New DIY reflux still- questions before 1st run

[kierent]

Hi all
I've done a number of neutral spirit runs with a friend's borrowed still (unsure of brand but it had about a 20L boiler and ran pretty well) and thought I'd convert my BIAB setup to a dual purpose rig- for brewing and distilling.

So I have a 40L Crown urn with concealed element and bought a copper mast from Kegland, then cut a hole in a stainless bowl for the dome with a stainless ring and clips to aid sealing (bit of help from my dad for this bit). I've also split a food grade 8mm gas line that sits on the top of the urn lip so it seals.

I know it runs with water boiling inside and doesn't leak, so now I've got a 25L TPW bubbling away downstairs for it's maiden run.

Couple of questions:
1. First obvious question- does anyone see any obvious issues or problems with the setup?
2. Is it an issue not having a way to measure the temp of the liquid inside? The still I borrowed didn't have anything like that but as I've been reading the last couple of days, it seems most people suggest to keep an eye on the internal temp as well as the temp in the top of the mast.
3. Along those lines, what temp should I set my urn to for the run? Do I just turn it up to full and let the internal temp climb as it heats up, then make my cuts accordingly?
4. Does it matter which of the hose fittings on the top of the mast are in and out? I'm assuming it will circulate no matter which way the water flows, but maybe there's a better way? There aren't any markings on either pipe that I can see to say if one's 'In' and one's 'Out'.
5. Anything else I'm missing?

Thanks in anticipation. Hopefully someone with more experience than me will chime in, but either way I'll post my progress to this thread.

[RC Al]

Using a temp dial wont work fantasticly, it will be cutting the power in and out constantly, stills run much better with a constant setting - ie voltage control not temp

A temp probe will help dramatically (i'll go as far to say a necessity for a newbie), looks like theres a spot for a temp probe next to the outlet, you may be able to slip a temp probe down the opening at top otherwise.

Your cooling hookup shouldnt matter too much, but I would be trying to put the inlet on the one that runs through the middle of the cooling coil

Someone has mentioned with these that the product will come out pretty hot, getting it a bit cooler than 70+ degrees might be good for safety

The 8mm gas line most likely wont be the right stuff to cope with high % alc vapour - food grade is a good start, but that dosent imply solvent proof, PTFE or 100% silicon is recomended

Your still type is a Liquid Management Boka (LM, Boka Bob), have a search on running this type of still

Oh and welcome, no doubt this will get moved to the welcome centre :)

[Sam.]

Correct, welcome here mate :handgestures-thumbupleft:

[warramungas]

I had a birko urn and I cant see your photos. Have you got a good seal around the top between the urn and the bowl. That was the biggest problem I had with mine. Leaking ethanol vapor is bad.

[kierent]

Thanks all for the input, and for moving the thread.

I have a good seal, but I'll look into some 100% silicone tubing for the seal. Also I'll look at a Boka Bob still, thanks for the heads up there.

[woodduck]

Give these a read,

viewtopic.php?f=57&t=11077

viewtopic.php?f=57&t=3541

Get rid of the gas hose. Food grade doesn't mean alcohol proof. Silicon, epdm or natural cork are the best. I don't love the lid how it is but if you check it every run to ensure it's not leacking it should be ok?

I'm guessing the hole in the side near the tap is for a thermometer. Make sure that is sealed with good quality thread tape too so it doesn't leak alc vapor.

I don't love the brass either. Would be good idea to look into getting it pickled (coated in lead free solder)

It won't matter which fitting the hose goes on, thats just a coil in the top.

I would look into getting/ making a little liebig condencer for the output to cool the alcahol down so you get good % readings with your alcometer, it will make life alot easier.

Good luck mate, hope she goes alright for ya :handgestures-thumbupleft:

[kierent]

Thanks woodduck, appreciate your help. I've read those threads too, very helpful.

