casting brass

[glycerine]

You guys who CAST your own parts... what metals are you using? At what temp does brass melt? Do you cast with sand or the lost wax method?
I'm wondering if there's a way that I can make my own components without a metal lathe. I was thinking cast in brass and send them off or find a local jeweler/plating shop to be plated.
Can anyone offer me advice/suggestions?

 

[NewLondon88]

I can only kick in a tiny bit of info, since I haven't cast my own.
But in investigating getting components made, I was told that
a lot of the parts should be stamped and plated, and any casting
would probably work best using lost wax or investment casting.
Getting the original made is the first step, and most of that could
be done on a metal lathe for control. If you don't have access, then
you might find someone who can do it for you. There are people who
can take your CAD files and create the pieces on CNC machines.

If there is to be any engraving
on it, you may want to work in wax instead of metal to make your
original. Jeweler's wax is hard enough to hold up on the metal lathe,
and it takes detail very well. You can turn your components and then
take it to a jeweler with your design and have them carve it for you if
you don't do carving. Then the wax can be used for lost wax casting.
That will get you your first master and mold.

If you want to try some of the wax, let me know. I think I have some left.

 

[mredburn]

The wax used in carving is usally File-a -wax (brand name). You can shape it with burs or files or scrapers. YOu can turn it on a lathe. the firmer the grade the better. You can take the model you create to a local jeweler who can cast it for you, then a rubber mold is made of the master so you can reproduce the piece over and over. The problem with mold reproduction is the mold has a shrinkage factor unless you have a 100% poured silicone mold made. YOu can cast brass that you have on hand but sometimes you get brittle metals when done this way. Brass melts at 1750 degrees for 70/30 YOu can also get a brass product called jewelers brass that looks like 14k when polished, its used to make display models of settings without the cost of doing them in gold. Im making most of my masters in brass turned on the lathe and then molded andthen cast in sterling silver. If your piece is something that can be turned on the lathe buy round brass rod and make the pieces one at a time. if they are more of a freeform and dont lend themselves to turning, such as clips. Frabrication by soldering filing grinding may be an option. If you have a design you need help with send me a pm. there are pictures of some of my parts are under the threading wood post that was done just a day or so ago.

 

[glycerine]

Is it expensive to have a jeweler make a mold? And how much does sterling silver cost?

 

[ldb2000]

Todays spot silver price is $16.99 per oz . Call these people for prices and what info is needed , http://www.billanticasting.com/BillantiCasting/Home.html

 

[mredburn]

Depending on your area molds can range from 15 dollars and up. If it gets to be more than that let me know I might be able to help. Sterling Silver casting grain is running between 18.00 an ounce and 20.00 an ounce for the tarnish resistance stuff. The low tarnish has different trade names. Rio grande supply, Thunderbird supply, sell sheet, tubes casting grain, etc. They will sell directly on line. I buy directly from a refinery but there isnt that much difference in price. I buy sheet and tube from thunderbird Kitco.com home page displays current metal prices.

One of the factors in making a mold is shrinkage. differnt mold rubbers have differnt shrink rates. If you make a master to have cast and then molded you will have to guess at how much shrinkage you might get. any where from 2.6% to .065 % for silicon rubber and o % shrinkage on room temp poured silicone 2 part types. However the lessor shrinking materials cost more. not every one carries the 2 part rtv silicone mold material. Most jewelers dont have to deal with the tolerances required by pen parts. The alternative is to make every thing over sized and turn it to finish specs after the casting. Clips are different. the shrinkage is not as much as a problem trying to match a turned blank. There are at times as much luck and magic as science in casting.

www.thunderbirdsupply.com

www.riogrande.com

www.kitco.com

 

[glycerine]

So you're saying the mold itself can shrink? And the metal parts cast from the mold should be consistent or they too will vary in size because of the mold shrinkage? Would it be better to do tubeless pens when having parts cast? Or at least wait until the parts are made and then find the right tube size?

 

[BRobbins629]

You can use cast parts with tubes, but it generally isn't necessary. The main reason for tubes is to have something to press the fittings into.

