Passing along some info and experience with another option for PTFE closures. So far is working well for aging in glass and other non-wood containers. I came across these sheets online while hunting for something cheaper and more flexible than US Plastics discs. They're available on AMZ and perhaps can be sourced other places as well. Cost is usually less than $0.10 USD each. These particular sheets are 4 x 4 inches which fits a wide variety of lids and caps. I've used them on wide & narrow mason jars (under lids and without lids), under metal caps on jugs and under plastic caps on milk bottles. Also secured with a rubber band on various other bottles and carboys that are missing a cap. I found them to be reusable and have never discarded one even after many on/off cycles and relocating from one size or type of container to another. Lastly, the sheets will seal very well, but are also easy to poke holes for air transfer.
One thing to be aware of is these came on the market, I believe, to support the growing "herbal" and botanical extract market in the US. From what I can tell, the market has migrated in the past couple years to using FEP which is a fluoropolymer very similar to PTFE. It has the same chemical resistance as PTFE with slightly different physical properties: FEP is more transparent, is a bit less flexible (less tolerant of repeated folding) and has a bit more friction. I recently bought some of the FEP sheets so I could test them ($12 USD for 500 sheets or 0.02 each). Haven't used them long enough to form a strong opinion based on real experience, as compared to PTFE, but so far they seem good too. For most it would probably be a matter of cost and availability, and thankfully there are more choices now than there used to be.
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PTFE sheets
PTFE, wide & narrow mason jars; two with bands only
PTFE, wide & narrow mason jar lids
FEP on left, PTFE on right
FEP on left, PTFE on right, imprint is from narrow mouth jar
PTFE on jars of torshi, one jar has clear FEP without lid; PTFE 1/4 sheets under jug caps
Last edited by BoilerMaker on Mon Jul 31, 2023 3:14 pm, edited 1 time in total.
WOW. Nice write up!!! I for one appreciate all your effort making this post. I am not familiar with FEP. Really never heard of it. Nice to know there is options. Thank for sharing this.
OK, adding a few examples.
(apologies to those that don't do amazon, I haven't looked for other sources)
HD forum s/w might be trying to pull in the page when I include the links, so replaced links with item numbers. Enter those in their search engine...
PTFE
Qty 500: B08JP7RG4C
Qty 1000: B079GSB7CH
FEP
Qty 500: B083LPM8XQ (B09GK7PFVF is perhaps least expensive, currently)
Qty 1000: B09DGPV3QC
BoilerMaker wrote: ↑Mon Jul 31, 2023 7:12 pm
OK, adding a few examples.
(apologies to those that don't do amazon, I haven't looked for other sources)
HD forum s/w might be trying to pull in the page when I include the links, so replaced links with item numbers. Enter those in their search engine...
PTFE
Qty 500: B08JP7RG4C
Qty 1000: B079GSB7CH
FEP
Qty 500: B083LPM8XQ (B09GK7PFVF is perhaps least expensive, currently)
Qty 1000: B09DGPV3QC
But polyfluoralkanes are known as PFAS and both the production and the disposal are very bad for the environment.
Which the producing company already knew for a long time, but did not care about. So also very bad for human society.
The period of using is only a small part of the whole lifecycle of these kind of wonderfull products (asbestos, plastics, pesticides, silicones, PFAS).
