Teflon Based Gaskets

[memetic]

I want to stop fiddling around with flour paste and get a somewhat permanent gasket to seal my boiler lid. My boiler is only 6.5 gallons (can only run with about 4 gallons (needed headspace)), so I am frequently removing the lid to empty and refill. The flour paste routine is getting very old. I've done a bit of research about Teflon based gaskets, but the material is extremely expensive. A 48" x 48" x 1/8" sheet is over $400 (and that is the smallest quantity I can buy). Besides flour paste, what other options has anyone had good success with? Is Teflon paste legitimate? Thank you.

[rad14701]

You will need to do your own MSDS research on ANY synthetics you choose to use on your still... Remember, MSDS is product specific and does not insure similar properties across the board... When in doubt, and when possible, contact the manufacturer directly and ask specific questions... However, when asking questions don't say your exact intended purpose for their products...

When it comes to high temperature high proof alcohol vapor, remember: Not all natural rubber is safe... Not all Teflon is safe... Not all silicone is safe... Not all Tygon is safe... And on and on...

[Bagasso]

memetic, rad is right about having to do an MSDS search before choosing. I myself am kinda tired of the flourpaste routine. I have been thinking about HDPE and found this bit of info here: http://www.newton.dep.anl.gov/askasci/c ... m03082.htm

Question - What exactly is produced from burning HDPE?
-------------------------------------------------
High Density PolyEthylene (HDPE) is largely a hydrocarbon with an approximate composition of:

C(n)H(2n+2) where "n" is a very large number, so the primary product of combustion in an excess
of O2 is CO2 and H2O. Some CO would be produced if there is insufficient O2. In addition
however, HDPE may contain additives and pigments. If either contains a metal then some
particulate matter will result (most likely in the form of a metal oxide.

This got me thinking that if setting this material (plain natural HDPE) on fire only releases carbon dioxide and water because that is basically all that there is in the molecule then there is really nothing for hot ethanol vapors to leach.

Of course you gotta make sure that you are getting has nothing added.

[memetic]

Thanks guys. I was hoping there was some material out there that I didn't know about that everyone was using. I remember reading about people using food-grade cork a while back, but I never did find any for sale. Looks like I've got some more work to do. No problem.

Another option I have been thinking of is to TIG weld the lid to the pot and create some type of threaded (or tri-clamp) port on the lid (off to the side, next to the column attachment) to empty and fill. How do you guys using kegs clean them out through that small opening? Is it even an issue?

[rad14701]

I'm actually entertaining soldering my mixing bowl onto my stockpot... A large portion of my cleanup time, which is only about 15 minutes, is spent removing gelled flour paste... And while it isn't difficult by any means it would slightly reduce setup and take down times... But I would still use flour paste to seal my copper slip joints...

[aqua vitae]

Not all Tygon is safe...

Never seen the name Tygon before and did some research. Not even qualified as food-grade in Europe so I wouldn't let it near my still.

[memetic]

I'm actually entertaining soldering my mixing bowl onto my stockpot... A large portion of my cleanup time, which is only about 15 minutes, is spent removing gelled flour paste... And while it isn't difficult by any means it would slightly reduce setup and take down times... But I would still use flour paste to seal my copper slip joints...

I am soooo glad I bought the threaded adapters! Wow how they made everything easier. It is such a pleasure to just screw my column together. I know you cannot get them in some places, but if you want me to ship you some just ask.

How would soldering a mixing bowl onto your stockpot help you? Is your mixing bowl the lid to your boiler? And your column attaches to the mixing bowl? How will you open the boiler?

[rad14701]

How would soldering a mixing bowl onto your stockpot help you? Is your mixing bowl the lid to your boiler? And your column attaches to the mixing bowl? How will you open the boiler?

http://homedistiller.org/forum/viewtopi ... =17&t=8439 which is also posted in my signature, just in case you have signature display disabled in your profile...

[memetic]

Funny, I remember reading that way back before I even ordered The Compleat Distiller. It feels like forever ago. I forgot that was your thread and rig. Nice work.

I don't know if you have trouble with your coupling and the flour paste, but mine was almost impossible to stop leaking (four joints, plus the pot to lid, and the drain to lid joint). That is why I finally just ponied up for the threaded adapters. Haven't looked back. You only have that one joint, so it probably isn't that bad. I just gave my lid to this guy to have him TIG weld the drain to the lid. Maybe I am unlucky, or just really fussy, but I have been having non-stop leak issues. I thought I had them all fixed and then pfft, I sprung another leak at the drain. The TIG weld should be the end of it.

[rad14701]

I don't know if you have trouble with your coupling and the flour paste, but mine was almost impossible to stop leaking (four joints, plus the pot to lid, and the drain to lid joint).

My flour pasted slip joints never leak...

[sterlingchap]

Are you guys aware of this material?
http://cgi.ebay.co.uk/Gasket-Silicone-R ... 3f0894ec7b
or this
http://cgi.ebay.co.uk/16-SILICONE-BAKIN ... 41586cb725
Seems you get a lot of stuff for only a little cash.
Chap

[Smokehouse Shiner]

My flour pasted slip joints never leak...

