how to prepare sand cast brass?

[uplandhunter]

is anyone up for creating a how to on the subject? it would be great to see and learn from. thanks!

[Acer Saccharum]

Search the archives. There was a discussion about this in the last year. I think Taylor may have offered opinion on this subject, as he often does. 

Sand is $#*! on files, but there is little you can do but file the buggers down. Once the sand is gone, use a nice sharp brass only file. Don't use it for steel or iron, just brass.

ALways, always, watch the form that you're filing. Keep your eye on the final shape you want. It's so easy to file too much metal off in the wrong places. Oi, I've been there.

Progress to finer files, then to abrasives mounted on flat sticks. You can scrape the brass at this point. Then polish with steel wood or keep going with finer and finer sandpaper. It's a real pain in the axe. It's one of the more heinous jobs on the longrifle, other than inletting the entry pipe.

Tom

[uplandhunter]

that is still not a how to. I am a visual learner so I was just trying to get a member to put one togather. I have already done the search, but thanks!

[Captchee]

is anyone up for creating a how to on the subject? it would be great to see and learn from. thanks!

are you asking about the whole process of sand casting or just the  after  the castings come out ?
 If its just  preparing the casting to work on , that depends on the quality of the casting  your using .
 With a quality casting , a  good  brushing , then rinse  in running water   followed by  block sanding , will yield you a part that is ready for polishing .
 You will need to cut off sprus  and file down those areas  but  that’s about it.
so unless your asking about the whole casting process . there really isnt a whole lot to write a tutorial on 

Acer ,,
Maybe in miss understanding you  but , why do you have sand in your castings ?
. while its true that a little sand will stick to the casting  initially
  It brush will off . The exception is   if during the set up  the reservoir and  or gates  have not been properly prepped.  Thus sand can be pulled into the part  with the flow .
 Now I don’t know for sure but I suspect that  the poor quality of a lot of the sand cast parts we see today is due to  multiple  pours   from the same mould .   In doing so , with each pour , you get reduced detail  and more of the rough pitted surface to the part .  In which case you do have sand  with the scale .
  But even this can many times just be knocked of with sanding paper . Then followed up with  file work if needed .

[Jim Kibler]

Not sure I exactly understand what you're saying Captchee, but I can't imagine ANY sand casting being good enough to not require filing.  Heck, I even file investment castings.  I don't see how good clean crisp work can be acheived otherwise.  After filing, abrasive paper or stones can be used to bring the surfaces down to a finer finish.  Using fine files will help minimize the amout of this work.  With regard to multiple pours from the same mold, I have never heard of such a thing with any sand casting process, even no bake binder processes.  It seems all of the sand castings produced for the muzzleloading market are cast in green sand.  When the part is poured, the mold is useless for further casting.

[JTR]

Some of the sand castings I have look like they were cast in gravel!

I think the original poster is looking for a step by step tutorial on sand casting.

John

[Captchee]

Jim
 The only time the mould is useless is if one over pours  IE the pop   and pour holes are fill to the point they over flow.
 Once the castings cool  they will reduce slightly  allowing the  entire casting to be lifted out of the sand with little damage . I have gotten as many as 4 pours from the same sand moulds . Granted though with each pour you lose detail

 the key is the proper sand .  real find green sand can produce detail  fine enough to actually leave a finger print in the casting
 here is a quick casting  to show you
 top row left  Aluminum right from the sand . #2 is  hit with sand paper and  polished #3 is  a 2nd casting from the same  mould  as 1 and 2  . Note the file marks needed to remove the  rough finish . #4 is the   master

 bottom row
all are 1 off castings IE id did not try and re cast from the  same mould .
Note that these do not have the   rough finish of the Above # 3 .
 also if you look close, you can actually see the  grain of the wood from the masters showing in the casting .

TG ,  Buttplates and the such , should come out just as clean .  However what is purchased  most times isn’t . the only way I have seen to reproduce such  pieces is
a) to re used or get multiple pours
b) use a course sand to start with
c) use  fine sand with little to no binder other then water .



 i also know a fella who locally cast Bells . . while i have not seen him mix his sand personally , he has told me that he uses  sugar as a binder . But again I don’t know this for sure .
 i know he must be using something different because  i have inspected his  cope and drags after casting and can tell you the mould area is very hard and burned  dark grey black color  . to the point  it feels like one could  actually  brush the sand away and have a shell .
 seriously its so hard that  he separates it  from the usable sand  so as  to re crush  and sift prior to  putting the sand back into the box

[D. Taylor Sapergia]

All sand castings that I have purchased were cast in black sand, as far as I can tell.  They are cast much larger (more brass) than is desirable in a finished butt plate or trigger guard, and are very rough.  Often, the joint is a-scqueue, but there's so much thickness, they dress down easily...just need to spend the time, and know what you want to end up with before you start.

