber(Iroko) and you then strike both your sand mould halves off this pattern. The part shape is then formed in the sand and you can pour in your alloy, that way, ending up with the timber pattern shape, just thats its now alloy.
Its a bit more complex than that but Ill try my best to explain all as I go.
Pattern making is what Im good at as my main ''skill'' is cabinetmaking so making very complex accurate pattern parts is not a problem.
Its important to note that this is not the cylinder head thread, this will be covered in another thread on Club Gti
Ok, so onto the first step of a long road, and that is the smelter itself.
A smelter is basically just a round oven where the crucible is placed in order to melt the charge inside it.
The smelter must be well insulated as the heat inside is in excess of 700 degrees.
The smelter is powered by plan ordinary gas you get for your cooker.
Its all pretty basic, now onto the build...
For the body of the smelter something round is needed, you could use a large diameter pipe but I used a gas cylinder, the walls are 3mm steel and there tough by nature.
I filled it with water to expel any gas still left inside.
Next up, off comes the top with my favourite tool[LOL]
A second ring is then cut off the main body to for a locating ring for lid.
The ring is then split and welded to lid around the outside.
The lid now fits snug back onto main body again.
The lid is turned over and I welded some wire lattice in there to hold in the refractory material a bit better.
The refractory mix consists of,
Perlite
Cement
Sand
Fireclay
Perlite is a natural volcanic material, it is a natural insulator.
Cement is standard cement.
Sand is normal sharp sand.
Fireclay is the cement fire bricks are made from, kinda like normal cement but with a better heat resistance tolerance.
Mixed up
First the base is poured, approx 80mm high.
Then, I wrapped up a bit of Formica to form the inner circle.
Pouring the walls.
Done and tamped.
Onto the lid
A bit of pipe is placed into where the valve was in order to form a vent hole up through the lining. The pipe is removed when lining is set.
Thats the smelter pretty much done now, so next up, onto the crucible.
--------------------------------------------------------------------------------------------------------
The crucible is the cup used to place the metal in that is to be melted.
This is used from start to finish, that is, the raw unmelted alloy is placed in this and stays in here until it melts, the crucible is then removed from the smelter and the alloy poured from it directly into the mould.
So, the material needed for the crucible has to be picked with care, depending on what you are melting, what the part is for, and what properties the finished part has to have all reflect on the crucible material choice.
If poor crucible materials are used some material from the crucible walls can leech out into the molten alloy and effect the alloys properties.
In this case Ill be using stainless steel >316. Its ok for small parts and doesent really have any bad quality's that will effect the final part.
However for the cylinder head, I will be using a pure graphite crucible, graphite poses no threat on the final part qualities, be it strength, structure, or machinable properties.
Obviously On such parts as throttle body's, intakes, and the like, the final properties can afford to be altered a tiny bit as there is no work on these parts as such, and machining of parts is minimal, so, stainless is a perfect choice for crucible material.
The Crucible manufacture.
I got a bit of pipe approx 250mm long with a wall thickness of 5mm, to this I welded a base plate in 6mm.
Rods used are also 316 s/s.
Next, a 'V' is cut for spout
The spout is constructed from two pieces cut to triangle shapes
Spout tacked in place
Finish weld
Next, a ring is needed at the rear in order to tilt vessel in order to pour alloy
Pins are welded to the sides to catch crucible with the pouring tongs
I gave the whole thing a quick sandblast after to remove any oxides or ****.
Sandblasting really works in lifting any dirt or general dirt, a close up of one weld shows surface finish.
It may appear an over kill looking at the scale of the plate thickness, welding, ring, spout, sizes etc, but keep in mind this isent a milk jug and has to with stand very tough conditions for may cycles.
Thats the crucible done, next up the burner tube.
--------------------------------------------------------------------------------------------------------
Said Id throw this up for the craic, some of you may be interested in the process so I might as well share given the fact that I took pics of the progress and build as I went.
First off, this line of work is next near impossible get info on so alot of it I had to design up myself and choose the suitable materials too along the way.
Casting is now a dying trade and fully automated around the world in controlled environments.
While Im sure nobody will go to the trouble I have here it may rise some interest as to whats involved, the process, materials, procedures, mould making, melting, design, etc.
I had to do this to figure out a few things I needed to know for my bigger smelter Ill be using to melt the alloy for the cylinder head Im designing.