Ok, so I'm getting rid of the beer line, but having trouble finding 100% silicone. You mentioned EPDM though, and I found this on ebay: https://www.ebay.com.au/itm/EPDM-Type-P-D-E-I-seal-strip-2M-Auto-car-door-window-rubber-foam-self-adhesive/262141919688?hash=item3d08e041c8:m:mk2sy6eLVQoUEX3qE3uBJWw

Is all EPDM equal? This seems cheap and is for an automotive application, but if it's the right product it would definitely be the best way to achieve the seal I'm after. Otherwise, can anyone recommend where I might get 100% silicone?

A couple of people have mentioned the hole for the thermometer, yes, at the top of the condenser near the tap is a hole and that's where I'll put my thermometer to measure condenser temps when determining cuts. My original question about temp though was to do with the temp of the liquid in my boiler. I can't see a good way to measure this temp without compromising the seal (eg if I dropped a probe into my boiling liquid from the top), but I have purchased a voltage controller so I'll just experiment with the required voltage to get a good fast drip coming out of my condenser tube.

Woodduck, you mentioned the brass, that was just what came with the product from keg king. I'll look into getting that pickled.

So I think when I can find a good product to seal the top of the still I'll be good to go, at least for now. My tpw is sitting at 3 degrees for now to clear up anyway, so it's not a huge rush.

Feel free to add any advice!

[woodduck]

Not sure about that seal your looking at, don't know anything about them sorry. I would try chase some silicon hose but I'm not sure where to get it sorry. Clark rubber maybe?

Don't worry about the temp of the wash while boiling as that will change as the alcohol is depleted. The temp gauge in the top is really only a guide as well. It's more to show you a jump in temp so you have an idea when tails are coming. Don't try and do cuts from a thermometer, won't work, follow the cuts guide in the newbies corner. Use your alcometer to determine when tails are coming, the % will drop. It will also tell you if you've got enough reflux and if your take off speed is correct to get a clean product.

[kierent]

Found a good EPDM rubber foam seal in bunnings, so I'll use that. I'm going to try a water run tonight to make sure everything's clean and hopefully do my TPW next week once my voltage controller and copper scrubbing pads have arrived.

Once more question- I've read mentions of stripping runs before spirit runs. That's mainly for pot stills isn't it, rather than reflux stills?

[bluc]

For neutral pretty much all stills benifit from 2 runs...

[db1979]

Found a good EPDM rubber foam seal in bunnings, so I'll use that. I'm going to try a water run tonight to make sure everything's clean and hopefully do my TPW next week once my voltage controller and copper scrubbing pads have arrived.

Once more question- I've read mentions of stripping runs before spirit runs. That's mainly for pot stills isn't it, rather than reflux stills?

I don't know if you should trust an epdm rubber that isn't food grade. Like woodduck said, you should try for silicone tubing. Try home brew shops or even ebay will get you what you need.

What's your location? Some members might be able to give you a specific shop where you could get what you need.

[db1979]

My first boiler was also made with a stainless mixing bowl for a lid but I made what is known as an "everlasting PTFE gasket". Google it. Worked no worries for many many runs and is still going (I don't use that boiler anymore but there's nothing wrong with the gasket). Simply need cardboard and plumbers tape (Teflon). I made mine from a weetbix box (and I made weetbix vodka out of the weetbix :D)

I made two over the time that I was using the boiler and only because I made the first so that it was just the right size, but it shrank with use. So the second I made about 1/2" oversize on diameter and it's worked great.

[kierent]

Thanks for that, I'll have a go at that seal.

I'm doing my TPW run now and it seems to be going well. Bloody slow though! Started about 10am thismorning and it seemed to be doing well sitting on around 79 deg C but it got real slow thisafternoon. So far I've collected probably 2L and I've had to let it rise to around 85 deg to keep it coming. It's still producing around 80% and smells and tastes clean (although I'm aware I may not be the best judge as I've only done a handful of neutral runs).

I'll give it a couple more hours but probably hit the hay after that. If I treated this as a stripping run, I'd just dilute my collected spirits down to 40% and go again right?

