Last night I had a basic solution, presumably with little freebase dmts floating around in it, to which I added about an equal amount of acetone and stirred gently. The mixture has been in my closet all night, but no separate layer of solvent has formed. There's just a layer of crud at the bottom of each jar with a bunch of amber liquid on top of it. Was acetone possibly a bad choice?

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Are you following a particular TEK, slewb?

Yes acetone was a horrible choice, sounds like you need to read a lot more before extracting. You cant just substitute solvents without understand what each solvent's properties are. Please check the links you received in your welcome pm, such as the FAQ and the wiki and health and safety sections.

Read through a few different teks and understand why each step is being done. Acetone mixes with water, it will never separate from your mixture. Now what you need to do is to let the acetone evap, if you have a (no-sparks) hotplate or similar flameless heating method you can use gentle heat to help evaporating the acetone. Make sure no sparks or flames!!!

Once mixture is clean of acetone, use better solvent.

For your own safety, please read all the recommended links.

I'm not using any particular tek, since many/all of them require materials I don't have access to where I am now, the fancy solvents being among those items. Anyway, if all I need to do is evap off the acetone and then use a different solvent it doesn't seem like such a huge deal. Thanks!

Maybe it hasnt been a big deal yet but if you made such an elementary mistake as mixing acetone with acqueous solution and expecting it to separate, then Im not sure if you have understood the general processes and gotten all the safety concerns correctly, or if from now on you wont make another big mistake. I mean no offense but I seriously think you need to read a lot more before continuing your attempt.

What solvent do you want to use now?

Thank you endlessness, for I do appreciate the concern. I have read most of the a/b extraction teks on the wiki, I'm just an idiot who thought that acetone was a non-polar solvent. I'm thinking now I may use mineral spirits. I know it's not the best choice but I'll go look and see what else I may have lying around.

How will I know when the acetone is gone? just by smell?