casting brass query

Re: casting brass query

Bob Hackett(Mainely,Bob)

>Rather than use an airline just use your shopvac in blower mode.

Most of the casting I`ve done I used sand in a 2 part flask to cast.If you do use plaster I`d bake it for awhile to be sure it was absolutely dry.

You can use a cast iron crucible but make sure it has thick walls.That dutch oven is not something I`d want to bet money on.

Mainely,Bob

Re: casting brass query

ThomD

>There are some simple methods here:

http://www.backyardmetalcasting.com/index.html

Beyond a certain point, you will probably want to employ propane, and these burners can be used to make forges, heat treating furnaces, blueing baths, foundries, or kilns:

http://www.hybridburners.com/

http://www.geocities.com/zoellerforge/

http://ronreil.abana.org/design1.shtml

For refractory...

David Barnett

>...depending on what you're casting, Bill, you can either use petrobond (a casting sand and oil mixture), or if you're doing lost wax, I'd suggest using a mix of 50/50 US Gypsum Hydrocal with 200 mesh silica (flint from ceramic suppliers) - sinmple PoP is only adequate for lead, some white metals, and pewters. Both are easily found and will do the trick, although depending on the size and design, it may be wise to add shredded glass fiber, as well. As for a firing schedule, I'll be glad to give you more details if you like. The important thing is to get rid of the physically bound water, then the chemically bound, then finally any organics (wax, etc.,) at about 1000F. You can do this in one operation (progressive burnout) or in two. You have to be careful with any zinc-bearing alloy, such as brass, as vaporized zinc is severaly debilitating to the nervous system. Bronze casting ingots or shot may serve you better, but it's your call. I rarely do base metal these days -- mostly PDV (pate de verre - glass frit/powder casting -- but now and then I alloy 22k gold into ingots. I recycle my silver, too.

Electric kiln? Gas kiln? Gas or charcoal foundry furnace? Definately consult BackYardMetalCasting as ThomD suggests. Great resource.

Re: casting brass query

Todd Hughes

>I have melted small amounts of brass in an iron laddle in an old hand crank coal forge more then a few times. This was used to pour brass inlays in iron.Worked good. Have melted larger amounts of brass in clay or graphite cruciables and again used a hand crank coal forge.In this case the forge was smaller then mine and we did build an encloser with fire bricks around the cruciable to make it easier. I can't answear your question about the plaster of paris mold for sure but I would think brass would be to hot but anm guessing now.We did sand casting with wooden patterns. I made a spoke shave using an old factory one for my pattern, came out nice. ....Todd

Re: casting brass query

Ernie Miller

>I have found that a hair drier works good for the blower moter as they have three speeds so you can adjust the air flow better. I have only heat treated blades but the hair drier works great.

Re: Bronze?

ThomD

>Anyone melted bronze, any particular difficulties?

Brass is easily machined with stuff like woodturning lathes, depending on the use you have in mind.

Re: Bronze? *LINK*

David Barnett

>Statuary bronze is straightforward and easy to melt and cast. For smallish amounts, tools and art objects cast one at a time, you can manage with a melting torch. For jewelry-sized castings; knobs, pulls, block plane parts, whatever, you can even get by with a large air/fuel torch. I've cast both Rio Grande's "Ancient Bronze Casting Grain" and "Caster's White Bronze Chunks" with really rewarding results. Again, for investment, I'd use 50/50 PoP (such as Hydrocal, Statuary Plaster #1, or Pottery Plaster #1), and 200 mesh silica. However, if you only need small amounts, try a local dental lab or jeweler supply and buy premixed investment in little 1kg bags or 2kg canisters (Kerr SatinCast 20 is about 10USD for 2kg). Most of these dental investment mixes work very nicely for 2000F castings (white bronze's flow point is 1850F, caster's brass flows at 1900F, and manganese bronze needs 2100F). If you're sand casting, ask a local founder for a couple buckets of used Petrobond.

As for iron ladles, they'll work, but I'd recommend a clay/silica crucible in one of those handles with the wing nut. The crucibles are a few bucks each, the handle costs 5 or 6 dollars. This way you can keep separate crucibles for each alloy. These should be prepped with flux (borax is fine) before first use.


Rio Grande

thanks to all for helpful advice

bill tindall

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