Saturday, January 23, 2010
Today I rammed up the pattern for the water pump housing, fired up the foundry and chucked in a couple of old pistons and a top fork crown from an old Honda ATV. In 25 minutes or so I had a nice crucible full of molten aluminum. As I poured it into the mold, my gut feeling was that it was going to be a bad pour. I was wrong. It was a horrible pour. I think the sand was too wet and steam filled the upper part of the cavity instead of the alloy. No big deal. I'll allow the sand to dry out a bit and try again later. It's been about 5 years since I messed with the hot stuff, so I'm a little rusty. I have plenty of time and the cost is next to nothing, so I'll keep on trying.
The second pour was another failure. Not as spectacular as the first, but a failure nonetheless. I didn't allow the aluminum to get hot enough and it began to freeze in the crucible as I poured.
Though I melted enough metal, I came up short and the mold didn't fill completely. All was not lost, however. The casting is unusable but, other than a large hole in the back of the housing, it came out rather nice. Let's hope that the third time is the charm. If I had a pyrometer, I could avoid the guesswork but it's not in the budget. They didn't have fancy stuff like that 100 years ago and they did OK.
It's too late today to do another, so I will have to wait until tomorrow. Stay tuned.