brass casting advice?

[caliber45]

Gents -- I'm considering trying to sand-cast my own brass triggerguards and buttplates. A few questions: 1. Can I use my oxy-acetylene rig as the heat source for that amount of brass (one item at a time)? 2. I'll be using cartridge brass; do I need to remove spent primers first? 3. For longer items (triggerguard), is it best to cast vertically (long-ways) or horizontally? 4. If horizontally, should I use two sprue-holes vs. one (it appears the sand-cast commercial triggerguards I buy are cast via the two "pin-tabs"). 5. If using two sprue holes, how quickly must the casting be done to preclude one half solidifying before the second can be poured? 6. If oxy-acetylene is useable as a heat source, is there a danger of overheating ("burning") brass (causing alloy "separation")? 7. Is casting sand preferable to delft clay or a mixture of the two? 8. If a mixture, what proportions? 9. What is a good crucible size for that amount of metal? 10. Can you recommend a good source for "hobby" amounts of sand/crucibles ("local" or online)? 11. Is there a tutorial available (this website or other?) on sand-casting such things? I'm welding up proper-sized flasks. Any advice will be much appreciated! Thanks. -- paulallen, greencastle, IN

[Glenn]

I've had the same questions about brass casting for a long, long time.  Can't wait to see all the responses and advice.   

[AndyThomas]

Gents -- I'm considering trying to sand-cast my own brass triggerguards and buttplates. A few questions: 1. Can I use my oxy-acetylene rig as the heat source for that amount of brass (one item at a time)? A charcoal forge barely makes enough heat. 2. I'll be using cartridge brass; do I need to remove spent primers first? We don't.3. For longer items (triggerguard), is it best to cast vertically (long-ways) or horizontally? We do them horizontally.4. If horizontally, should I use two sprue-holes vs. one (it appears the sand-cast commercial triggerguards I buy are cast via the two "pin-tabs"). We use only one. 5. If using two sprue holes, how quickly must the casting be done to preclude one half solidifying before the second can be poured? If the brass is hot enough, it will actually fill both sprue holes while pouring into only one!6. If oxy-acetylene is useable as a heat source, is there a danger of overheating ("burning") brass (causing alloy "separation")? Some of the zinc will boil off if it's hot enough. But's that's OK.7. Is casting sand preferable to delft clay or a mixture of the two? 8. If a mixture, what proportions? We buy our "green sand" premixed, though we're constantly adding clay (bentonite)to it.9. What is a good crucible size for that amount of metal? We use a #4, which is plenty big enough.10. Can you recommend a good source for "hobby" amounts of sand/crucibles ("local" or online)? See below.11. Is there a tutorial available (this website or other?) on sand-casting such things? See below.I'm welding up proper-sized flasks. Any advice will be much appreciated! Thanks. -- paulallen, greencastle, IN

We get our green sand (and additional bentonite) from these guys: http://foundry101.com/search.htm

We get our graphite crucibles from these guys: http://www.lmine.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=LMS&Category_Code=prem_graphite

You can find more info about how we do it in both the Martin's Station rifle albums and also the two casting albums, here ;  http://s498.photobucket.com/albums/rr347/FlintlockAndy/

The casting video here is excellent: http://americanpioneervideo.com/Titles%20and%20Prices.pdf

This video is also great: http://www.williamsburgmarketplace.com/webapp/wcs/stores/servlet/ProductView?storeId=10001&jspStoreDir=wmarket&categoryId=25873&catalogId=12120&langId=-1

Our method is a combination of the two videos.

This is a good book: http://www.amazon.com/COMPLETE-HANDBOOK-Paperback-Complete-01-Mar-1979/dp/B004JBZG50/ref=sr_1_10?ie=UTF8&qid=1333065974&sr=8-10

Green Sand is a problem for hobby sandcasters. Both the clay and water get used up during the pours, so you have to add more of one or both every time. REAL sandcasters can feel the sand and tell if the proportions of sand, clay, and water are right. This "feel" only comes with experience. Pretend sandcasters, like myself, make up for knowledge with good files.  You might want to take EK's advice and use Petrobond instead of green sand. If it had been available in 1775, we would be using it at Martin's Station.

