Onion build for £50

[Oroku saki]

Hi there everybody,
So I’ve been thinking and would love to hear your feedback . So I’ve come across a copper pitcher/jug/vase (see bottom picture) that is a foot in diameter at the widest point and got thinking that this would make a perfect onion cap attachment for my modular still! What I’m planning on doing is putting a 4” or 6” triclamp ferrule on the bottom and then take a spout from a old copper teapot as the goose neck (bend the end where it goes to horizontal back around and chop the end off) that would come straight out the top of the vase bulb without the top part on it (cut either just above or below that smaller bulb on the neck) where I’ll attach another appropriately sized triclamp ferrule or KF ferrule. What you guys think? And has anyone ever done this? I’ve been looking at a lot of old copper stuff like pitchers, vases, couldrons, teapots etc and there’s a lot of good stuff there that can be utilised , it’s good thick hand beaten pure copper so I can’t see a problem with it. I’ll remove any solder already on it as well as any brass if any. This will be going on a 50L keg with heating elements in it. Not sure if this would be too big but while over in Croatia I saw some with enormous onion caps and as I’m interested in brandy then I’d love a nice onion cap. Also if you check out how much these things run as far as cost, your looking around £500 for one and this thing is £15 so by the time I’ve added ferrules, thermowell for probe etc. it’ll cost me 50 bucks to get done and I’ll have a pure copper triclamp onion with thermometer

[The Baker]

I don't think a probe is important at all.
If you leave that out it will simplify your work a lot.

BTW that is a good idea, I will look out for these.

Geoff

[Oroku saki]

Ye I was thinking of putting it on a PID controller that’s why I was thinking of putting a Thermowell in. But ye check out couldrons etc they are perfect and I’m sure originally these would of been used or at least made by the same people as they were in use and everywhere

[The Baker]

Those who know will tell you to avoid PID.

Geoff

[MartinCash]

What are you hoping to achieve with the PID controller? I mean, what will you be using it for? Please wait to use one until you understand how they work and what they do, and how it may help or hinder what you're trying to do.

[Oroku saki]

Well I was either going to use a PID controller or just a simple controller and manually turn it up a little a time when it starts slowing down, I’m sure the PID controller with the thermo couple placed at the point of the vapour Path entering the goose/swan neck would even out the run in the hearts section.

[Oroku saki]

BTW I have several PID controllers for other things and understand how they work. So instead of my elements being on 100% and switching off and on to keep the temp constant, the PID will adjust the input and after a short while will “learn” what it needs to do to keep it at a, pretty much, constant temp. What would you guys say are the draw backs from using these to control the heating elements? I’ve always used propane or wood over in Croatia but really would like to go electric with my new build. What would you say is the best? SCR controller?

[Setsumi]

if you can set the PID to power mode like PWM it will work. you want to regulate the rate of boil not temprature. a SCR is much better and cheaper.

[Oroku saki]

I realise with a PID I will have to manually creep it up in temp periodically but have seen George over at barley and hops using one with good effect and as I have a few lying around thought it would be worth a try, also why wouldn’t you want a thermometer to read head temps? Surely this is handy to have on any still?

[Oroku saki]

If you guys let me know what are the drawbacks from using a PID that would be great but I don’t really want to get into the weeds with that when this post was about the DIY onion and teapot etc.

[MartinCash]

It will not work the way you think, and George is in the business of selling PIDs and PID stills. Many of his refugees arrive here asking why their stills do not work.

You want to control the heat input, not the temperature.

[Oroku saki]

So what do you suggest? SRC or PWM? Also PID’s would control the input heat as it’s controlling the percentage of power going to the element and adjusting based on time and temp. Also I’ve nothing to lose here, If it doesn’t work as desired then I can just slap on a thermometer instead.

[Oroku saki]

I’ll give you guys an update once I’ve got the ferrules here and fitted. This onion will be beautiful once done and for a steal. I wonder if anyone else has done this?

[Oroku saki]

But any input on size ratios between cap/head and boiler size would be appreciated

[Yummyrum]

I think you will make a very nice looking pot still head

A PID will not work as you imagine . Yes you need a Power controller . George has some pretty flawed perceptions of distilling but sells it as gospel .

