08-07-2013, 01:28 PM
DA
Got a question for you, 1st not saying it is wrong but I learned a different way. Sprue = part = riser (s) My sprue cutter is 1 1/4" cause that is what the brass sink drain extension is. riser are 5/8" or 3/4" hard copper tube. And the goal is to fill the part and have it come up the risers, while it is still hot and the pour is good they sort wobble / shimmy (hell I can't think of a better way to describe it) at the tops of sprue and risers. Now many of my parts are quite thin, 1/4" thick or less. Since aluminum does not have the mass of cast iron or brass it is more likely to cold short the pattern (not fill out) On a thick part there probably very little difference but on a thin part with a thicker section maybe starved of metal. I see John DoubleBoost did it that way on one of his casting video (may not have noticed on others) I learn my way from HS tech program, but we had a local foundry man who made sure we were doing it right. He started sweeping the floors and ended up running the company 25 years later. his name; Gene Snyder RIP My friend a super nice guy. Same technique aluminum or brass, and we are using oil sand, got it cheap!
The part looks good! you must have gotten up before the chickens and the heat! now you can take the rest of the day off!
Got a question for you, 1st not saying it is wrong but I learned a different way. Sprue = part = riser (s) My sprue cutter is 1 1/4" cause that is what the brass sink drain extension is. riser are 5/8" or 3/4" hard copper tube. And the goal is to fill the part and have it come up the risers, while it is still hot and the pour is good they sort wobble / shimmy (hell I can't think of a better way to describe it) at the tops of sprue and risers. Now many of my parts are quite thin, 1/4" thick or less. Since aluminum does not have the mass of cast iron or brass it is more likely to cold short the pattern (not fill out) On a thick part there probably very little difference but on a thin part with a thicker section maybe starved of metal. I see John DoubleBoost did it that way on one of his casting video (may not have noticed on others) I learn my way from HS tech program, but we had a local foundry man who made sure we were doing it right. He started sweeping the floors and ended up running the company 25 years later. his name; Gene Snyder RIP My friend a super nice guy. Same technique aluminum or brass, and we are using oil sand, got it cheap!
The part looks good! you must have gotten up before the chickens and the heat! now you can take the rest of the day off!
oldgoaly, proud to be a member of MetalworkingFun Forum since Jun 2013.