I do my sterling silver casts from wax using the lost wax casting process. Now I do the wax models either by hand carving, turning on the lathe, CNC or a combination of them. Although I have cast myself, I have found it easier and less expensive to have someone like Cranston Casting to do them. If you are not making many of the same thing, you do not need a mold. There is some shrinkage but that is generally easy to deal with. You can trim the metal to meet the pen parts or trim the pen parts to meet the metal. Either way works.

I find that the silver in each part is only a few dollars. You can probably do it in brass, but the finished cost will not be much less particularly if you are having them plated. The labor to cast them is generally more, depends on the complexity and how many you are making at one time. The labor just to have it cast can range from $5 to 12 each for typical pen parts such as clips and centerbands.

Jeweler's wax is very easy to turn and carve and inexpensive. I would recommend getting some cylinders and flat pieces and start playing around. For CBs, any lathe tools will work fine,. You will need some wax files and jewelers saw, a small xacto knife and some carving tools such as dentists use to pick at your teeth for the flat pieces. What doesn't look good doesn't need to be cast. When you have about 8-10 pieces, you can reach a minimum casting order quantity. If one comes out really good, you need to finish and polish it, but you can then use that to make a mold for future production quantities.

Realize too that a piece directly out of a cast is not ready to be put on a pen. Whether from a mold or original, it is full of firescale and has a sprue attachment that needs removal. You will need some jewelry skills and equipment for filing, polishing, maybe tumbling and perhaps soldering if the piece requires assembly as some clips might. You may also need to heat treat the pieces to get them springy but this depends on the thickness and how much heating you need to do (such as soldering) after casting.

We can guide you through the process, but my best recommendation would be to try to take a general jewelry making class and a class in lost wax casting or wax carving if they have one in your area. It helped me tremendously.

 

[bitshird]

If you are thinking about casting in brass your self, it requires good ventilation, between the fumes fro the flux, and the gas released by the silicon alloys it can be quite hazardous, even Sterling in the more exotic alloys with Indium boron and smaller percentages of copper can be bad for your lungs, the Good old Sterling .925 Fine silver and .075 pure copper needed decent ventilation, since you fluxes were either Boric Acid or Borax or a PH Neutral mix of the two, the melting temp for a good flowing Silicon Bronze, or Herculoy is around 1850 tom 1900, I have to look it up. since it varied by alloy, the anti tarnish sterling's also run higher temps than traditional Sterling, and yes,As long as the alloy contains .925 fine silver, you can use what ever you wish as the other .075 % and still call it Sterling.
A strange alloy Argentium is pretty proprietary as far as flux materials and how much can be used to recast. and it has less tinsel strength and resistance to deforming.

 

[glycerine]

Where would I take those type of classes?
So it sounds like if I had a metal lathe, the "easiest" way to go about this would be to turn my parts from brass and have them plated. I'd like to get to the point where I can create just about anything I or a client could come up with...

You can use cast parts with tubes, but it generally isn't necessary. The main reason for tubes is to have something to press the fittings into.

I do my sterling silver casts from wax using the lost wax casting process. Now I do the wax models either by hand carving, turning on the lathe, CNC or a combination of them. Although I have cast myself, I have found it easier and less expensive to have someone like Cranston Casting to do them. If you are not making many of the same thing, you do not need a mold. There is some shrinkage but that is generally easy to deal with. You can trim the metal to meet the pen parts or trim the pen parts to meet the metal. Either way works.

I find that the silver in each part is only a few dollars. You can probably do it in brass, but the finished cost will not be much less particularly if you are having them plated. The labor to cast them is generally more, depends on the complexity and how many you are making at one time. The labor just to have it cast can range from $5 to 12 each for typical pen parts such as clips and centerbands.

Jeweler's wax is very easy to turn and carve and inexpensive. I would recommend getting some cylinders and flat pieces and start playing around. For CBs, any lathe tools will work fine,. You will need some wax files and jewelers saw, a small xacto knife and some carving tools such as dentists use to pick at your teeth for the flat pieces. What doesn't look good doesn't need to be cast. When you have about 8-10 pieces, you can reach a minimum casting order quantity. If one comes out really good, you need to finish and polish it, but you can then use that to make a mold for future production quantities.

