Good idea with the aluminium foil, should be easy enough to clamp it down between the rubber seal and glass top of the bottle. Looking forward to giving it a test run!

EDIT:SWIM idiot forgot
still got a noob question how do u know when u can't pull anymore?

I absolutely do not recommend using aluminum foil with a basified solution, if you are using lye.

When you have a jar containing only your solvent, aluminum makes a good barrier between solvent and lid. But I do not recommend allowing aluminum to come into contact with a solution containing sodium hydroxide. Here's why.

From my understanding, sodium hydroxide will partially degrade the aluminum (possibly leaving impurities in your solution) and more importantly, it will create hydrogen gas.



So I repeat:
I ABSOLUTELY DO NOT RECOMMEND USING ALUMINUM FOIL WITH A SOLUTION CONTAINING SODIUM HYDROXIDE (LYE).

But if the extraction vessel is vented regularly after the lye is added, and the surface area of the aluminium that it is making contact with is quite small (less than 1" in this case), and the amount of lye is fairly dilute (50g in almost 1L of solution comprised of bark/vinegar/water/salt/naphtha) then surely the effect would be negligible?

Apart from getting a different extraction vessel, what other alternatives are there? A cork? Rubber bung?

With the sizes involved any reaction/effect would be so minute as to be moot.
As you say the surface area is tiny and dilution is weak.
Any hydrogen produced would equate to a gnats fart.

Great of Entheogenerator to bring up the safety issue though

If you feel worried then you can always use a cut down cork or fashion a bung out of something.

The use of aluminium with caustic soda is not discouraged - it is actually SEVERELY CONTRAINDICATED!!!

No amounts of "NaOH dilution" or "contact time" can ever justify doing something so sloppy, dangerous and unprofessional as mixing caustic soda and aluminium - let along when the aluminium is supposed to "protect" from the obvious and imminent degradation of the rubber washer from the naphtha. Are you guys serious?

Either use another vessel without rubber or go for the safer option of a cork - even though cork itself is also slowly degraded by NaOH.

Firstly, I haven't actually used the aluminium foil yet. This discussion was about the pros and cons of using it. Why does that make someone like me who is very new to extracting (and chemistry in general) "sloppy, dangerous and unprofessional" and seen by you as not "serious"?
I'm not sure what else I am supposed to do. I never claimed to be a "professional" (and frankly don't even know what a professional DMT extractor is) and was simply trying to examine my options for a safe and practical extraction vessel in light of my limited knowledge.

Please receive my apologies if my liberal use of the plural form of the word "guy" was misinterpreted to include you.

It was cyb's post (as per quotation) that I criticized. Please do not use rubber and/or aluminium in any way during an extraction.

Okay duly noted. Ended up going with the cork, not the best of seals but it did the job.