First run PLA vapor smoothing, safer than alternatives (similar to acetone). Hoping to post on it this weekend or Monday. We think it has potential for long term adoption. (NOT Dichloromethane)
Then what chemical is it?
I guess you are trying to patent it? Or why else tease without info? 
Because what would life be without suspense! But for the impatient: Tetrahydrofuran
is the primary use/idea to have a less dangerous solvent for many uses outside the lab-- or is this primarily for research & lab ? sorry, i’m a geek so i like these topics but don’t really know much chemistry or info on this particular subject at all, seems good however if indeed a less volatile /dangersous/toxic ingred for solvents if reaches scale for industry or public use
Definitely outside of lab. The smoothing on that tooth somehow makes it so much more real; holding it makes me feel like I did when I first learned about Dinosaurs! Everyone should access to that.
Any movies, or more pictures?
Yep, we’re going to try and investigate the ‘explosive’ thing a bit more; so far so good though.
Usually THF has an inhibitor, so it would have to be quite old in order to form the peroxides. However, viewing the videos of peroxide explosions, please do not play around with this- they’re very very dangerous. Online research or contacting suppliers should help figure it out. I believe the stabilizer/inhibitor was BHT if I remember correctly. Ethane does this as well, if I remember right.
Which supplier did you use? I’m working with the Georgia Tech Invention Studio and we’ve been looking into getting some THF so we can expand vapor polishing to PLA parts.
BTW by “play around with this” I mean don’t try and make the peroxide crystals themselves. It’s a primary explosive which means it requires nothing else other than shock to detonate. THF is a great solvent, however, and have used it in the lab many times, it’s safe if it’s fresh(ish) and inhibited.
That looks pretty impressive. How long did you polish with this? And did you use roughly the same procedure as ABS and acetone? Someone mentioned “sponginess” or “softness” in relation to I think dicloromethane, did this behave similarly?
@Daniel_Roberts - a good solvent is likely required to polish with, and this will definitely allow solvent to partially dissolve the upper layers of plastic. Any absorbed solvent will make the plastic feel spongy or soft, but can likely be baked out at the solvent boiling point. (heat again after the polish is to your liking but without a vapor of solvent- to evaporate excess solvent in the upper layers) - I should add- I don’t have a printer to play with myself right now- this is based on my experience playing in the lab.