Hope this helps,
Andy

[Bill of the 45th]

The only thing I can add is Yes, you need to deprive the cases.

Bill

[docone]

Well, a lot of those primers are brass. If they are steel, they won't mix in the melt.
Another point.
Foundry disease. I have tried melting brass with a torch, and in my Kerr Electromelt. In both cases, the zinc has boiled and fumes exited. Both my wife and myself got a good whiff, and had those flu like symptoms for a couple of days. It is not like melting silver or gold.
No matter what you do, make sure there is ventilation. Not so much you cannot melt, but enough that you are upwind of the zinc fumes. My wife and myself are experienced casters, and it got us.
Good luck with the project. I know I really enjoy the satisfaction of the melt to finished product. A lot of work, but to me, it is definately worth it.
I have yet to try lost foam casting.
That is next, down the road.
Good luck.

[Captchee]

   i  purchased my foundry from foundry 101 as well . the standard kit will give you the basics for casting TG 's and butt plates .
 you will have to make your own patterns though .
 With TG I cast them  on their sides . Your  form will be  two pieces  a right and left side .
 The two sides must match  when placed together .
   One side is set in  the cope the other side  is set  in the drag .
 Once the sand is packed , the forms get removed . Your reservoir is  cut into the sand  in the cope . The vent and pour hole is set to match  the location  of the reservoir in the drag .
as to  the lugs you see on the TG's you purchase . These aren’t pour spurs. They are flow spru’s .
 They are connected to the reservoir .
As such once you have your reservoir set in the sand , you  connect that to  your actual part     by flow spru’s   . until you get things down  its best to have more flow spru’s . this insures that the part gets completely  filled . You also can add more vents  which also helps tell you that the part has completely filled .
 What the reservoir does is  keep the  melt liquid for a longer time  and thus helps  ensure you get a completely filled part .

  Ill have to look around and  see if I still have all the photos of my casting  set up .
 But at one time Foundry 101 had a tutorial on  sand casting .

As to your brass . Yes you need to remove the spent primers .
As to using a torch to do your melt.
 Trying to do it that way  can result in you burning out the zink in the brass rather quickly  especially if your holding the  torch right to the brass. “YOU DON’T WANT TO BREATH THOSE GAS’S IN “
 This can also happen with a foundry . It takes time to learn to read the  brass . As such  you can add more zink by simply adding a few pennies to the  melt  so as to keep your zink content up .

 Remember also  that you need more brass then you think  as  you have to fill the reservoir and the vents .
 This brass doesn’t get wasted . You simply melt it back down and pour it into ingots  or just save it for your next  castings .

Lost Foam casting is alittle different . For that you don’t need  a cope and drag .
 In simple terms , you make you part from  blue foam . The foam is then settled into the lose  dry sand  by either poring the sand around the part  and settling the form  OR  by means of settling the part in  aerated sand ..  From there you add your  pour hole and vent down to the parts .
A type of reservoir is still used on top of the sand . Again this helps keep the pour hot as well as apply pressure .
When the melt hit’s the foam , the foam is vaporized  and replaced by the  melt . Once cooled , you have your part

[David Rase]

Here is a source for brass, crucibles and anything else necessary for casting brass.  I have purchased from them several times.  They specialize in small time backyard foundry.
Dave
http://www.budgetcastingsupply.com/

[Eric Kettenburg]

I don;t see a torch being able to melt the requisite quantity of brass.

I used a charcoal forge for years.  Worked perfectly but used a LOT of charcoal.  It's not like coal i.e. forge like a shallow dish w/ coal heaped up, you need deep "pot" to the forge, mine was @ 12" diameter and 12" deep with the flue from the crank blower coming in at the bottom on the side.  You nestle the crucible down inside the 'pot' sitting on a firebrick or two so it can't sink out of sight, and you keep shoving charcoal down around it with tongs as well as over it (you need a lid on the crucible).  Borax works fine for flux.  Green fumes baaaaaaaaad.

