Monday Metal Madness. First ceramic shell pours.

I cast my first ceramic shells on Monday. Aluminium and brass.
Aluminium 1.....Brass.....0

I used Jason's boil out method on the shells and it worked a treat. Very, very pleased with that.
The Aluminium was a success the brass not so.
The quality of the molds is definitely up using ceramic shell but it is time consuming. I need to be
more quality conscious of my wax pattern making. It is getting there though.
With the casting, I was too excited and needed to pay more attention to the metal,
getting this right before attempting pouring, degassing, use of flux and
making sure it is plenty hot enough. If anyone has any tips or can point me to threads or videos on this I would be grateful, particularly on brass. I have seen Myfordboy's very instructive videos on aluminium.

Quite a few lessons learned!!! It's not put me off.......more shells in process!!!

 

Hi DavidF,

No I didn't have a cover. Previously I've stirred in borax and put bbq charcoal on the top of the crucible. But I was too over excited about casting into these shells that I forgot everything. I will make a short vid of what I am trying to cast and how I set it up and show the result. You will probably be able to help me there. I would very much appreciate that.

I haven't forgot about doing a vid on making my crucibles. I'm due to make some more shortly.

 

Congrats Jimmy. Saw your video last night. Glad to see shell worked for ya. The shell cracking a few minutes after you pour is normal. The cooling metal is shrinking inside and is what breaks apart the shell. I am not a fan of running stuff under water. I have cracked stuff doing that. It was sprues and vents, but it could have been part of the casting I cared about. I have also noticed that it makes the shell more difficult to remove as it doesn't give the metal a chance to break the bond off the shell. None of this might matter for aluminum as I only run bronze and the temps are considerably higher. Congrats too on running the boil out method. I wouldn't say it is perfect in all shell plumbing arrangements, but if ya keep it in your mind while spruing it works well. I remember the guys here schooling me on my upside down feeders which can introduce air and turbulence. By dumb luck or my ignorance was exactly what was needed for boiling out.

 

Some nice looking castings.

 

Nice work Jimmy.

Some close ups of the brass roses might help some of the guys on here give good feedback. But, your statement regarding temp & degassing might be the answer. Pouring speed as well.

I need to look into the waste oil side of this hobby.

The clip made me wonder...
How many of us have trampolines in our backyard? They take up some space. If my son didn't still jump on it every day, it would have been gone 2 years ago.

 

You do not want to know what I have done on a TRAMPoline

 

Here is a short video of what I am trying to make. They are door handle roses in brass. I have actually made some using green sand but they took quite a bit of finishing. They turned out well though and are fitted. The green sand molds were hard to make though and I had a lot of failures. Anyway any help/ suggestions would be most gratefully received.

 

Did ya see my comment on the youtube page? sorry, maybe I should have posted it here.


Copied from youtube. This info should remain with Jimmy's post for the next poor sod with a similar issue.
"Sorry Jimmy I can't help you with brass. I personally think it's nasty shit that's why I don't pour it. ;-) I do think your sprues are a little on the short side. I would be more inclined to build a 12in long sprue and attach them onto it with a traditional pouring cup.... This added height will increase pressure and help your stuff fill. 1inch for the main sprue, 3/8" feed each door rose and then maybe an 1/8" off the lip off each one for a vent. Ceramic shell is porous and does vent through the shell, but I am a belt and suspenders kinda of guy, that's why I recommend a little vent."

 

Yes got it thanks Jason. Bigger sprues! I'll let you know how I get on with the revised sprue and vent layout.

 

Just longer and taller. Gets you some head pressure. I think that's why ya didn't fill completely last time. That shitty yellow metal was probably fine.

 

My yellow metal is quality Heinz 57 variety! :-D

 

If it's free, it's for me and I'll take three! If you ever pour sil-bronze, you'll forget all about brass. I love working the stuff. It pours beautifully, works with simple hand tools and a dremel and best part, it tig welds like butter! You can polish it to look like gold, but it corrodes insanely fast. One drop of sweat on it and you'll get my drift. No zinc nonsense and people generally respect the material over brass. Funny how brass it's close sister can be downright nasty. The ancients knew something and they preferred bronze over brass. No one will usually pay jack squat for something made of brass, but bronze is a different ball game. Maybe it has something to do with cheap brass trash from India?

 

Ha, you read me like a book!

I definitely will get up to working with Bronze, I have a few "art" projects in mind, but in the meantime I have my lovely "free brass" to melt and mess around with together with my "free waste oil" and work up my skills and techniques ;-) I've got a lot to learn.

 

Second go, a much much better result.

Still a way to go though ....and Jasons comment about the brass is true. Too much dross and rubbish in it. It needs refining before I melt and pour it. I need to address that.

I fired the shells in the furnace at the same time, with the metal, and used them at the same temperature as the brass. Seemed to work well that. The better spruing configuration worked too. So, much learned. A good day and a good well improved result for a new boy.

 

Uh no Dave.. Its copper, nickel then chrome. I've payed for tons of chrome work. No brass in triple plating buddy.

 

Glad to see it worked out for ya Jimmy.