Brass Wren

[outofthefire]

I've been contemplating casting something for a while (I bought the clay for the greensand over 5 years ago ) and finally decided the other day to crack on. I glued three pieces of wood together and whittled a stylized wren. Trying to get it as smooth as possible it's been filled and painted a few times. I made some greensand with bentonite clay, silver sand and water and made a container to cast it in. I went with brass for my first attempt cos we've loads of scrap and heated it up with the forge in a crucible made from the bottom of a disposable gas bottle. I don't know if my vent hole was too small or the sand is too wet, but after I'd got a bit of brass in it blew some back out. All in all I'm pretty happy with the result for a first go even if it is ugly. Next up ally and copper bronze, I'm not keen on the brass the zinc is a too smokey and I'm sure partly responsible for some of the pitting, I've used ally bronze in an open mould before and it was a lot cleaner.

 

[tom2207]

Its a great shape ,,, if you get the casting right , and do a production run ,, put my name on the list. Id buy one.

 

[TechnicAl]

Be careful of water....1 litre of water makes 1600 litres of steam....so most metals melt at a temp that will create steam immediately they contact water.........steel is very dangerous as its whqt 1500/1600 oC....the steam will create an explosion.....your bit is only small but it can still burn

 

[outofthefire]

Be careful of water....1 litre of water makes 1600 litres of steam....so most metals melt at a temp that will create steam immediately they contact water.........steel is very dangerous as its whqt 1500/1600 oC....the steam will create an explosion.....your bit is only small but it can still burn

Luckily I was being careful because it was on the back of my mind, trouble is all the recipes I've seen for bentonite green sand use water and no mention of whether they leave it to dry. I'm guessing that's why commercially it's oil bonded sand. I think for my 2nd go I'll leave it over night and put two vent holes in

 

[The_Yellow_Ardvark]

Few tips.

The filler hole, can you make a depression twice the diameter of the pouring hole. This will help slow the pour down into a smoother stream.

The vent hole, should be the same as the inlet, with out a depression.

Prick the sand to allow gas to escape, it doesn't matter if you break in, that git can be cut off.

Warm the mould, made sure it is as dry as you can.

Hope this helps.

 

[The_Yellow_Ardvark]

Luckily I was being careful because it was on the back of my mind, trouble is all the recipes I've seen for bentonite green sand use water and no mention of whether they leave it to dry. I'm guessing that's why commercially it's oil bonded sand. I think for my 2nd go I'll leave it over night and put two vent holes in

The sand should be wet enough to form a ball when squashed in the hand.
Yet break clean with not mess.
Be easy to shape, with out crumbling or breaking.

Use 2mm wire to add more gas vent holes.
The riser will allow the metal to fill the mould and push the air out. The gas vent holes will allow stream etc to escape.

 

[outofthefire]

Few tips.

The filler hole, can you make a depression twice the diameter of the pouring hole. This will help slow the pour down into a smoother stream.

The vent hole, should be the same as the inlet, with out a depression.

Prick the sand to allow gas to escape, it doesn't matter if you break in, that git can be cut off.

Warm the mould, made sure it is as dry as you can.

Hope this helps.

I tried making a depression, but it wasn't twice as wide. I thought starting with something small would be easier, but it brings its own problems. The next time i'll angle the vent more to give me more room around the fill hole, and try your other suggestions

The sand should be wet enough to form a ball when squashed in the hand.
Yet break clean with not mess.
Be easy to shape, with out crumbling or breaking.

Use 2mm wire to add more gas vent holes.
The riser will allow the metal to fill the mould and push the air out. The gas vent holes will allow stream etc to escape.

It forms a ball, but it is still quite sticky so I reckon it's too wet.

 

[TechnicAl]

When I worked in a Foundry we used silica sand, mixed with Sodium Silicate (concrete sealer) which reacts with CO2 in the atmosphere or more rapidly by blowing CO2 through it..........That sets it and then it can be baked

 

[Parm]

When I worked in a Foundry we used silica sand, mixed with Sodium Silicate (concrete sealer) which reacts with CO2 in the atmosphere or more rapidly by blowing CO2 through it..........That sets it and then it can be baked

they now use phenolic resins mixed in the sand that are amine cured

 

[TechnicAl]

they now use phenolic resins mixed in the sand that are amine cured

They used that as well for smaller stuff like golf club heads........I called it pre-glued....so I couldnt describe it....well done

 

[MysterG]

Nice!

We had a Wren fly into the conservatory last week, I mean it flew through the open doors not into the glass.
That said it did proceed to then fly into the glass from the inside. Was sat stunned for a quite a few minutes, but came round okay and flew off.

 

[The_Yellow_Ardvark]

I tried making a depression, but it wasn't twice as wide. I thought starting with something small would be easier, but it brings its own problems. The next time i'll angle the vent more to give me more room around the fill hole, and try your other suggestions

Pour at a constant rate, do not stop until the riser is full. If it leaks keep going.
Don't stop, don't change speed.
A good sign is the top of the riser, it should look like it was a smooth pool before it was cold.

It forms a ball, but it is still quite sticky so I reckon it's too wet.

Yes sounds like it.
To wet is bad, to dry can be rammed firm

 

[TechnicAl]

Nice!

We had a Wren fly into the conservatory last week, I mean it flew through the open doors not into the glass.
That said it did proceed to then fly into the glass from the inside. Was sat stunned for a quite a few minutes, but came round okay and flew off.

I had the same....it flew into the closed patio door and crashed to the floor.....I went to pick it up but it flew onto a chair back and sat there maybe half an hour....them flew off...........We have a wren nest in the garden every year, this is the first time in years that she has raised her young....I usually find them dead under the nest

 

[pedrobedro]

I had a wren build a nest in the lean to at the back of the house, came to roost init every night but never had any female interest in it. Apparently they build several nests than the hen goes round and picks her favourite to nest in.

 

[The_Yellow_Ardvark]

I like this type of WREN.

 

[TechnicAl]

View attachment 246084

I like this type of WREN.

I like the Yorkshire Brass

 

[The_Yellow_Ardvark]

I like the Yorkshire Brass

This?

 

[Barking Mat]

With us it's stupid pigeons.

 

[Morrisman]

Sinker and Ri ser. Isn’t that the name for the holes you fill by, and let the air escape from? We did some foundry work way back in my early days, can’t remember much more than Cope and Dreg, Greensand, and that molten aluminium hurts if you drop some inside your boot.

 

[The_Yellow_Ardvark]

I like the Yorkshire Brass

Sinker and Ri ser. Isn’t that the name for the holes you fill by, and let the air escape from? We did some foundry work way back in my early days, can’t remember much more than Cope and Dreg, Greensand, and that molten aluminium hurts if you drop some inside your boot.

Sinker and riser was what I was educated way back then.
But now I know the filler port as the fill or pour port.
The Riser is still the same.

But way back when the used iron to make cannon balls.
The spues, riser and pour were known as "gits"

Hence the term
The Useless Git.