[Randall Steffy]

Clarification of the term "green sand" may be beneficial to this thread. "Green sand " can be any color, the term a label for loose, damp molding sand as opposed to some hard molding system. From Wiki we read, "These expendable molds are made of wet sands that are used to make the mold's shape. The name comes from the fact that wet sands are used in the molding process. Green sand is not green in color, but "green" in the sense that it is used in a wet state (akin to green wood). Unlike the name suggests, "green sand" is not a type of sand on its own, but is rather a mixture of..."

Commercial/industrial greensand foundries never reuse a mold, but then most "nevers" fails sometime. They reuse the sand after reconditioning to get the best casting finish possible. That finish is the result of a merging of many factors, sand coarseness, other ingredients in the sand mix, metal pour temperature, force of the pour, gating design, and more.

Sand cast parts out there vary from heavy (much excess metal) to thinner than original. File that thin casting minimally, due to the fact that they already shrank 3/16 in. per foot to as high as 5/16" per foot from the antique original master, leaving you quite thin to start. The master from some of those copies from original hardware were built up carefully to allow more clean-up and an end product close to original dimensions. Reaves has such castings.

[Captchee]

 sorry for the spelling  guys .  i cleaned it up so i hope its now readable .  Yesterday was a very long day and I just did not take the time I should have with my posts . I apologize for that .
 I would somewhat agree  D. Taylor that alot of the castings today are done over sized . But  one never knows  for sure . This and the quality of castings  I was finding myself getting , was one of the reasons I started casting my own  parts . Well that and availability of  the parts I wanted  or needed .. The final straw was when I ordered a  Sterling  TG and when it came , it was so pitted and warped that it was imo un usable .
  Im sure there are others here like myself who remember when sand casting were about all one could buy . I don’t know about the rest of you but  I remember  the quality being a whole lot better then what we are seeing today .


 I by no means know it all when it comes to casting  in sand .
 As such im sure that there are many different types of sand mix’s that folks maybe using . Ill accept that . But again  I submit that if your getting sand cast parts that still have sand  or glass cinders embedded in them  , it doesn’t speak well for the quality .
But if that’s the case and you are having to use files  to clean up the castings , then  I would agree that the sand would not be good on your files . Thus one should take care .
Again though I use sanding blocks to clean up castings . When I do have to use  files , its only after all the scale has been removed . Thus there should be no sand  left  to worry on  unless  an inclusion is ran into , which can happen
 You folks be safe and have a good day

[Jim Kibler]

Just a couple final points...  The files are used to define shapes, moldings, flats etc.  So on ANY quality sand casting I feel filing is a requirement to producing clean work.  Sanding will not produce the same results.  In the case of re-using molds, the problem lies in the fact that the binder system gets burnt out of the mold from the previoius pour.   Other basic problems with this idea such as a standard tapered down sprue etc, make this impossible besides.   I'll agree that this is never done on a commercial scale and doesn't need to be considered.   I also agree that the quality of sand castings available is sometimes pretty poor. 

[Captchee]

 Yes Randall you are correct about green sand . It can be any color . That color will darken with use .
 But its also not just wet sand .  Green sand has some type of binder added to it other then moisture .
As to what manufactures use  for sand . The sand used to make engine blocks , is not the same  sand as used to make  say jewelry . There simply is no need for the sand to be that fine

 Jim Do you think im just making things up here ?
Seriously  I just showed you a double casting .
 Binders as I said above , can be a lot of different things . I use Fullers earth  and it does not break down  in the sand . It will hold its form  after the  part cools .  If I don’t over pour , I can remove the  part and  get a 2nd  casting . Again as I said before . I have gotten as many as 4 castings from the same mould . It all depends on the part  and the detail
 if your losing you binder  then your either using water or horse pooo
and why are you using a tapered down spru  or gate ?
 have you seen that on any  of the  piece you by from say ToW ? no
 the gates are square .
  your form should also be 2 halves. Cope and drag .
 The bottom half will lift off the poured part   leaving the part , the reservoir  the pour  spout and the pop spout in the top of the  mould . Once the part cools and shrinks . unless you have over filled the mould and thus have  castings spread out around the top of those holes  . All of this will simply lift out of the top half..

 But I guess again , im making this all up

[Jim Kibler]

Captachee,

Your original suggestion as to why commercially available castings are excessively rough or poor quality was that molds could be being re-used.  I have simply said the following:

Sand castings made for the muzzleloading industry are cast in green sand.

