[hepburnman]

Hi- I would like to recreate these bird feet and need advice as to how to go about creating a sculpture of them and casting them in bronze. I am wondering how to create the texture and if using wax and the lost wax process is the best way to go. I thought of using blue wax wire (which is all I see available) and whether or not it would be too soft to sculpt/add sufficient texture. The leg thickness is about 5/16" dia.

Advice of what to use and what method to sculpt and cast is appreciated.

Thanks! Mario

 

[yarnart]

I think, if you will use bronze for the stuff, then the best if you use a copper wire "skeleton" for the wax. On another hand, how I see from this picture, these originally were created with sandbox molding, and then probably the original pozitive was made from sculpturing clay (also with some wire skeleton).

 

[hepburnman]

Hi yarnart- Thanks for the reply. A mold based on a clay sculpture (with a wire armature) will require some additional research on my part as to how to produce. A mold based on a wax sculpture was easier for me to contemplate!

Any tips of how to create a mold from a clay sculpture is much appreciated!

Thanks- Mario

 

[yarnart]

https://en.wikipedia.org/wiki/Sand_casting


https://www.reliance-foundry.com/castings/sand-casting#gref




But you can search on it yorself better.

 

[hepburnman]

If starting with a clay sculpture, would the next step be to create a wax positive of this, or rather use the clay sculpture to make an impression in a sand mold? Can the clay sculpture be heated to make it harder and stiffer before making the sand impression?

The bird feet sculpture is like a tree with 4 branches. These branches may not be very stiff. I have also thought about making a rubber mold but how to cut the parting line for the two halves of the mold seems like it would be difficult to do due to these "branches".

 

[yarnart]

No. solid objects, like dried clay, molding directly into the sand. Then the object have to be removed and the the cand mold can be used directly.

 

[hepburnman]

Hi yarnart- I just dont see how a sculpture like a "tree" can be sand-casted if the idea is to do this with one mold. If it were flat, like say a medallion, then I could see making a sand-mold of this. But to cast a bird's foot and leg I would think that this would require at least 2 molds to cast; one for the foot, which is relatively flat, and the other to cast the leg. These separate castings would then have to welded together.

Is there another way to make a single sand mold cast of a bird's foot?

 

[yarnart]

Sand molding of this kind of object also possible, you just have to choose well where will be the seal between the 2 part of molds.
Of course the wax system much easier, but also have more chance to fail. Both way have advantages and disadvantages too. Can you tell me, please, what suppose to be the final dimensions (if we talking from it like a cube) of these bird feet?

 

[hepburnman]

The bird's foot would have the following dimensions:

1) Leg (from foot to top): 4", Thickness: 0.3"

2) Foot: Width (from outside to inside toe): 2.5", Length (Tip of front Toe to tip of back toe): 4"

 

[yarnart]

So it's a 4*4*4 molding. Then you can use the wax methode easily (but you have to count on unsuccessfull casting) so best to make minimum 2 pairs from wax for one pair of bronze. Or you can invest to precision casting (if there is possibility near to you) and work from hard/hardening materials. With the precision casting (in optimal case) you will have a mold which can repeatedly using for cast the same legs again when ever you need new pieces or pairs.

 

[hepburnman]

Hi- I've been slow on this project, in the possibly of producing bronze-casted large bird feet, but I have gotten back at it now and have at least made up an armature. See pics.

Now that I have a foot made out of copper wire I am now trying to decide if I should add either a hard wax, or add a heat harden-able clay to it. I like the idea of dipping the foot repeatedly into liquid wax, to build up thickness, which I would then sculpt/add texture, or else add clay and do the same and then harden. I am trying to decide which would be better for sand casting. Would someone have a experience as to which would be preferred for sand casting?

Also, I am leaning towards sand casting this (actually two feet, as well as the leg portions) in bronze. I like the idea of a silicone mold, so I could more easily reproduce them (lost wax process), should I have difficulties casting, but I am stumped as to how to cut the silicone mold open to release the sculpture. This is a complex shape to me and even trying to make a sand cast to the irregular parting lines would be difficult but doable, I think.

If I decide to dip in wax is there a preferred type? I purchased some some time ago, blue wax sticks, which it says on the box are hard-wax. I may not have enough though to fully submerge the sculpture and would have to buy more if this is OK to use.

Anyway thanks for any comments/suggestions as to how to proceed to try and duplicate the birds feet shown in my earlier posts.

Thanks! Mario

 

[iandandavies]

wax or oil based clay would be best.
lost wax would be by far the best. sand casting would be difficult to impossible depending on how deep the detailing will be.
To mould - make a silicone mould with a supporting mother mould (plenty of videos on this on youtube)
the simplst aproach is is to cut of the back toe and make a simple two part mould of the two pieces. then cast the wax and join them back together. Or you could attempt a more complex 3 part mould if you want to cast a wax as one piece