Using this smaller smelter less heat up times, gas, and raw materials can be used in order to get the feel for molten alloy in general.
Plus, its a bit easier than winding up my bigger smelter which can melt approx 9litres of alloy at a time, where as this one can do 1.25 litres.
Im going to be using this to make a few parts I have in mind for a while, DTH throttle bodies and a few trick intake manifolds being just some of the stuff.
Casting is a pretty simple process, but the finished item all depends on the quality of the mould the metal is poured into.
The main mould types ill be using will be of the sand variety, meaning, you make your pattern part you want in timber(Iroko) and you then strike both your sand mould halves off this pattern. The part shape is then formed in the sand and you can pour in your alloy, that way, ending up with the timber pattern shape, just thats its now alloy.
Its a bit more complex than that but Ill try my best to explain all as I go.
Pattern making is what Im good at as my main ''skill'' is cabinetmaking so making very complex accurate pattern parts is not a problem.
Its important to note that this is not the cylinder head thread, this will be covered in another thread on Club Gti
Ok, so onto the first step of a long road, and that is the smelter itself.
A smelter is basically just a round oven where the crucible is placed in order to melt the charge inside it.
The smelter must be well insulated as the heat inside is in excess of 700 degrees.
The smelter is powered by plan ordinary gas you get for your cooker.
Its all pretty basic, now onto the build...
For the body of the smelter something round is needed, you could use a large diameter pipe but I used a gas cylinder, the walls are 3mm steel and there tough by nature.
I filled it with water to expel any gas still left inside.
Next up, off comes the top with my favourite tool[LOL]
A second ring is then cut off the main body to for a locating ring for lid.
The ring is then split and welded to lid around the outside.
The lid now fits snug back onto main body again.
The lid is turned over and I welded some wire lattice in there to hold in the refractory material a bit better.
The refractory mix consists of,
Perlite
Cement
Sand
Fireclay
Perlite is a natural volcanic material, it is a natural insulator.
Cement is standard cement.
Sand is normal sharp sand.
Fireclay is the cement fire bricks are made from, kinda like normal cement but with a better heat resistance tolerance.
Mixed up
First the base is poured, approx 80mm high.
Then, I wrapped up a bit of Formica to form the inner circle.
Pouring the walls.
Done and tamped.
Onto the lid
A bit of pipe is placed into where the valve was in order to form a vent hole up through the lining. The pipe is removed when lining is set.
Thats the smelter pretty much done now, so next up, onto the crucible.
--------------------------------------------------------------------------------------------------------
The crucible is the cup used to place the metal in that is to be melted.
This is used from start to finish, that is, the raw unmelted alloy is placed in this and stays in here until it melts, the crucible is then removed from the smelter and the alloy poured from it directly into the mould.
So, the material needed for the crucible has to be picked with care, depending on what you are melting, what the part is for, and what properties the finished part has to have all reflect on the crucible material choice.
If poor crucible materials are used some material from the crucible walls can leech out into the molten alloy and effect the alloys properties.
In this case Ill be using stainless steel >316. Its ok for small parts and doesent really have any bad quality's that will effect the final part.
However for the cylinder head, I will be using a pure graphite crucible, graphite poses no threat on the final part qualities, be it strength, structure, or machinable properties.
Obviously On such parts as throttle body's, intakes, and the like, the final properties can afford to be altered a tiny bit as there is no work on these parts as such, and machining of parts is minimal, so, stainless is a perfect choice for crucible material.
The Crucible manufacture.
I got a bit of pipe approx 250mm long with a wall thickness of 5mm, to this I welded a base plate in 6mm.
Rods used are also 316 s/s.
Next, a 'V' is cut for spout
The spout is constructed from two pieces cut to triangle shapes
Spout tacked in place
Finish weld
Next, a ring is needed at the rear in order to tilt vessel in order to pour alloy
Pins are welded to the sides to catch crucible with the pouring tongs
I gave the whole thing a quick sandblast after to remove any oxides or ****.
Sandblasting really works in lifting any dirt or general dirt, a close up of one weld shows surface finish.
It may appear an over kill looking at the scale of the plate thickness, welding, ring, spout, sizes etc, but keep in mind this isent a milk jug and has to with stand very tough conditions for may cycles.
Thats the crucible done, next up the burner tube.
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