Knock on wood......

[rad14701]

My flour pasted slip joints never leak...

Knock on wood......

Those slip joints are all made to not leak liquid so I only need to insure that vapor can't sneak out... This was done by only soldering the couplings onto the top end of successively lower sections... The flour paste hardens like cement as the column heats up... It takes a wet rag to loosen the joints to a point where I can twist the components apart for cleaning...

[likkerluvver]

Are you guys aware of this material?
http://cgi.ebay.co.uk/Gasket-Silicone-R ... 3f0894ec7b
or this
http://cgi.ebay.co.uk/16-SILICONE-BAKIN ... 41586cb725
Seems you get a lot of stuff for only a little cash.
Chap

The description for the first link above includes this line:

- This silicone rubber is not suitable for use with fuel.

I'm not sure what implications that has for a boiler seal. Plain (milky, white, semi-translucent) silicone might be a better fit here since it does not contain colouring agents.

I sure wish there were definitive answers on "suitability for our needs" for this and other similar materials. They certainly would be convenient and inexpensive, SC.

[rad14701]

Are you guys aware of this material?
http://cgi.ebay.co.uk/Gasket-Silicone-R ... 3f0894ec7b
or this
http://cgi.ebay.co.uk/16-SILICONE-BAKIN ... 41586cb725
Seems you get a lot of stuff for only a little cash.
Chap

The description for the first link above includes this line:

- This silicone rubber is not suitable for use with fuel.

I'm not sure what implications that has for a boiler seal. Plain (milky, white, semi-translucent) silicone might be a better fit here since it does not contain colouring agents.

I sure wish there were definitive answers on "suitability for our needs" for this and other similar materials. They certainly would be convenient and inexpensive, SC.

I share your concerns, likkerluvver...

I would not consider that material suitable for use with any part of a still... If it was to only come into contact with liquid wash then "perhaps", but not if it would be in contact with high temperature high proof alcohol vapor or liquid... When in doubt, avoid it...

[Smokehouse Shiner]

My flour pasted slip joints never leak...

Knock on wood......

Those slip joints are all made to not leak liquid so I only need to insure that vapor can't sneak out... This was done by only soldering the couplings onto the top end of successively lower sections... The flour paste hardens like cement as the column heats up... It takes a wet rag to loosen the joints to a point where I can twist the components apart for cleaning...

I use flour pasted slip joints too Rad. Just ribbin ya.

[sterlingchap]

Are you guys aware of this material?
http://cgi.ebay.co.uk/Gasket-Silicone-R ... 3f0894ec7b
or this
http://cgi.ebay.co.uk/16-SILICONE-BAKIN ... 41586cb725
Seems you get a lot of stuff for only a little cash.
Chap

The description for the first link above includes this line:

- This silicone rubber is not suitable for use with fuel.

I'm not sure what implications that has for a boiler seal. Plain (milky, white, semi-translucent) silicone might be a better fit here since it does not contain colouring agents.

I sure wish there were definitive answers on "suitability for our needs" for this and other similar materials. They certainly would be convenient and inexpensive, SC.

"Fuel" almost certainly means petroleum-based. Such fuels are well-known to be able to get into the polymer and swell its molecular construction. But not polar solvents such as alcohol and water.

After all, silicone rubber is used as gasket material in the food and drugs industries, including systems containing alcohol. But a check with the manufactureres fo this particular sheeting might be in order for anyone trying these things out.
The second URL was for silicone sheet used specifically for food preparation (baking) so it must be OK.
The main point is that there are LOTS of solutions to our day-to-day problems if we just think a bit wider.
Chap

[sterlingchap]

BTW folks, what are the gaskets in those "tri-clover" clamps and ferrules made of?
Betcha it's silicone rubber......
Wonder if anyone actually checked if the manufacturers of THAT stuff is certified safe for still use?
Chap

[olddog]

BTW folks, what are the gaskets in those "tri-clover" clamps and ferrules made of?

PTFE gaskets are availabe for tri-clamps.
Virgin Teflon is available in small sheets on US Ebay, I buy it for sight glass seals, it's not expensive for small sheets.


OD

[sterlingchap]

BTW folks, what are the gaskets in those "tri-clover" clamps and ferrules made of?

PTFE gaskets are availabe for tri-clamps.
Virgin Teflon is available in small sheets on US Ebay, I buy it for sight glass seals, it's not expensive for small sheets.


OD

Useful input OD, it sounds like Teflon in sheet form is soft enough to seal well then; I didn't think it would be, but thanks for the education. It is a similar, low price as Silicone rubber sheet too. I think it's reasonably safe to say that Teflon presents minimal risk (as it's used all over the place in food preparation, cooking etc.)

So, if using tri-clover clamps and ferrules, Teflon is the no-guessing stuff to specify for the gasket. And they're already available! Any other type of joint including ad hoc, Teflon might also represent the simplest, effective gasket material for that too.

OD delivers.