Petrobond is particularly useful in a situation where your forge is in an unheated structure, as the greensand will freeze in the winter (between uses obviously) but the petrobond will not.

That blue foam technique sounds pretty cool, never tried that!

[caliber45]

Wow! As expected, a wealth of useful information. Thanks so much, guys. Great advice, and very welcome! Now I've got a batch of "homework" to do. Wish me luck. If I can make it work, will try to learn to post some images. Thanks again! -- paulallen, greencastle, IN

[rich pierce]

It all sounds complicated and scary to me and I'd want some hands-on lessons!

[James]

I just want to say thank you to caliber45 for starting this thread and to those who provided info. From another wanting to try this, thanks Jim

[Eric Kettenburg]

Rich - it does seem a little scary, mostly in a hypothetical sense.  In reality, the only time I've been a little 'nervous' is the period where you are lifting this near-white hot crucible out of a forge w/ a pair of tongs and moving it over to the flask for pouring.  After the pour and you stick the crucible back in the forge to cool (slowly) or to recharge it, there's always a "whew!" moment.  However, this probably comes from working alone in less than optimum conditions and with no proper safety equipment.

The real cautions are (1) make sure to wear some face protection and preferably some leather chaps and gloves, and (2) make sure that the area in which you are working is DRY i.e. no wet or muddy dirt floors etc.  If you have a spill and some molten brass hits an excess of moisture, there's going to be some crazy splatter.

Also go with LONG handled tongs.

[Dphariss]

Our Guild is hoping to do some casting this summer.
With professional assistance.

Dan

[Captchee]

It all sounds complicated and scary to me and I'd want some hands-on lessons!

 like Eric stated . at first its a little intimidating. Frankly it should always be .
 The reality is that depending on  what your melt is , the temperatures can be well over 2000 deg .
 You get an splatter on you and it will burn all the way to the bone  near instantly .
 
 I ALLWAYS wear leather boots,  a  leather apron , full leather insulated welding gloves  a face shield and hat when I get ready to pour  or am checking the melt
.
 A few years back I had just finished a pour of Brass . Turned to pour the remainder into  my lee ingot mould. And POP!!!. A small splatter came up and hit my face shield , leaving a 21/2 inch burn across it ..  Without the shield , it would have hit my nose and left eye  .
   Casting is one of those things one would do well to be VERY respectful of at all times   one you start your melt
 Past all  that . The first time you  see the crucible glowing  near white hot  and t hat  inside that is liquid. Its really awe inspiring . The feeling is just un explainable .
 Then when you  finally achieve your first  actual usable casting . Well now that’s  something all in itself .

[Glenn]

To all you with experience that have provided your advice; THANKS for you generous contributions.   

I appreciate mostly the cautions, as I have held off doing this becuase I dont quite know the safety factors I need to use to accomplish all this safely.

Great thread you started caliber45.

[Glenn]

Does all this apply the same to casting lead and German silver, or are they totally different critters altogether?

[Captchee]

Does all this apply the same to casting lead and German silver, or are they totally different critters altogether?

 Im not sure im following your question Glenn .
Can you cast  a  trigger guard of lead ?
The answer would be yes . You can use the very same sand molding process  that you would use for brass , sterling or German silver .
 But that’s where the comparison stops
  Both the melt point and liquid flow points of GS are 3X what lead is .
 The flow properties are also different
 The gasses produced  are also way different .
See each  material is different enough that  its often best to start simple and work up .
Aluminum IMO is a very good  material to start to learn casting with   in that it has a relatively low melt and flow point . Once at flow temperature it also flows easily.
 Brass on the other hand  has a flow that’s alittle thicker  . Thus it often “depending on the alloy “ doesn’t like to flow into thin areas . So your moulds need to be thicker  then what  can be achieved with aluminum.
 What im getting at with this is that every time you start to cast a new alloy , it takes some  learning .
 Not only about the melt characteristics , but also about the alloy characteristics in order for a person to achieve a good casting  SAFLY