CUTTLEBONE CASTING PART III – Re-Blog Complete With Pictures

 

Monday!  

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.

TOOLS:

Tin Alloy Soldering Wire (4 tubes, 20 feet)

Stainless Steel Spoon

Mini-Torch

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! 

PRE-CASTING PREPARATIONS:

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.

MELT THE METAL / FILL THE MOLD:

*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.

FINAL FINISHING:

 

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.

 

Cuttlebone Casting Part II – Model and Mold Preparation

Good Morning,

 

Wednesday’s are devoted to what’s happening in the studio here at The Alchemists Vessel, and this morning is Part II of the three part series, Cuttlebone Casting.

 

Monday we discussed materials and the very basics of beginning to model and mold the pendant.  Today we are going to continue the project with making the model and creating the mold itself.

 

If you would like to follow along, I recommend a quick review of Monday’s post, Cuttlebone Casting Part I – Materials and Model Making.

TOOLS:
Pencil

Paper

Pin or Sharp Pointy Object

Modeling (Jeweler’s) Wax
Flat File

Jeweler’s Saw

Lighter Fluid

Soft Cloth

Brass Rods

Unsharpened Pencil

Prepared Cuttlebone halves

Last time the design of the piece was decided upon, sketched and cut out.  The sample project shown throughout the instruction will be  simple Cross shape.

This is about 1-1/2″ tall x 1-1/4″ wide.  Sketched in pencil (then traced with ink for a clearer photo), cut out of the paper, this will be the Paper Template from which to trace or “scribe” the design on to the wax block.

PREPARE THE MODEL

Cut out and place your Paper Template on top of the modeling wax and with a pin or other sharp object draw or “scribe” your design into the wax.  Trace the template.  Below is a T-pin, which I use to scribe the design in to the wax.

Note: You can see that the template is a little too long for the wax, you may adjust your design to fit with in the wax area before your trace the design.

Next with a Jeweler’s Saw and a Spiral saw blade (these cut modeling wax best, and straight blades work just fine, too) cut out your model.

Here is the beginning of the wax model.  Using a straight saw blade the block has been cut along the scribed lines in the wax.  Once completely cut out the model will be ready for final preparations.

Once your model is cut out, use a wax file to smooth and true the edges up, keeping them straight and even.  They make specific files for wax, if one is not available a flat jewelers / craft file will work as well.

Using a tiny bit of lighter fluid and a soft cloth, smooth out the surface, corners, and sides of the model.  This will remove any imperfections, nicks and scratches, and smooth the surface for a better impression.  Remember every imperfection will transfer to the finished product.  Be careful, over working the wax will distort or destroy any detail you may have carved into the model.

I have drilled tiny pilot holes in my design, the center hole will house the gemstone, and the others are to keep the design consistent.

NOTE:  I failed to take a picture prior to completing the next steps.  What you see here, is the final model, after it has been pressed into the cuttlebone halves.  The white material is dust from the bone.   Also, I dropped it, as I mentioned the wax is very brittle and I managed to break the arm of the Cross on one side.  However this happened after creating the mold impression!

Whew!  Almost there!

MAKE THAT MOLD

Now the fun starts!  Using one side of your cuttlebone, press your model into the flat surface of the bone.  The bone is soft, use gentle even pressure.  Next place the other half of the cuttlebone on top of the wax model and other half of the bone-mold and press the two sides together.  GENTLY!  If you press too hard the cuttlebone will break and another one will have to be prepared before continuing.  The wax model is now embedded in the cuttlebone.  It does take some pressure, and you can hear the model sinking into the surface of the cuttlebone.  The halves do need to touch, but press the wax into them enough for a well-defined impression.

With a pencil, mark several places on the outside of the bone so you can align the halves later.  This is important, the sides of the mold must match up for the inside to cast properly.

Remove the model.  The impression will be left behind.  This model may be used again to make another mold.

 

Here you can see the impression the wax model has made in the bone, along with the natural striated patterns of the bone itself, they are distorted by the the impression of the cross.  (The other side of the cuttlebone looks just like this).

If desired, very, very carefully sand the impression for better definition.  Do not overwork the area or you can distort the impression.

ADD SPRUE CHANNELS AND VENT GATES

Choosing one side of the mold, lay it flat and using the end of a pencil (not sharpened) create a SPRUE CHANNEL by gently pressing the pencil into the bone, just above and at the edge of the impression.  What’s a sprue channel?  It is a channel that allows the material you’re pouring to enter the mold for casting.  Make sure that this just touches the edge or of your model impression, but not so much to distort your design.  (Simon didn’t say to remove the pencil).

Next using brass rods or something with a smaller diameter than the pencil create VENT GATES.  What’s a vent gate?  It is a channel that will allow air to escape the mold during the casting process.  Just like you did with the pencil, using two (2) Brass rods (or tool) lay them just at the end and edge of the arms of the Cross.  These should also just touch the edge of the impression.  With the pencil and then the rods in place, place the second half of your mold over the pencil and rods and press down, keeping in mind to align the pencil marks on the outside of the cuttlebone.  The channels must be created in both sides of the mold.  Take the halves apart, remove the pencil and rods.

Are you still with me?  Still want to make a piece of jewelry?   Alrighty then!  Here we go!

Now match up the halves with the lines you made on the outside.  Find the Sprue Channel. Very carefully mark the top of the mold (both sides), on either side of the Sprue Channel.  This is where you will cut the SPRUE HOLE.  What’s a sprue hole?  It is a larger opening in the mold, which allows you to pour material into the Sprue Channel and into the mold.  This makes it easier to pour the material from whatever you have melted your material in, into the mold itself.  If you try to aim for the Sprue Channel you will wind up with material on the outside of the mold and possibly severe burns.  Molten Metal is HOT HOT HOT!  This project only gets up to about 400 degrees, but that can still do some serious damage!  Be careful.

Here you can see the Vent Gates, Sprue Hole, Sprue Channel, and the pencil marks I made on the outside of the bone to align the pieces.

Now align the Mold again.  Using Mold Wire, Rubber bands, or other type of binding (I do not recommend Duct Tape or other adhesive strips or bindings), match up the halves and secure (close) the mold.

The photo above is the closed mold, with Rubber band binding.

You just made a mold.  COOL!

WHEW!

Set the mold aside, some place safe and dry.

The preparations are now done and the mold is ready to begin casting the piece.

Take a break, have a little sit down and enjoy some tea, coffee, a beverage, or snack of your choice!  You’ve earned it!

Next time.  Part III – Casting the piece. 

Thank you for stopping by and having a look.

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