Foundry Faux Pas

Sweet Anticipation

Casting reminds you of a childhood Christmas when you unwrapped your gifts to discover... what? A technical lego construction kit? A new shirt? We've rammed the mold, we've poured the metal, we've waited patiently for the casting to cool. We have a few hours of labour invested in this thing- and it will be wasted if something went wrong. So is it candy or crap?

Awww Crap!

Unfortunately it is the latter. At the left side of the mold we see the metal did not fill the cavity entirely.

Here's the side to side comparison between the pattern and the casting. The casting has gone Daliesque on me. Conclusion- the metal was not hot enough. It was molten, but it did not stay molten long enough to reach the outer extremities of the cavity. Solution- Make sure it is hotter next time. Even after the metal is molten give it a few minutes on high blower with the furnace lid on. The metal should be glowing light pink when poured.

One good thing about casting- you can re-melt your mistakes. No one need ever know.

Slow Learner

Oops, I did it again. The one on the right turned out ok. The one on the left was poured too cold. This was a two pour mold. I poured the smaller casting first and the larger second. I should have poured the larger one first, and made sure the metal was hot enough to start with. Oh well- the smaller one was good. You will notice that the core has broken off within the casting. This is just like a core, except it will generally break off in the pattern.

Here we see the bad casting and its corresponding pattern. In the spirit of learning from mistakes we can see the otherwise hidden pattern of metal flowing through the mold.

Redemption

Just to prove I can get things right.