Incidentally, I found the following pdf on tri-clover fittings. There are LOADS of different variations on the theme and it's probably well worth a read for those interested.
http://www.chicagostainless.com/graphic ... ttings.pdf" onclick="window.open(this.href);return false;" rel="nofollow

Chap

[redsoxs]

I was looking at this...

as anyone seen this before, or more to the point used the stuff?



PDF
http://www.lamberts.co.uk/profile/secti ... 35-tds.pdf" onclick="window.open(this.href);return false;" rel="nofollow

[rad14701]

That spray is merely a lubricant, not a sealant... I'd be concerned that due to the fact that is doesn't really bond to anything that it would end up in your boiler charge even if it didn't pass over into your spirits... Teflon makes a great lubricant but I don't see a safe place or practical use for it on a still...

[redsoxs]

That spray is merely a lubricant, not a sealant... I'd be concerned that due to the fact that is doesn't really bond to anything that it would end up in your boiler charge even if it didn't pass over into your spirits... Teflon makes a great lubricant but I don't see a safe place or practical use for it on a still...

Thank for the explanation, i wasn't to sure if it was just a lubricant or both.

[rad14701]

That spray is merely a lubricant, not a sealant... I'd be concerned that due to the fact that is doesn't really bond to anything that it would end up in your boiler charge even if it didn't pass over into your spirits... Teflon makes a great lubricant but I don't see a safe place or practical use for it on a still...

Thank for the explanation, i wasn't to sure if it was just a lubricant or both.

Reading the product information pretty much tells the tale... One of the propellant components is alcohol and if alcohol is an application component it will also be a removal component... There are no other binding agents and if there were we would need to be concerned if they were alcohol tolerant as well...

[mash rookie]

Virgin Teflon, Already had sex Teflon ??? Yes we all want the virgin.

I learned many years ago the virgin would stand up to very high temperatures. We would shape 1600 degree glass with it. Non Virgin would burn and smoke giving off noxious fumes.

Virgin Teflon is available at most plastic stores in sheet, tube etc. Teflon tape is available at the hardware store. I think minimal use of course is key.

My column slips down over a six inch stainless pipe welded to my keg lid. I use about 10 wraps of Teflon tape at the base of the pipe then slide the column on. The weight of the column easily creates a seal. Even with minimal pressures any alcohol exposed to the Teflon tape is pushed downward and trapped in this six inch overlap area.

I plan on not using seals on my flute sight windows. I will machine the surface perfect flat on the fittings and tighten my glass directly to it. With the minimal pressures in a column they should seal well.

This could be easily done without a lathe as well. Using a larger piece of glass and abrasive compound the fitting could be lap finished flat by hand before installing or the sight glass and surface could be lapped together like engine valves were hand lapped in the old days.

I have 1 ½ “ copper trap adapters for my sight windows. I will use and old style rubber trap gaskets on the outside of the glass to establish even pressure form the nut to the glass so the two surfaces are held tightly together.

[myles]

You can get solid PTFE sheets from several sources. I bought a sheet to make sight glass gaskets but it is harder than I expected. Potentially more usefull is reuseable catering PTFE sheet. Either in the form of tray liners or possibly more dureable is the oven liner like this:
http://www.nisbets.co.uk/products/produ ... Code=CE172

[likkerluvver]

Hey Myles,

The price is right but the description says:
PTFE-coated non-stick liners to make cleaning ovens easier.

Since the core of the sheet would be exposed to the alcohol in most applications, I wonder what the core of the sheet is made from?

[mann_ox]

I use a PTFE baking sheet brought from the supermarket
works great for sealing the boiler to column
cut out the ring shape with sizzors
and sharpened the end of a piece of tube to punch holes where the bolts go through

I've used it for 10 runs now and still looks identical to when i brought it ,
hard wearing and compresses well ( had a bit of distortion in the metal when i welded the column to flange )

[likkerluvver]

Many of these oven liner sheets are "Teflon-coated", and do not state the composition of the base. This would work well if it is solid teflon:
http://www.amazon.com/LARGE-Teflon-Oven ... 842&sr=8-5" onclick="window.open(this.href);return false;" rel="nofollow

These state that they are teflon coated:
http://www.amazon.com/Regency-Inch-Spil ... 842&sr=8-7" onclick="window.open(this.href);return false;" rel="nofollow
http://www.amazon.com/Chefs-Planet-23-I ... 42&sr=8-11" onclick="window.open(this.href);return false;" rel="nofollow

This states that it is teflon coated with fibreglass substrate:
http://www.amazon.com/Johnson-Rose-Bake ... 92&sr=8-19" onclick="window.open(this.href);return false;" rel="nofollow

Not cheap... but these look good if you (use a lot or) have others to share it:
http://www.amazon.com/CS-Hyde-Virgin-Ad ... =8-3-fkmr2" onclick="window.open(this.href);return false;" rel="nofollow
http://www.amazon.com/CS-Hyde-Virgin-Ad ... =8-1-fkmr2" onclick="window.open(this.href);return false;" rel="nofollow

[rad14701]

likkerluvver, we have some of that sheeting and it is paper thin... It wouldn't work well for sealing anything other than machined surfaces... It sure holds up to oven heat though...