Apart from PIDs not working based on temp , unless it has a power cycle period of about one second or less , the on/off power cycling stuffs up the distillation process .

Anyway , thermometers and temp sensors are absolutely useless in a Pot still so don’t destroy tour potentially awesome onion head bu sticking a useless thermo port in it

[Oroku saki]

Thanks for your reply that’s the sort of constructive stuff I’m looking for. I understand what you mean when I think about it none of the stills in Croatia had any, you see my background is in chemical lab set ups and my still I have is a column/reflux still where head temps are needed. So I totally agree. I wasn’t going to stick it right in the middle like the ones sold, I was going to stick it in the teapot spout but I’ll leave it out and get her sorted out. There are tons of these for sale all over the place and can be had for a steal. I also have found plenty of other items that can be utilised such as tapered cylindrical vases for reducers and copper pots as sections for 4” (or as big as anyone would want at our scale) bubble plates. But as for onions there are many. I found an old research paper a while ago looking at the impact of the shape of head and goose/swan neck on the final product, they compared 5 shapes 2 of which had onions and analysed the compounds present in the resulting distillate. It was quite interesting and the results a bit surprising. I’ll dig it out and post it somewhere on here so everyone can have a read.

[Chauncey]

We gotta make a truth about PID thread


Subtext

Power control is what you need not temp control.

[MartinCash]

Hi Oroku saki,

In a reflux column, you want to maintain constant power input, with no fluctuations, until ABV starts to increase, at which point you can start to increase the reflux ratio in order to maintain purity and keep the tails away. Ways to increase the reflux ratio include reducing the product collection rate, or increasing the flow of coolant through a dephlegmator. They do not include reducing power to the boiler, as this does nothing for the reflux ratio.

In fact, in a standard run for me, I only vary power to the boiler on very defined moments: start of boil, after fores, and after heads. A decent reflux still almost runs itself and needs little fiddling with power. You need to control cooling and take-off rate, not power.

Does that make sense?

[Oroku saki]

Yes of course, I was simply thinking at the start to get up to temp quickly to have more power And to be able to back off a little for the run, I will be running my still in a pot still configuration this year, I want to see the difference in flavour profile between my column set up and doing low wine runs then back in for spirit runs anyway so I see now a PID is a shit idea as it’s a moving target etc. Anyway thanks for your advice everyone and I’ll keep you guys updated on the onion. Just to put it perspective the narrow part of the neck is 65mm or around 2.5” and the diameter at the widest part is a foot across! Do you guys think this is suitable for a 50L boiler or too big? Is there an optimum size ratio like a thumper should be around 1/3 of the size of the boiler is there a correct size the onion should be?

[6 Row Joe]

Too bad this thread got sidetracked talking about pid controllers. I was looking forward to finding out more bout onion heads. I bought one from India. It got stalled getting into the country and I got a scary note from the postal service about distilling being illegal in the US. I was alarmed enough I disposed of it when it arrived.

[Chauncey]

I dont know if they add anything but looks on a small scale

[Oroku saki]

I’m sure the vapour pressure difference going from a narrow neck and widening to such an extent must force the distillate to precipitate and will also increase the surface area in contact with copper too.

[Oroku saki]

6 row joe, I’ll dig out that research paper that is an in depth analysis of the impact of the shape of the swan/goose neck and onion (with/without) on the resulting distillate (brandy) and the compounds present as well as comparative analysis. It’s worth a read with some unexpected results , well as far as I thought anyway, I’ll post it somewhere on here and drop the link here

[Oroku saki]

Here you go guys, https://homedistiller.org/forum/viewtop ... =1&t=82057

[Oroku saki]

I’ve also decided to scrap the teapot spout for this particular build due to the size of the neck and instead will attach a 2 1/2” / 2” triclamp ferrule to the top so I can attach a 180* , 90* or 90*+ 45* tri clamp fitting to go to my condenser or gin basket (if I decide using one in the future)

[6 Row Joe]

Here you go guys, https://homedistiller.org/forum/viewtop ... =1&t=82057

Thanks, I'll study a bit.

