Tried a core casting today. I had trouble getting the core placed and flask put together but thought it was OK.
Here's the core, 2 halves and the support parts. Glued together with flour paste. It seemed really hard after I baked it. It wasn't too strong when I took it from the mold I used my homemade Sodium Silicate.
Put the pattern halves in and then I cut in area for the supports.
Didn't look bad at first, turned it over and the bottom didn't fill. The core was too far down and it was less than 1/8" thick. Should have been about 3/8"+.
These came out better, little lead soldiers and a guy carrying a pig.
I tried some other small brass parts and they didn't come out either. I didn't let the brass get so hot this time, must not have been hot enough. The last time the Zinc burst into flames when I poured. I'm using the 65% Cu, 30% Zinc, 5% Lead. machinable yellow brass. It melts well and pours like water but is really smokey.
Made some scrap or Art..?
Made some scrap or Art..?
quando omni flunkus moritati
Re: Made some scrap or Art..?
thought that come to mind really fast is your pattern might be a good candidate for a horn gate, you may also want to try some chaplets of the same material to hold the core up from settling.
DA
DA
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
If life seems normal your not going fast enough" Mario Andrette
Re: Made some scrap or Art..?
I thought about a horn gate. Not enough room in the flask and my attempt at making a horngate pattern failed, looked like something kind of nasty. I know I needed a larger sprue, closer to the pattern. My main problem was the sand was too dry. I should have got it out the day before and added water so it could even out. Next time I'll put something in the sand to support the ends of the core, it was pretty heavy. I thought it would be a good idea to heat it before the pour. Didn't work too well, no way to hold on to it with gloves and I had it at about 500 F.
I should have noticed all the problems and started over. I just got stubborn and pushed ahead.
I should have noticed all the problems and started over. I just got stubborn and pushed ahead.
quando omni flunkus moritati
Re: Made some scrap or Art..?
don't we all, they finally lifted the fire ban here so I can pour now if I can get other things caught up like replace the motor on my big mill that burned up.
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
If life seems normal your not going fast enough" Mario Andrette
Re: Made some scrap or Art..?
Whats the ball for Jammer?
I like the "Lead men"
I like the "Lead men"
I like to build "Stuff" using Stuff that costs Stuff All!
Re: Made some scrap or Art..?
It's a hollow brass ball that I plan to fill with lead. Braze some brass plugs in the holes and have a practice shot-put for my son. He throws the shot-put and discus in track and wants a 16 pound one to practice with. So when he throws the 12# one it really seems light.
They make a 16# one but it's cast iron and pretty large. Plus it's expensive for a chunk of iron.
They make a 16# one but it's cast iron and pretty large. Plus it's expensive for a chunk of iron.
quando omni flunkus moritati
Re: Made some scrap or Art..?
Do you plan on having another go at casting it?
It is interesting that it was the bottom thet didn't fill. Cores normaly float! So that would mean that it must have set been like that before the mould was closed. Or the core print was not cut into the cope enough and it pressed the core into the drag when you closed the mould up.
Better luck with it next time!
It is interesting that it was the bottom thet didn't fill. Cores normaly float! So that would mean that it must have set been like that before the mould was closed. Or the core print was not cut into the cope enough and it pressed the core into the drag when you closed the mould up.
Better luck with it next time!
I like to build "Stuff" using Stuff that costs Stuff All!
Re: Made some scrap or Art..?
Yes, I will try it again. I doubt if I had the core print right, I probably pushed the core down when I closed the mold. Like you said.
I'll have to set up the mold a little better.
I'll have to set up the mold a little better.
quando omni flunkus moritati