Hello,
I am a bit confused about the stance on plastics as part of stills. In the FAQ it says:
Plastics have no place in the distillation process (other than HDPE containers can be used in the fermentation process).
But other places all over this forum and other folks talk about using PTFE or more commonly known as Teflon as gaskets and tape. So is Teflon an acceptable plastics in small quantities? If so is it ok to use NPT threading and Teflon tape to make the seal over tri-clamps?
Dr_datto wrote: ↑Mon Apr 20, 2020 2:39 am
How fine is fine? Is a boiler with Teflon coating fine or should it really just be for joints?
You got a “teflon coated boiler”, doctor? If so, I don’t see a reason not to use it.
Don’t be a troll... Polytetrafluoroethylene (PTFE) is a good material for use in a still because of its chemical resistance even in harsh, high temperature systems. The MSDS (material data sheets) have shown it safe for our intents and purpose.
But with your “teflon coated boiler” are you 100% sure that the coating is ONLY teflon? It’s not some space age concoction developed to keep your eggs from sticking to the pan? If you’re confident enough to try, then good luck with it. And you can report back with your witness report...hopefully! If you don’t, then it probably wasn’t such a good idea, huh?
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Having a bit of experience in Teflon coatings, they are not pure Teflon. They do contain Teflon and lots of other stuff to be able to form a coating, flow out, and adhere to the object. Some are more pure than others.
Interesting thing about ptfe, it has holes in it. This is why it can be stretched into a film and used as goretex. Pfa on the other hand is a thermoplastic and flows out leaving no holes. Had much better release as a coating.
I don't mean to be a troll all my experience with plastics is either as Tupperware or very high purity scientific parts. I don't know what will happen when distilling with consumer products. I checked the reactivity of Teflon versus expected solvents, but I assume those charts are at room temperature, and y'all would have more experience at higher temperatures. As for a Teflon coated boiler, I think tea kettles often are coated with Teflon. I don't know how often stuff gets burned, but I know I burn sh*t while cooking all the time.
That is very cool to know that Teflon is porous. I had no idea. I guess that is why the blocks of it look white and not clear...
What about buna N or Viton? These are common o-ring materials for my labs, but I can't test there now due to COVID.
I don’t want to hijack this thread but as ptfe gaskets and ptfe gaskets get brought up from time to time I be wanted to point out that if you look to places that supply gaskets and fittings to the food and dairy industry you can get Teflon envelope gaskets for tri clamp fittings. They are softer and seal better that regular ptfe ones as they are a normal epdm gasket with a 3 sided cover of ptfe over the product contact surface.
They won’t be cheap but they will hold up, seal better, and will meet the standards set by this community.
