Yodas!!!

Josh, you should post about your smoothing station.  How long and how many times did you expose the Yoda?  And what was its resolution to start?

So rather than messing around with a condenser, you just keep the lid of a crockpot in the freezer?  The cool thing about the steel stock pot is there seems to be a pattern of condensation followed by instant evaporation on the sides.  It shows as a slightly darker shade where the vapor is, and you can practically see it sloshing around the sides of the pot.  I can see it drop lower in the pot as it cools, and can tell when it's time to add more hot water to the outer tub to make it deep enough for whatever I'm putting in there.

As for flammanility it might be different for vapor (and maybe not) but the wikipedia entry for acetone notes-

"Acetone has, however very high ignition initiation energy point, so accidental ignition is rare. Even pouring or spraying acetone over red-glowing coal will not ignite it, due to the high concentration of vapour and the cooling effect of evaporation of the liquid.[20] It auto-ignites at 465 °C (869 °F). Autoignition temperature is also dependent upon the exposure time, thus at some tests it is quoted as 525°C. Also, industrial acetone is likely to contain small amount of water which also inhibits ignition."

Josh, you may have already seen this post, but check out a different Yoda, printed and smoothed on the Stratasys machines-

http://blog.erikdebruijn.nl/archives/12 … es....html

A pot of warm acetone may not be safe for an office environment, but you can certainly get the same results in your backyard (or parking lot) for thousands less.  All you need is that small sandblaster and cabinet ($150-$200 total) for the complete set.  Stratasys has a "burnishing station" which is a sandblaster for creating matte finishes like the sample in the blog post.

What type of crockpot are you using for this? Hoping to utilize our not often used mini crock pot warmer (read no controls) that came with our full sized one. I pretty much know my wife will object to putting acetone in our main crockpot, though the WAF might be higher against a larger setup such as Ian's.

I think it would be easier just to buy one of these - http://www.harborfreight.com/abrasive-b … 42202.html than try to build something from scratch.

One of the problems in doing this is how to hold the part.  For some things, just setting it on a steamer rack of some kind is good enough.  For another I screwed an eyelet into the bottom and dangled it from some wire and hung it up to dry.  I was thinking a good solution might be a kind of "bed of nails".  Find a base material of something soft, and push some pins up through it.  The amount of actual contact with the model would be very small and the vapor would get at all sides equally.   I wonder if something like a pad of silicone would be non-reactive to acetone.

Yes

That's a great idea... I will try that on the one I am working on now for the entire process... I should mention I am actually using crushed walnut shells for the blasting... There was no dry sand in town...