Thursday, July 2, 2015

The Tale of Mr. Blister and the Half Assed Bear

Yeah, I don't know what the title means either. Read on and maybe we'll both figure out.

While I don't quite hate him at the moment, I wouldn't say we're friends.

Still building off my lack of complete failure the last go round, I decided to try the bear once again. I stuck with my method of making the internal portion separately as a "core", however, I decided not to shift the pattern. I still don't have a good solution for how to accomplish (or how to avoid) digging the runners in the cope.

The "core" came out nicely, thanks to a possible over use of parting dust with the exception of the leg (as expected).

The mold came out fairly decent though I did have a bit of separation in the bear's "crotchular" region. (I know that's not a word, but you understood what I meant, didn't you? So now it's a word.)

Placing the "core" back in went smoothly as well. I also was very meticulous about cleaning all of the loose sand. As I mentioned, I think that is the cause of the imperfections in the OF castings.

I had plenty of sand this time (thanks to a recent order that arrived from Mr. Thompson). I also added some additional weight, just to be safe. Now it was just a matter of waiting for the furnace to get to temp.

Quick aside, my neighbor and I took my jet ski to the lake this past weekend. For some dumbass reason, I completely forgot sunscreen and got one of the most heroic sunburns of my life! In similar dumbass fashion, I neglected to think about the infrared radiation as well as the heat from the furnace tonight. This is what it does to fresh skin... through a cotton shirt. Note the abundance of tiny blisters on my already blistered skin. (That's my arm, you perv.)

Anyway, it poured with out incident though I did have a little bit of excess to clean up where the core mates with the pattern. It was easy enough, a few clips with the tin snips but, in the future, I may try to make an additional, sacrificial core just to use to make the molds.

Once that was out of the way, the casting turned out mostly okay. It is by far the best one yet. It seems that some additional sand must've come loose and fallen in the crotchular area, either when I set the mold down or while pouring. I'll need to pay additional attention to this area in the future. This ended up making this casting unusable since the area is incomplete, hence the name "half assed bear".

I still need to clean him up a bit but I think I might keep it, for now, as at least an example piece. 

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