What exactly are these? I see this term quite a bit in reference to detail parts. Are these NOS parts or a casting technique? Are these still made?[%-)]
Just Google " LOST WAX CASTING " and you will get tons of answers and videos explaining the whole process.
I asked my metal shop teacher about that years ago.
He said the casting is fashioned from wax, packed in sand, and the metal poured in. The wax was “lost” in the process.
It is a mold making technique that uses a wax master to make the mold. It is also sometimes refered to as investment casting. As said earlier, a wax master is used to make a sand or plaster mold. The wax is then burned out of the mold leaving the cavity that is then filled with the material used to make the finished part, usually a metal of some sort. Once the part is cured or cooled the mold (investment) is broken away and the part is removed.
Dan Pikulski
Investment casting isn’t limited to small parts. One of the, “Popular Information,” channels had a show about a centuries-old technique for casting a full-size brass cannon using the same methods jewelers use to investment-cast filigree earring pendants.
Chuck (modeling Central Japan in September, 1964)
Thanks![:)] I guess that answers the question if these are still being produced.[tup]
Is the mold still re-usable? or does the mold have to be rebuilt/refinished?
Depends on the mold.
I have a friend that is a jeweler, and makes custom jewelry. I’ve been trying to get him to carve some waxes for model railroad parts, people, etc. He got out of model railroading several years ago, and hasn’t been real enthusiastic about the project lately.
Rotor
Most of the time the mold is broken to get the part out. Once the original master is made, a different mold process, like an RTV two part mold, is used to make many wax parts. These wax parts are then used to make plaster or sand molds so the metal can be cast.
Of course the next question will be…why not use the RTV mold to make the part? The parts from a RTV mold will usually have a parting line to be able to get it out. This is why wax is used to make the master. It can be cleaned up before the plaster/sand mold is cast around it.
One of the smallest cast parts I have ever seen is a bell for a Z scale engine and the largest was a 16 cylinder engine block for a gas compressor that stood about 12’ tall. The master to make the compressor mold was a wooden part and the mold did have to be made in sections. It was pretty cool to see the engine block rendered maple.
How ironic! How It’s Made is doing a segment on how to make lost wax castings right now!
Yes, lost wax castings are still being made. Check Walthers catalogue. The silicone mold used to make the wax pattern can’t stand the heat of the brass casting material.
Pretty much all the metal detail parts, brass and white metal, are lost wax castings, (except of course etched metal parts). Details West, Cal-Scale, Custom Finishing, Precision Scale, Overland (just discontinued) are just a few of the companies that produce them currently.