Realize too that a piece directly out of a cast is not ready to be put on a pen. Whether from a mold or original, it is full of firescale and has a sprue attachment that needs removal. You will need some jewelry skills and equipment for filing, polishing, maybe tumbling and perhaps soldering if the piece requires assembly as some clips might. You may also need to heat treat the pieces to get them springy but this depends on the thickness and how much heating you need to do (such as soldering) after casting.

We can guide you through the process, but my best recommendation would be to try to take a general jewelry making class and a class in lost wax casting or wax carving if they have one in your area. It helped me tremendously.

 

[mredburn]

Our loacal college has classes as does the art center. There are jewelry schools around the country you may have to google them to see if there is one near you. The jewelry schools vary. SOme have short classes for specific skills some have year long classes. Our local callege and art center teach jewelry design as basic jewelers skills. Wax carving, casting, soldering. how to saw etc. they do not teach repair classes.

The molds shrink after they are vulcanized but they remain constant after that. If you design a nib for example that fits a 7mm tube. if you make the master to just fit in the tube the mold of that piece will have enough shrinkage that the pieces made from the waxes of that mold will be sloppy in the tubes. I tend to oversize those parts and then turn them down to fit. IF your going to make parts and plate them you may want to check into plating your own. YOu would need a rectifier for power and the chemicals for plating, misc anodes and stainless steel pans. THe is a company locally that manufactures and sells what you need..www.dalmarplating.com
this is different from the traditional plating solutions check out his website. A lot of what you do depends on lacaly availeble services and the amount of pieces you will make.

 

[glycerine]

Ok, thanks again.

 

[workinforwood]

I would purchase a metal lathe,Beer and a Pizza. Then I would invite Bruce over for some Pizza and Beer and while he was washing down his pizza, I would introduce him to this new lathe and start talking to him about it and the next thing you know, he'll be giving you a free crash course in metal turning! He's not that smart..he'll fall for it, trust me!:monkey::biggrin:

But..seriously, a metal lathe is going to be the way to go. If you could cast your own brass, it's going to cost you money to get a kiln that hot, Brass itself is not that cheap to buy, the waxes and or molds are money, the plating is money, there's the safety issues, the fact that you need to learn about melting metals and removing the skag I think it's called..and in learning all this new stuff you are going to be wasting all these expensive materials. You can purchase a good size metal lathe and enough tooling to get you going for $1200 easy. That's not that much money, and you can go cheaper, but if you go too cheap and small you could be spending your money twice, so I say go as big as you can afford. If you turn parts from brass, you don't have to plate them either. You can, but you also can just let them be brass. Plating wears eventually no matter what, but the brass itself will wear very little, mostly just tarnish which can be cleaned off. Bruce is in VA, and he's a very smart generous person that if I were in your shoes I would be leaning on his shoulders. I just went through similar issues myself and sweet talk the Capt to come to my rescue. A couple hour crash course is all you need to get started.

 

[titan2]

I would purchase a metal lathe,Beer and a Pizza. Then I would invite Bruce over for some Pizza and Beer and while he was washing down his pizza, I would introduce him to this new lathe and start talking to him about it and the next thing you know, he'll be giving you a free crash course in metal turning! He's not that smart..he'll fall for it, trust me!:monkey::biggrin:

But..seriously, a metal lathe is going to be the way to go. If you could cast your own brass, it's going to cost you money to get a kiln that hot, Brass itself is not that cheap to buy, the waxes and or molds are money, the plating is money, there's the safety issues, the fact that you need to learn about melting metals and removing the skag I think it's called..and in learning all this new stuff you are going to be wasting all these expensive materials. You can purchase a good size metal lathe and enough tooling to get you going for $1200 easy. That's not that much money, and you can go cheaper, but if you go too cheap and small you could be spending your money twice, so I say go as big as you can afford. If you turn parts from brass, you don't have to plate them either. You can, but you also can just let them be brass. Plating wears eventually no matter what, but the brass itself will wear very little, mostly just tarnish which can be cleaned off. Bruce is in VA, and he's a very smart generous person that if I were in your shoes I would be leaning on his shoulders. I just went through similar issues myself and sweet talk the Capt to come to my rescue. A couple hour crash course is all you need to get started.

Now........if I could just find myself someone like that out here in Sacramento........I'd be set with my metal lathe!!!


Barney