[Sailman]

I am one of Georgia's refugees. I too like the Simplicity and the ease of using a PID. Sadly that was not the case. I didn't even get through my vinegar run with the PID. The problem that I was having was that it kept chasing temperature it would rise too high and then fall too low. I contacted George on several occasions and spoke with him in length and both of us could not figure this out. I eventually went with a pwm. The PID that I was using was a mypin ta4. The only suggestion that George had for me was to buy a inkbird PID and try that. And before you ask yes I gave it time to balance the column. You stated that you already have a PID so try that you may have better results than me and other people here. I do like your idea of using the bottom of a picture for an onion so I guess I'll be off to the flea market this weekend

[Chauncey]

Im pretty sure that paper doesnt relate to tiny stills. Compared to the study even our size limit is a tiny still .

[Oroku saki]

I’m sure you’ll find that lyne arm angle and position do make a difference on the resulting distillate, not to mention a pressure drop due to the neck going from 4” to 12” as well as an increase in copper surface area in contact with the vapour. Don’t forget that these concepts make a different in a lab setting where glassware and boiling flasks of 1 to 5L are being used so with a 50L boiler and 12” onion it’ll will make a difference and hey, if it doesn’t I’d like to know why and learn from it anyway! As I am making my still completely modular I can do several runs with several configurations and document the results to share with the community. But I think your reasoning is flawed here Chauncey, That paper was only using a 140L pot still with a charge of 100L of low wines (made up of 70L low wines and 30L heads/tails mix! This is hardly a monster 1000 gallon still we are talking about here and still within the sizes people use on this forum (correct me if the limit is smaller I can’t remember at the moment) and all that info is valuable. Plus we all know that if you place a Big long column on your boiler the resulting distillate will be of a higher proof as well as a little less on flavour due to the distillate being evaporated and condensed several times (reflux) before making it to the condenser. An onion, if nothing else, would also have this effect due to the large surface area for the distillate to condense on, also if you have a swan neck coming straight out the top as compared to 90 or less the distillate has to make it all the way to the top (acting like a column so more reflux). At 90* you will have less reflux and would act more like a retort. And these principles carry all the way down to micro distillation in the lab that I have several sets of, the boiling flasks are down to 25ml and the column is 5” and 8mm ID, or can be set up for direct or short path distillation. We are talking about a 50L boiler with a 12” diameter onion here and all those principles will apply I am sure. Of course without packing the amount of reflux will be less than a fully packed factioning set up but as that paper suggests there is a difference in the resulting spirit. Sorry to hear about that sail man, when I use my PID’s in other applications they normally over shoot a little to begin with then back off as they “learn” how much power it needs to input and for how long to keep it where you want it but it sounds like a nightmare you had there buddy, did you put thermo grease on the tip of your probe inside the thermowell? Or was it a gland that the actual probe went into? If using a thermowell then use a little thermal grease to get an accurate reading. But honestly I might try it some time with a column set up but they would be completely useless in a pot still set up. And hopefully thats the last we hear about bloody PID’s in this discussion as it is about onion caps, building them for a fraction of what you can buy one for (like £500 compared to under £40 at the moment) and their impact on the resulting spirit. Sorry for the long winded post but hey

[Oroku saki]

So back to the onion, I know this has been discussed on this forum before but has anyone found a decent alternative to stay clean flux in the U.K. for silver bearing solder SS to copper or SS to SS? I’ve been hunting around and found some called A8 liquid flux for stainless steel, it’s only a fiver for 125ml of the stuff so going to get some and try it out because although I have had success with Harris stay clean and stay Brite kit, it cost me £28 for like a tiny bottle and a couple of feet of the stuff so looking for a viable alternative if anyone can help? This is the link to the stuff I’m going to order https://soldersandfluxes.co.uk/p584/A8- ... Steel.html
The other thing I’ve read is that phosphoric acid seems to be the base of hydrochloric acid isn’t at about 75% range, now I just so happen to have a small bottle of phosphoric acid as it is used as a food grade PH down in the hydroponics world. Does anyone know if it will work on its own or shall I just try this A8 stuff?