FreeShip- Injection Wax, Freeman Flakes, Blue- (Prompt rebate on orders with 3 or more FreeShip items!)

DESCRIPTION-> Click "Learn more about this item" for article & instructions!
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Injection wax is widely used in the arts, in jewelry/adornment, small to medium sized sculptures, and components of other arts. Injection wax needs some type of tough wax that doesn't break easily when handled during spruing and venting (but still hard enough to hold detail). Toughness is a mix of tensile strength, ductility, shock resistance, and flexibility. At the other end of the spectrum is hardness, in this case the ability to retain details. This is a made to be flexible injection wax, especially good for small jewelry reproduction because it will bend slightly before it breaks (it will return to it's unbent shape). It is a blend of toughness and hardness and has more plastic polymers. This wax has the hardness to be touched up but is still tough enough to not break easily. Here's what the manufacturer has to say about this injection wax: "...renowned for its high pattern detail, rapid wax solidification, minimal shrinkage, excellent flow, and low ash content (.003%) enabling the cleanest burnouts and most accurate reproductions possible. All are designed for platinum, gold, and silver, as well as industrial and dental alloys.
Please note that these formulas are unique to the Freeman Flakes line and are NOT sold under any other brand or product line.."

I'd like to mention a variation I used sometimes to make multiple wax models that do not shrink but are actually slightly larger than the original model that was used to make the rubber mold (which counteracts the shrinkage of the metal casting made from that slightly larger wax model), but if you're interested go to the bottom section of this description. It does not merit description up here because of some disadvantages, so I've put it at the very bottom of this description.

Injection wax has specific properties which depend somewhat on the purpose of the final metal product. It is widely used in the arts, in jewelry/adornment, small to medium sized sculptures, and components of other arts like ceramic add-ons or whatever else imagination can conjure. It is also used in practical mechanical industries for machinery parts and consumer item components. Industries include automotive, dental, consumer appliances, and so on. I'm most familiar with jewelry uses so I'll be describing that aspect.
For the wax carver the fragility of a piece of filigree jewelry needs a very tough and somewhat flexible type of wax (but still hard enough to hold detail) both for the original and for the injected wax models if more than one piece is needed. A wax that doesn't break easily when handled during spruing and venting. Basic toughness or ability to resist breaking is required. Toughness is a mix of tensile strength, ductility, shock resistance, and flexibility. At the other end of the spectrum is hardness, in this case the ability to retain details. Hardness and small cross sections are two properties that usually conflict. You can have one but the other will tend to not be met. Items needing hardness may have sharp edges and high surface detail that needs to hold true when handled.

Investment casting has one instance which doesn't need injection wax. If only one final metal part is needed then the properties of the wax that can be used to make the model can be broader, and may have less to do with how flexible the wax object is and more to do with how the wax "Master" whether by hand tools modeling, hand tools carving (or a combination of the two), or by machining which includes lathe turning, vertical milling, or horizontal mill machining.
Investment casting has been used for hundreds of years (it was called by the older name, lost wax casting), and used mostly for the "only one part is needed" method.

Injection wax is a mid-step wax in the investment casting) process when more than 1 part of a carved or constructed wax model is needed in order to make multiple metal castings of the model. You need a mold to make a wax model for every metal part you need to invest and cast. That's where injection wax comes in.
It's used to make multiple wax models from a flexible rubber mold. Vulcanized rubber was mostly used in past times (actually not so long ago). Heat was needed to cure the rubber so a wax master model could not be used with vulcanized rubber. The original model was cast into metal (by a first use of the investment casting process). The resultant metal casting was then used to make a vulcanized rubber mold. Popular these days is a transparent or translucent silicone mold which does not need to be heated so the original wax model can be used (it saves a pretty big step, plus it saves all the work that went into the original wax model should something go wrong with that first metal casting). Each injected wax model is "invested" in a special type of refractory cement called investment plaster, into which the molten metal is forced, so it needs to be able to stand up to the high temperature of the melted metal.
It's more complicated than this, but you can think of the "invest" part as simply having the wax model dipped into investment plaster. A wax cylinder with a cone on the end (called a sprue) is added to the model before encasing it in the plaster investment, completely covering it except for the end of the wax cylinder which serves as a pathway for the molten metal to get into the space where the invested wax model once was. The investment plaster containing the wax model is placed into a wax "burnout" oven which goes slowly up to around 1200 F melting and completely vaporizing the wax model (except for a tiny bit of ash), leaving an empty mold out of the space where the wax Model was.

