So this is starting to become a nuisance over the weekend and has caused me to abandon a run twice. I wanted to get some opinions and I am also hoping Larry might stop in here as well.
I have an SD flute and I love her ( http://homedistiller.org/forum/viewtopic.php?t=61788 ). Since the photo I have changed to a 4" opening on my boiler and eliminated the 2" to 4" section you see in the pic. The SD flute comes with silicone gaskets and I decided to go PTFE. Doing so was no easy task:
Standard bubble plate (without the caps)
Standard PTFE ring
When these to are seated you can see they don't match up well:
The plate sits so I I cannot actually clamp the TC clamp over the union. I decided to makes some changes to the PTFE.
I decided to grind down the center section of the PTFE ring to better seat the plate.
Modified PTFE/ regular PTFE/Silicone
Looking at the two together:
PTFE/Silicone
Then I used them in the still... I started to get small leaks. I figured I would grind down the PTFE a little more to be sure the plate was seated below the weir of the gasket... still leaks. So I decided to grind down the edges of the plate a little... still leaks.
Mind you these leaks are small and cause only an irregular trickle of product down the side of the column...but they're leaks! The leaks always occur on the hinge side of the TC clamp as well for what that's worth. I am about to go back the the gaskets from SD (I will not remind you what they are made of) because I did use them a few times before I had the PTFE and didn't have any leaks. I don't think anyone makes the PTFE gasket similar in shape as the silicone one but I could be wrong.
Another option for me would be to switch to perforated plates, I bought them when I bought the still because I wanted to try both options. I preferred the bubble plates obviously (albeit for mo specific reason).
Has/does anyone had/have a similar problem with PTFE and have a viable solution?
Last edited by rgreen2002 on Sun Nov 20, 2016 10:37 am, edited 1 time in total.
After grinding down the ptfe rings, that they look similar to the silicone ones, you could wrap them with teflon tape. When using the ring for the first time, it will get pressed to perfect shape.
I am not sure, that it will work for your still, but at my still I use two ptfe-in-ptfe-rings. Teflon sheet cutted to a ring and wrapped after that.
In this way, imperialism brings catastrophe as a mode of existence back from the periphery of capitalist development to its point of departure.- Rosa Luxemburg
Thanks der wo. I was thinking about wrapping them in PTFE tape earlier but the pressed fit you were thinking of would go away as soon as I broke down the still and put it together again. Unless of course I numbered the parts and put it together the same each time.... which I am not above doing in any way!
I figure that I shouldn't have to and that all the parts should be interchangeable but who knows.
Would PTFE O rings be a viable solution ? They're out there but one must know the I.D. as well as the O.D. needed to place an order and I'm too lazy to dig out the calipers.
Wondering if the "groove" of the tri-clamp fittings are compatible with a stock item on the shelf.
Thinking that this would be an excellent marketing opportunity for the distiller mfgs.
Yes. Once compressed, it will stay in this shape. But this shape will fit better than anything you can achieve with grinding or cutting it down. The better the shape, the harder the material can be without causing leaks.
Here a picture:
You see how the pressure has formed it from a plain sheet into a profile.
Or is it possible to increase the pressure on the sealing ring?
In this way, imperialism brings catastrophe as a mode of existence back from the periphery of capitalist development to its point of departure.- Rosa Luxemburg
In addition: I made a gasket of corrugated cardboard winded with teflon-tape. But I leave it in place, which is easier than your case.
Another measure I sometimes take: wind teflon tape on the outside of a leaking coupling. When you stretch the tape it will stick in place and small drops (like sweat or so) will be stopped.
FMH: I would think the same thing... Somebody must want to make some $$ off of this? The O rings may be a viable option but I would have to really get the calipers out myself.... and by out I mean buy some...
der wo - in the end I decided to wrap the offending gasket. I really wanted to get the run done and I expected it would take care of the problem at least temporarily. It did and there were no leaks.
Now since I have 5 section with 2 tc joints each plus a dephlegmator with two and a 4" to 2" reducer.. that's 13 different tc unions. Unless I put them together the same way every time the pressed fit joint would get lost in the mix. However.... in reconsidering this I am hopeful that the machined tc sections will be similar enough that it will be OK no matter where the gaskets end up in the mix.
I plan to wrap all of the gaskets before my next run to see what happens.
So I have go a bit of a differnt route that may help. I nonlonger use an insert gasket to seal between Triclamps. Instead i wrap each triclamp with ptfe tape so that the outside edge is wrapped and it covers about 1/2 inch of the outside edge of the face also.
A few wrap on each makes up the spacing for getting a good seal with a triclamp. They last for months ( many many runs) and rarely if ever leak.
HDNB wrote: The trick here is to learn what leads to a stalled mash....and quit doing that.
Been there done that: PTFE isnt elastic, and your column isnt perfectly circular. Use the silicon gaskets instead, too difficult to get it working on PTFE