Green sand molds are not re-used in an industrial setting.

This is because the binder system is compromised from the heat of the previous pour.

Further, typical mold configurations (tapered downsprue) would not allow this.

So I am saying your suggestion is not reasonable.  You may have been able to make multiple pours in your shop or backyard, but it's NOT an industrial process or practice.  It seems the parts you showed are very simple in configuration as well.  Parts with a longer draw would cause problems.  I have spent a good many years in sand foundry and these statements come from this and my previous education.  Oh, I've also visited the foundry that produces most of the sand cast muzzleloading parts.

I hope this clears up where I am coming from.  One thing for sure, this isn't worth wasting anymore time on.  I'll bet we can at least agree on that.

Jim

[Cory Joe Stewart]

I was cleaning up my trigger guard today.  It is from RE Davis and was very fine quality, there was one little divit taht I left in it.  It coupld have been filed out but I was afraid with my inexperience I would change the shape too much.  I started with files, reshaped some of the parts of the guard then  made very liberal use of sand paper, down to 0000 steel wool. 

I did learn the benefit of CARDING YOUR FILES. 

Coryjoe

[Captchee]

 jim the parts i showed you are simple  because i just threw them together quickly . you want me to show you TC and Butt plates ?  i can  to include  brass ands sterling .. I still have a few here  to use before I cast more .
 I believe I also have  on TG that’s  from a double  casting in the same mould .  Not to mention a couple butt plates  for old production guns   that  have the toe plate cast  with the butt plate all as one
Ill  look  and take a photo for you  tomorrow

as far as i know though  , there is not anyone actually sand casting our parts  in a truly commercial setting.
 Now I could be wrong but  as far as I know , those doing the sand casting are doing it in small runs , throwing multiple castings at one time . Not some big commercial type foundry .
 But then again , maybe they are and that’s why the parts look like a  engine block  prior to sandblasting

 The spru comment makes no difference because the parts are not cast downward but on their side .  Excluding buttplates which can be done a number of ways
One could have a spru that looked like a snake  and its still going to lift from the mould . Go out an look at one . If its not a lost wax casting , there will be a casting line down the side .

  Ill also accept that MAYBE they are not  re using moulds. But the point still stands that it can be done .
 But  for the sake of argument lets  say they are not .
Explain to me then why it is that the casting now look as they do ?
 Poor quality sand ?
 Pour quality binders?
 Or just plain  poor pounding of the moulds ?
 Whats left ?  
 Some of these parts  being sold look as if  they were cast  along the river bank
 Then we have a poster right here  who possibly is running into  filing through sand .
  Where did the sand come from and why is it there ?

I was cleaning up my trigger guard today.  It is from RE Davis and was very fine quality,

 and im willing to bet that it did not look like  it was coverd with brass or silver sand  , did it

[Captchee]

here you go



 top brass TG is a double casting


 see the cast line on the side of the tapered spru ?


close up of the double casting


 

[Acer Saccharum]

Great finish on those castings. I have seen sand castings with sand encapsulated in the surface metal, probably from poor ramming or poor sand quality.


Lost wax leaves a much finer surface on the parts. The mold material picks up every little detail, even fingerprints in the waxes. Waxes are used in ceramic shell process and investment castings.

[Jim Kibler]

Captchee,

If you would like to spend time making, contemplating or debating about re-used sand molds, that's fine, but I don't have the time to waste.  I consider it a ridiculous idea and anyone you ask that actually has experience in the sand casting industry will likely agree.  

Just saw your last post.  The close-up of the guard shows a casting that doesn't appear to be very good quality.  Wouldn't be something I would want to use.  As I said, I wouldn't even consider re-using molds.

On to something more significant.  Think I'll clip my toenails.

Jim

[Captchee]

what ever you say jim
 you exsplain why many of the casings today look the way they do .
when you figure out how  to sand  cast a tappered sprue so that a TG is cast from the top  instead of the side , i would enjoy reading about it  becouse the only way i know to cast even a tapered spru is from the side as i showed with the sterling silver  TG above . but i guess my stuff doesnt meet industry standards .

yes Acer lost wax does make for very nice castings . i have not done that type of casting yet .
 one of these days im going to hit up Jerry H to show me how he does it

Just saw your last post.  The close-up of the guard shows a casting that doesn't appear to be very good quality.  Wouldn't be something I would want to use.  As I said, I wouldn't even consider re-using molds.

and thats my point . thats exsactly the type of castings  being offered all to often today . but then you know that dont you .
 i guess you missed the part of it being a double casting from a used mould