How do you force molten metal into the space where the wax Model resides? For pieces that are medium to large you can just use gravity. For very small parts like jewelry which has a lot of detail an assist is needed. For many years (and still today) a centrifugal casting machine was/is used. Now there are other techniques adapted from industrial metal casting and used in the production of casting jewelry.
There are many details I'm leaving out here, myriad more techniques and tips (and major innovations; case in point, 3-D printers!).

If you're a beginner, you'll probably want to use the old methods (much cheaper), but you'll still need do spending to get up and running. I'd begin by doing lots of reading from lots of sources (not just one source), and some YouTube watching. Reading is more informative but takes more time than watching a video.
You can also approach it by only doing part of the process. Just be the wax carver who makes the master model, or be the wax carver and the silicone wax maker (or the one who also makes the injected multiple wax models).
Then give whatever you've made to a metal casting business which can also make the rubber mold.

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This may be already widely known, I "discovered" it quite a few years ago but the saying that "there's nothing new under the sun" may apply & other mold makers have discovered it also & shared it on the internet.

But I'll describe it anyway, neither detailed nor briefly. It has a major disadvantage because it takes much more time to make each wax model from the rubber mold. 90% of that extra time is in waiting, not so much in man-hours but it's still a disadvantage. A low melting temperature injection wax helps counter the wait time. I remember I used a low viscosity pink injection but I couldn't tell you the specific brand name. I also don't know if the type of injection wax had anything to do with the success of the process, hopefully not. One other benefit (than the avoidance of all around shrinkage) is you don't have to buy a wax injector. But then to take advantage of not needing a wax injector, you need to already have a high vacuum pump and bell jar (vacuum chamber) of fairly generous size, and not many people have one. If you make a lot of silicone molds you may have one for de-airing the silicone. There is a type of wax injection machine that's been around for years that uses vacuum along with heat to inject the molds, but without the waiting. It exists because it makes perfect wax duplicates. I don't know how much those with the vacuum feature cost.
The DIY vacuum method I came across goes like this: make your solid translucent/transparent silicone (platinum cure) mold, it does require a shrink-free and very heat resistant platinum cure silicone mold (I don't know if anyone still uses the vulcanized rubber for the mold, but you can't use the original wax master because vulcanization takes heat. Cut the mold using the standard techniques and remove the original master model. Go to your local second hand store (if you have one) and get an old, junky, small, but tall electric kettle with detachable cord (mine set me back about 10 bucks). Get some injection wax that's fairly low viscosity when melted. That tends to be ones without too much plastic content. Hopefully your silicone rubber mold just fits into the kettle with a few inches to spare in height and that the kettle fits in your bell jar.
Dust the cut surfaces of your silicone mold with some talc, & blow off any excess. Sandwich the mold between a couple of thin aluminum plates (or some other stiff heat resistant material, glass works if you know how to cut glass). Wrap some natural (not plastic) string around the assembled sandwich to hold it precisely together but not too tightly. Melt your injection wax in the kettle along with the mold sandwich. The Wax level needs to be at least an inch above the top of the mold sandwich. When the wax is short of overheating (don't let it smoke or "burn") but of as low a viscosity as possible, detach the cord, put the kettle into the bell jar, and turn the vacuum pump on. When it hits full vacuum, the wax will bubble if it's hot enough but not bubble enough to overflow the kettle. Cut the vacuum slowly if it overflows, wait a few minutes and turn the vacuum back on. If all is well, let it bubble for a few minutes, cut the vacuum let it go down a bit, then turn it back on. Repeat this a few times. Then let the wax in the kettle cool (with the mold in it). When the wax has turned into a paste, remove the sandwich (with the string you let hanging out of the pot, forgot to mention that). let it cool completely, peel off wax from the outer surfaces and carefully disassemble the sandwich. You should have a perfect duplicate of your original model that's a tiny bit larger than the original, courtesy of the heat which enlarged the silicone mold (or at least that's my theory as to why it's enlarged!).