Monday, September 3, 2012

CUTTLEBONE CASTING PART III - Re-Blog Complete With Pictures


I hope every one is still enjoying their Holiday Weekend.

The first time this was posted I was experiences some technical difficulties, and after consulting an iMac savvy friend,  I have picture upload once again!

If you would like to follow along or have just started to read here, may I suggest reading (or taking a brief scan)
Cuttlebone Casting Part I - Materials and Model Making
Cuttlebone Casting Part II - Model and Mold Preparation

PART III Casting the project.
Tin Alloy Soldering Wire (4 tubes, 20 feet)
Stainless Steel Spoon
Prepared Cuttlebone Mold
Vice Grip or Prop
Safety Gear
Goggles / Glasses
Gloves, leather shoe strings (something to wrap the spoon handle) 

NOTE:  The sample casting shown used 2 to 2-1/2 tubes of Tin Alloy Solder, your project may require more or less depending on size of the model and depth of the impression.

SAFETY FIRST!  This lesson consists of playing with fire, and I mean literally.  Temperatures reach 400 degrees and possibly higher!  Be aware of your surroundings and your work area!  Remove any and all distractions and make sure you have an uninterrupted block of time in which to work.  Although this portion of the process is fairly quick, you must pay attention to what you are doing!  Turn off your cell-phone, send the kids outside to play, give the hubby a “Honey-Do” list and feed the dog; you must be and remain focused!

Last time we made a wax model and a mold from simple and easy to obtain materials.  Today we are going to complete the process and show the steps for actually casting the piece.  The step-by-step process for creating a mold may be read in CuttleboneCasting Part II – Model and Mold Preparation.

The cuttlebone mold is now ready for molten metal.  Cuttlebones are naturally heat resistant.  This means that they can withstand high heat without distorting in shape, and make wonderful molds for just that reason.  They are also a completely natural tool with no added chemicals and won’t harm the environment.  Eco-friendly jewelry creation, that’s a plus! 

Prepare your work area.  Make sure it is free of anything flammable and fluttery that might catch fire or drift into the molten metal.  Place your mold in the Vice Grip or other object you have chosen to keep it steady and upright.  Get your spoon (or whatever you’re going to use to melt the metal in), torch, and tin alloy lined up, ready to go, and easily accessed! 
**TIP:  Trim the tin alloy coils into smaller pieces; this will make melting and adding it to the already melted material much easier.
NOTE:  Unlike other casting processes that use high-speed centrifuges or kiln (oven) burn out cycles (Lost Wax Casting) to distribute the material to the mold, all that is working here is gravity!  Pouring the molten metal into the mold is like filling a glass with sand, the material will be layered as you pour it into the mold.

Here I have the cuttlebone mold in a prop to keep it upright and steady as material is poured.  Closed with Rubber bands and waiting for metal to be melted and poured.

*The Spoon will reach temperatures of up to 400 degrees (the melting point of the tin alloy is 374-degrees), USE PROTECTIVE MEASURES!  Leather gloves or wrap the end with leather shoestrings to keep the heat away form your hands and fingers.

Begin by adding a small amount of the Tin Alloy to the spoon.  Cut bits off the coil first to make this easier.  Let it sit in the bowl of the spoon.  Do not try to melt the whole coil all at once.   Using a mini-torch, hold the spoon just above the flame and melt the metal in the spoon, continue to add bits of metal until the spoon is full.

The flame has not been turned on for these pictures, that would be hazardous to my heath and the I'd burn the house down.  These are to show the spoon's position it should be held up and away from the nozzle of your torch and the flame allowed to heat the bowl of the spoon from underneath.

Because the soldering material is a tin / rosin core alloy, you will see the rosin left behind in the spoon, and some smoke may rise as the rosin burns away.  That is the brown discoloration on the spoon and mold.  Rosin comes from trees and is a brittle solid form of resin, it is used as a flux in some soldering materials to help the metal melt and flow at an even rate.  This discoloration will not appear on your piece, this is left behind after the melting process. 

NOTE:  The molten metal will pool in the bowl of the spoon.  Adding pieces of material closer to the pool will help it to melt and incorporate into the ever growing puddle of metal.  It will slide around in the spoon hold the spoon steady while melting is in process. 

Coil melting into pool of molten metal
Melted puddle of metal.
Continue to add pieces of the Tin Alloy until the spoon is full, or until you think there is enough metal to fill the mold.
Carefully pour the contents of the spoon into the Sprue Hole and down the Sprue Channel.
Repeat the melting and pouring process until your mold is full, if necessary.  You will have to look through the Sprue Hole and do a little guessing here to be sure that the material has filled the mold (impression) completely.  You DO NOT want to fill the Vent Gates or Sprue Channel, just enough metal to fill the mold of the Cross.

Instant Gratification…. Well almost.  After the mold is full, wait a full ten to fifteen minutes for the metal to solidify and harden.  The mold will also be cooling down during this time, making it a little easier to handle.
Here you can see the burn mark on the top of mold, where the spoon touched the surface of the cuttlebone.  The cuttlebone sits in its prop cooling down while the metal is solidifying.

Once time is up, carefully remove the binding from the outside of the mold, unwind the wire, slip off the rubber bands (whatever was used) gently, keeping the mold closed as you do this.  If you used Duct Tape (and I told you not to) you will have to cut it away with a razor-blade where the two halves of the mold meet and split the mold open like a book.

Well looky there!  You have a metal pendant!  TAH-DAH!

The tin alloy is soft enough that you can drill a hole in the top of the cross using a drill bit and your hand for a bail to be glued (soldered) into place.

Using Sandpaper and a file, will "clean" up the casting.  Some of the metal over flowed the mold impression and will have to be removed.  You can also see the natrual pattern of the cuttlebone has left surface impressions as well.  These may be left as is or sanded, filed and polished.

Cleaned, sanded and filed casting. The bone's pattern has created a line in the  surface of the cross

To complete my pendant, I will seat the simulated Garnet into the center hole of the Cross.  Using a brass rod that I have ground to a 45-deegree angle at one end, I will finish the pilot hole for the gem and seat it in to place.  Using a craft knife or razor blade, I will then create PRONGS by scraping some of the metal from the Cross up and over the gemstone in four evenly spaced places around the stone's setting.
Complete Cross before scrapping prongs and final polishing.
Although this will leave dents in the exterior of the Cross surface, it will help secure the stone into place.

 After the gemstone setting is complete I will use a Polishing Cloth (these have chemicals embedded in the material) and gently rub the surface of the piece, polishing it and giving a little shine.

It is now ready to be displayed or worn on chain or lanyard.

Thank you so much for stopping by and having a look, and if you have followed the whole series, thank you for sticking with us.  We hope you have enjoyed this brief look in to one of the many casting processes available and used for jewelry-making.

The Alchemists Vessel would  like to wish you a pleasant day.

**Want something like this, but don't want to do it yourself?  Custom work is available.  All custom molding projects begin at $50.00 this includes Design materials and Mock Up of your custom piece before casting.  Precious Metals are available for this process.

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