[kierent]

Meant to say in that last post, I was expecting a lot more out of this run...

I made a 25L tpw that I measured to be around 20% alc vol. By my calculations, that's around 5L of alcohol. Now I don't expect to get 5L out of a run because it's not possibly to extract every bit of ethanol, but I would have thought I'd get more than a couple of litres? Am I wrong in assuming that?

Either I've mis-calculated my wash strength, or the still I've bought/made isn't amazing. I'm willing to accept that I might have made errors, but really all I've had to do is seal it up. Maybe the alcoengine refulx still is crap?

Any opinions/suggestions?

[RC Al]

Did you base your figures from SG readings?
Alcohol meters only work accurately in water/alcohol mix, a wkgash has lots of stuff in it that throws readings off

I usually get 11% give or take on the standard recipe

[kierent]

Apologies for so many posts/questions in one go... but i'm having a bit of a WTF moment here. In short, I've turned the power/temp up on my voltage controller and the temp at the top has dropped considerably??? Plus my % has gone up

I'm using a voltage controller as suggested earlier so I can keep the boiler at a constant gentle boil rather than just having the 2400W element flat out. So I've had it wound back to about 100-110V for most of this run. That's what seemed to get the best equilibrium when I started and got it up to 78.5C. I found that if I boosted it even a few volts, the temp would climb a bit so I thought that was a good level to keep it.

As the run has come towards what I thought was the end, the temp in my probe thermometer (up the top near the tap) had climbed up to above 85C, and when it got to 91 I thought I'd call it quits. It still tasted and smelt good, and was coming out around 72% so I was happy enough to keep that stuff, at least give it a day and see how it smelt. I had mentioned too that all afternoon it's been dripping very slowly, to the point where I turned the tap off and replaced the 0.6mm valve with the 1.0mm valve.

So my WTF moment- I figured seeing I was done, I'd turn it up to the full 240V and see what happened. As soo as I turned it up, it started boiling more vigorously but the temp DROPPED, from 92C back down to a constant 80.4C. I'm sitting here writing this post and it's been sitting there the whole time, and dripping out much quicker now. Not a constant stream, maybe 2-3 drips per second. This is what I'd been getting earlier. It's also coming out at 86.5% now.

So if what I'm collecting now is reading at a good temp (80ish) and a good %, should I keep going? It doesn't smell like wet cardboard. If anything, it tastes slightly sweet, which I guess isn't so desirable for a neutral. But I'm convinced there's more ethanol in this mix than what I've got out of it so far.

[kierent]

Did you base your figures from SG readings?
Alcohol meters only work accurately in water/alcohol mix, a wkgash has lots of stuff in it that throws readings off

I usually get 11% give or take on the standard recipe

I use a brewing hydrometer for my wash readings. From memory, i had and OG of 1.088 and a FG of 0.920. I haven't had this sort of efficiency before, and from memory my TPW doesn't normally start that high. But I was going for 5kg sugar so I put in 2x2kg bags and guessed half of the last 2kg bag so I might have been a little over.

[RC Al]

More power means more reflux, you put more vapor up the column, which is refluxing back down

13% on my hydro on those numbers

[kierent]

Yeah, I figured more vapour up the still would explain the increase in output, but I didn't get why it would read hotter at a slower boil and then cool down with a more vigorous boil.

Not sure how you're getting 13%... I have always used https://www.brewersfriend.com/abv-calculator/ for my calculations (been brewing AG beer for over a decade) and it gives me 22.05%. As I said though, that seemed high to me so I'm thinking maybe my final reading was wrong somehow. I may have forgotten to allow for it being at 30deg rather than the 20deg it's calibrated at, but that only takes it down to 21.79%

[RC Al]

oopps, i read it as 0.992 not 0.920 maybe your mistake too?

Sounds like you would be able to run a bit more power than you were if you can up the cooling flow? did you change the coolant rate when you upped the power?