ptfe seal for airstill ?

[friendly1uk]

Edit: The pics are links, but the surrounding adverts are not work safe.

Got the all stainless model, so non of the usual problems of silicone pipe in the lid or a plastic outlet spout. However it has the little talked of silicone main seal. About 75cm of silicone that makes the other issue's pale in to insignificance. This caught be by surprise, like an elephant in the room. I gotta fix that...

Looking for pics I see a new seal 20 miles up the road for a tenner, but no explanation what it is. This is odd, as till now all I hear is people say the still is dead when the seal fails. Some really bad info floats around about these things.

Gonna have to take a pic, I can't find one.
omg, imageshack wants me to sign up. Now what. Halted in my tracks.

Can anyone pull any useful hidden data from my image?

There you see how the top drops in to a tubular pot using the silicone seal. The lower lip is metal, but sits on nothing. The while plastic case sits on the pots lip to stop it falling right in.

In this next pic you see a flat ring on the table, and how it sits in a tube of slightly narrower dimensions.


I'm thinking that white seal could be ptfe. I would put it right at the top of the pot and let the lid push it down. I'm relying on the fact it is too big to help it seal to the pot, and the fact it is slightly supple to keep it against the pot lids protruding stainless lip. As long as no vacuum is pulled. it should stay there. What little pressure does form should keep it in place.

Now, I'm not fussed if it aint perfect. Even if it leaks a bit, the silicone won't be as hot as usual, or washed down as much as usual. It is better.

I'm here to ask what thickness this should be? I realise this is materials science and maybe nobody can help, but all I have ever played with is 0.25mm thick for jar lids. It is likely to deform with little uniformity. I reckon 1mm will do it, and 3mm would be too thick. I just don't have any experience though.

An A4 sheet of 0.25 costs me £3+P&P so 1mm will be about £10. I was looking at much thicker for another option I have, but it was £30 and the still was just £80 so that is not cost effective.


Any thoughts?

[MitchyBourbon]

I thought I'd wait a while to see if anyone else had some ideas cuz I really don't. What I do have to say probably isn't what you were hoping for... I don't think I would put any more effort into fixing that still. You can try ptfe tape but I think you are right that you will have trouble getting a uniform seal.

I think your best bet would be to build your own still.

Just curious, how well did that still work for you?

[friendly1uk]

I thought about tape, but a reel an inch wide is a costly thing to keep using. Quite rare you see. I'm talking about sheets of the stuff. It is quite tough. In no way brittle, but harder than rubber. Without using the stuff peeps won't be able to provide a solid answer, but I'm happy to hear any ideas. I can get a sample pack for £3 delivered that contains 1mm 2mm and 3mm. I might just buy a sheet of 1mm though, I can use in it jar lids anyway.

Having put £80 on the line, I would like something from it I could pass around. Lots of peeps use them, and the distillate has been tested and shown to carry only a trace. Still, people here will be pulling there hair out at the idea, and I agree.

It is a pot still, so will never be great. My hearts cut is 75% abv though. On a run where I collect 825ml of hearts, I chuck out 300ml before it and about 400ml after. Hearts starting around 85% and finishing at 50%. This is just from a 2L charge, which must be close to 40% by my reckoning.

I ran some store bought vodka the other night. Didn't loose much at all. Just chucked the top 50ml as it stunk. Then it made a nice neutral.

I have a stainless kettle too, that uses a linear condenser. It is hard to separate them.

Many people love beating down on them once they get a reflux. That is just human nature for some. We have a lot of peeps here that like to give a beating to anything they can, but if you can see though that you realise it is just another pot still. You need some sort of power regulation from the word go or it is at a disadvantage, but otherwise, it's just a pot still.

Remember I joined this site a few days after I started thinking about brewing my own. I'm a proper newbie, but not a daft lad. Mine is not the voice of experience.

[MitchyBourbon]

Well I have no experience with an air still, I know they don't have the best reputation around here. Hope you get it sorted out.

[friendly1uk]

One gripe I have is the size of it. It makes a bottle at a time. As I'm new I want to drink it, so where is my one to save. I can't possibly do another strip and spirit run of the same thing. There are just to many other recipe's I must try right away. Then there is my need to share my new hobby with anyone interested. A bottle at a time might not be enough. They have to be run quite slow if you want a fair pot still result. Disadvantages that might make you steer clear. The price though... Just so cheap. You get a product for very little money. No naked flames or fixing leaks. You can walk off and return when a stopwatch tells you once your familiar with one. It can work for some people, when other things won't. For me, I thought it would make enough, which it does, not the product I'm looking for does not really come from a pot still at all. You gotta get a benchmark somehow though. Tried two now

Thanks for your input. I will let you know