Wood versus metal bung on column?

[Kismet]

I just finished building my column but I'm missing one critical component. At the top of my still, I had a natural, gum rubber bung but after the first run, noticed a distinct rubber taste in my spirit. I thought this might happen based on what I've read here in the forums so I'm looking to replace it with a wood bung or copper bung.

Copper will be more difficult for me fabricate so I'm aiming for wood but I'm concerned that wood may also add unwanted flavors to my spirit. Does anyone here use a wood bung at the top of their column? How long has it lasted before it starts to deteriorate?
Thanks to everyone who has posted in these forums as it's been the single most useful learning resource for me.

[olddog]

If it's a reflux still it should not be capped anyway, if it's a potstill it should not have a cap, it should be sealed with a soldered copper fitting.

[ScottishBoy]

A little more detail about you still might let us suggest a few things

[rad14701]

I agree with ScottishBoy in that knowing more about your still would be helpful... A bung may or may not be the best solution, whether rubber, wood, or perhaps a copper cap would work better as olddog mentioned... A picture would be helpful...

[kiwistiller]

I suspect it is a CM style with a thermo and a bung at the top. if this is the case I'd suggest looking into cork / ptfe options.

[Kismet]

Kiwistiller is correct, it's a CM style reflux. I'm really just trying to practice my soldering skills and thought this design would be the easiest to start with. I had chosen a bung instead of a cap because that's what I had seen looking at some of the columns on milehighdistilling.com and I was hoping a bung would be a good pressure release value should something go terribly wrong. I looks like I should just use a cap instead though.
I'll post photos of the design as soon as I can borrow someone's camera.
Thanks guys

[Dnderhead]

Id suggest a cap,, drill a hole,, then place a marble over the hole. if you have about 3/8 hole and the marble is 1/2 it should sit there.

[airhill]

If its a CM Dnder he doesn't need a pressure release but he does need the thermo in the top.(pic would be good)

Wooden bung or cork with a hole drilled should do it, just make sure the wood isn't toxic and after you have inserted the thermo put it in some water to swell the wood to see if it leaks.

[Dnderhead]

all right so "stick a cork in it"

[airhill]

OK

[Dnderhead]

if you drilled the hole small,, drove a punch threw (the appropriate size) backing it up with a pipe,so you had a "flair"Id thank the cork whould seat better.

[Barney Fife]

I've used wood plugs with my thermometers before; works great. The wood will swell tightly shut as soon as the vapors hit it. Before making the bung/plug, dry the wood for a few hours in an oven(toaster oven will work) at 200F, so to dry it completely. Then shape it, drill it, whatever, put it in place, and it will swell tightly in place.

[rednose]

I'd use something like this, a selfmade overpressure valve in copper or SS.

You need to be able to blow through easily and it'll work fine.

[ScottishBoy]

Try a cap with a hole in it, then place a penny over it. If pressure starts to build, the penny will start to dance giving you a few precious minutes to drop your heat or react as you see fit. Bungs and release valves tend to go all at once. If there is a spot on your still that has a lower relative strength than the release or bung, then it will rupture first.

Just something to keep in mind.

[Dnderhead]

we have discussed it and he needs a place for a thermometer also,, a cap with a hole with a cork will due both.
and if you want a "boil over alarm" you need it down near the bottom of the column, at the top it's to late.

[ScottishBoy]

This what happens when you are at work and decide to chime in...

Yeah, the dry wooden thermo holder sounds good.

I might have to look up the boil over thingy. Sounds interesting.

SB

[Dnderhead]

I feel of the column, when it gits hot about 1/2 way up it's time to turn the heat down, a simple thermostat with a buzzer/light whould do. a bimetal disk ? sort of forewarning "standby" thing are about to happen!

[Kismet]

wow! These are all such great tips! I ended building a cap and simply using the old flour-water mix, but now I don't have somewhere to put the thermometer (cap is too to thin, therm just flops around in the hole without any support).
I'm tempted to try all of these methods - wood or cork bung, penny on cap, marble in hole technique. These are all such great ideas. Thanks everyone. Now I know why my father had such fun doing this when I was a kid.

[Dnderhead]

""cap is too to thin,""
that is why I suggested drilling the hole small. then driving a punch threw to flair it. that whould give more support for cork.
(thank bullet hole)

[airhill]

Hello! its a CM, why does it need a pressure release any more than a potstill would?

[Dnderhead]

he needs a way to hold the thermometer,

[airhill]

The 'rubber' bung is likely to be a synthetic, able to handle the heat but not the higher volatiles, a quick and dirty fix until an alternative is found would be to tightly wrap the bung in wide ptfe tape. A pic would be useful though.