Sand Casting Suggestions

I've worked a lot of construction and I took HT1's comment as a good natured jab. I thought my response showed that. I also spent years in oil refineries. Tough crowd sometimes but I love it. If you show up at my shop get ready for plenty of "that was a dumb shit move!" Granted it's very tough to convey in a forum but "if you can't stand the heat get a new hobby whimp" suited me just fine because I knew where he was coming from. I didn't take his advice to get a new hobby because I have plenty already, and no one is ever going to convince me to stop a hobby I have. He did not say stop this hobby (I guess he's inept with the language). I hope no one else is put off by a little friendly advice.

And I'm not going to blow $50 plus shipping on a thermocouple if I can make a cheap one work. Hell I've already melted this same scrap brass three times, I just keep adding the zinc and used oil is cheap. And, I am learning, although very very slowly.

To put things in perspective, my son in law is two years older than me, and a Navy veteran, code welder, and heavy equipment operator. He meets me, I'm a smart ass know it all engineer. We get along fine because we both know how to get a job done, not just talk about it. But it took a little while. It helped when I welded up a hydraulic line under his backhoe we couldn't get off, he couldn't see to weld the crack, and we couldn't flush it to get it clean so I gas welded it burning the oil inside to get a clean weld and it's held for twenty years. One of those jobs where gas is better than TIG.

Thanks for the comments gentlemen!

 

Perhaps a little lacking in the diplomacy department, but I have to admire the honesty.
There is so little of it going around these days.

 

if I offended anyone, Go read this thread,

http://forums.thehomefoundry.org/in...ement-mixer-muller-build.285/page-2#post-5437

you can stop when you get to My Muller safety Video


V/r HT1

P.S. Maybe I should Start A blog??? So I can share My most meaningful bits of Intellect???\

 

I for one can appreciate what the experienced guys say.
I have worked with all types over the years, and the guys I learned the most from were the ones who did not beat around the bush, and the ones who would just say "Look, if you would quit screwing around and do this (fill in the blank), you would be a lot better off.
And so regardless of whether you consider it positive or negative criticism, then you know immediately how you can improve yourself.
I consider any criticism as an opportunity to improve what I am doing, so it is all positive to me.

The people that I resent are the ones who sit back and watch you doing the same dumb stuff year after year, and they just chuckle to themselves and never say a word, and so you just keep doing the same old dumb stuff and never learn anything.

.

 

Limited success today. Two days ago I got a pretty good pour until the cope floated.



I clamped the flask down for the next pour.

I'm having trouble getting the pattern off the sand core. I put a hole in the pattern and made a piece of sheet metal to put in first so I can hold the sand firm with a dowel while pulling the pattern.



I cracked the core but the pour went ok.



That's a 1/2" sprue tapered to 3/8" at the pouring basin.

I dinged the inside of the cope mold with the top of the pattern while withdrawing the cope so I have a knot. Also some cold shuts toward the top of the part.



Or maybe it's a shrinkage crack. I tried to preheat the mold, but maybe did not heat it enough. The knot will grind off and the crack will weld if I get the same next time.

While I'm pouring I'm getting lots of smoke and white spots on the stream which I assume is zinc burning off.

Comments?

 

Probably poor choice of words on my part. A pouring cup at the top and basin at the bottom. Settling basin, as it were. I basically used a 1/2" dowel sharpened to 3/8" at the bottom, the pictures don't show that well.

 

I just screwed up, though. I was cutting the sprue off and cut it up just as I realized it would have made a great brass punch with a little lathe work.

Now I'm thinking about a hexagonal sprue

 

I poured the second cap today. It came out OK, still some defects to be welded up.



Pouring at 2,000F I get a steady bright green flame, zinc burning I guess. Is that normal or does my scrap brass have a lighter contaminant in it that's burning? Same color as copper phosphorous burning.

 

Normal. My flames are always green. Too much spilled into the chamber over the years. No easy way to clean it out makes a comforting green flame.

 

Yeah, I'm talking about the stream of molten metal going into the mold flaming up with bright green when pouring brass.

 

Is this sand burn-in?