The Cletus Modular 4” Bubbler Build

[Cletus_Spuckler]

Hi All. Im a new member / long time reader. This is my second still build (the first being a 2” boka). This time I’m going to document it on here as I go. This way I can engage with my fellow home distillers, get ideas for better ways of doing things; and maybe even contribute a few ideas or advice of my own back to the community.

The purpose of the new still is to produce vodka or gin much faster than what it currently takes me, whilst maintaining or maybe even improving on the quality of the neutral I am already making. Once the still is fully complete and I get used to running it; I’ll start experimenting with whiskey and rum production.

This will be a staged build, ultimately resulting with your typical modular still; consisting of, 6 x 4” bubble cap tees, a packed section and shotgun reflux and product condensers. Stage 1 will result with a 1.5m packed 4” boka which I can complete fairly quickly. This will enable me to continue using the still through the (lengthy) build process.

The approach is to first build the 2”- 4” keg adapter, a 1.5m x 4” column, a single 4” bubble cap plate, a new 4” LM slant plate and to re-purpose my existing boka condenser. At completion of this stage, I will have an operational 4"boka. As I then feel inclined, I will chop 170mm sections off the column and turn these into bubble tees. Once I have six tee’s plus a small packed section; I will then build the shotguns, elbows and other bits and pieces needed to complete the final build. I suspect start to finish will be about one year!

I’ve already made a start, so I’ll chuck in some photos and words to get you up to speed with where I’m at! Hopefully you'll still be reading this topic at the other side of the build!


Cletus

[Cletus_Spuckler]

I'm going to document the steps I've gone/going to go through in my build. This is so that I can get feedback on better ways of doing things and maybe help other people as well. What I am doing is my interpretation of the techniques and designs learned from this site.

Though I'd start with my easy flanges!

Flange Jig

My flanges are hammered out in a jig, thickened with a ring of flattened ¼” tube (can’t get solid grounding wire here), brazed together, then ground down to the correct size and shape.
I decided to build a jig to make easy flange construction, well, easier – and more consistent. I took the idea from another member (YHD) who made his much nicer one entirely out of plastic chopping boards viewtopic.php?f=17&t=57708.

My jig:

• The total length of the jig is about 157mm. Calculated as: 145mm (final finished section length) + 12.5mm (enough extra for the second flange).
• There is a removable 12.5mm spacer within the jig, which I remove after flaring the first flange.

• I cut a 170mm section of 4” tube for each section, which allows it to protrude 12.5mm beyond the flange face plate.
• Everything is measured and square

• I reused the centre pieces of wood left over from cutting the holes, to try and help prevent the insides of the tube getting bashed in. It helped a little, but not much. (I found a better approach is to just not anneal the tube. They tube keeps shape better that way).

• I used plastic for the face plate as I didn’t want to destroy my expensive hole saw by cutting steel. Plastic seems to hold up pretty well despite being repeatedly bashed with a hammer.

[fizzix]

Nice to see an artisan's work. You home builders do some impressive work.
{I soldered a hose spigot once....whoopee}

[Cletus_Spuckler]

Thanks fizzix. I'm a pencil pusher, by trade so Ive had to learn a lot doing this stuff! Although I've got a tradesman friend who has lent an extra hand too many times to count!

Hammering Flanges

The way I do it can be explained like this:

• I don’t anneal the tube, so as to avoid it collapsing in at the base.
• First I draw a mark on the tube to keep track of when you complete a full pass, so as to ensure you hammer the tube at an even rate. I also draw a line where I want the final inside edge of the flange.

• I get started by gently flaring the outer end. I do this by using a firm but gentle down and outward motion, at the end of the tube.
• Once I have flared it a little, I then move to define a crease at where I want the inside base of the flange to be. Again, using a gentle yet firm, down and outwards motion. Once I’ve gone all the way round, I will then do two more passes to make sure that the tube has been hit evenly.

• From here it’s just about slowly and consistently working around the tube, pushing the edge out slightly farther with each full pass.
• I avoid the flat side of the hammer until the tube is flared to about 85°. When I do use it, I am careful to maintain a firm outwards motion, as I have found that it is at this stage that you risk caving in the base of the tube wall. Again, not annealing the tube helps.

• Once hammered flat in the jig, I then take it out, stand it up on a flat hard surface and hammer down from the top a few times.
• Finally, I stand it up and measure it from two sides (12:00 and 3:00). This part of the process takes me 20 minutes.

This was the first one I did on this build. I annealed this one and as you can see, the tube bent in. That didn't happen for the ones that i didn't anneal.

[Swedish Pride]

Lovely work lad, very thoughtout and measured approach.

If you want to save a few bucks on a 4"to 2" reducer you an always just solder a 2" ferrule in to a piece of copper sheet and just solder that to the bottom of the 4".
Saves a buck and some height if that is of consern

[Cletus_Spuckler]

Thanks SP, I like the challenge of doing the best work I can. Sometimes it's cheaper and quicker to put a lot of thought and preparation in beforehand. Ill have a think about what you said regarding reducers. I've made my first one already which I'm going to show soon. I always want new ideas for how to do things simpler.

Rings

I’m not sure if this is necessary, but I always like to make my flanges thicker and stronger. For my last still, I used the “melt solder into a hose clamp mold” method; but I now prefer the “braze on a ring of flattened ¼” tube” method (we don’t have grounding wire here). I think it uses less solder and is less likely to get destroyed if you put too much heat on it. I learned how from this post: http://aussiedistiller.com.au/viewtopic.php?t=76I" onclick="window.open(this.href);return false;" rel="nofollow

I found the biggest trick is getting the rings just the right size so that once flattened. If they are too loose, you use too much solder to fill the gap between the ring and the tube; and if the rings are too tight, they might not sit flush against the flare (due to a potential for a slight curved fillet at the point where the flare turns out from the tube wall). I always seemed to make mine to tight, and had to file them out from the inside. Next time I make one, I will wrap the rings as tight as I can around the tube, then offset the cutting mark by 10mm, making it wider.

Before you join the ends of the ring, don’t forget to paint on a little bit of whiteout / liquid paper so that the solder doesn’t run everywhere! I wish I learned the whiteout trick a few years ago. Would have saved a lot of cleanup).

Once I have two rings flattened and sized correctly, I clean both them and the first completed flare (as it ain't going to get easier to clean than at this point).

[Cletus_Spuckler]

Finally, I slide the rings over the section I’m working on, remove the spacer from my jig and start the second flare. Note, I have a groove routed out in the jig for the rings and flare to sit within.

[Cletus_Spuckler]

Assembly

I forgot to take photos of the soldering, however the four key things I learned were:

1. Put liquid paper everywhere you don’t want need solder to run to. Especially on the base of the flange and at the bottom outside of the tube. I don’t mind solder covering the top of the flange, as I grind this back anyway, so it gives me more to work with in that regard.
2. Feed the solder in from the back (the inside top of the ring). You might need to go around two or three times with the heat and solder.
3. Once you think you are done with the solder, check that you have a nice curved filet of solder at the top/rear of the flange (where it meets the tube) and also the outer side (where it joins with the tube flare.
4. If you don't have proper welding gear, try and get a friend to hold a second torch (I have a Bernzomatic ts8000 which I think is really good). Failing this, stick the whole thing in the kitchen oven for 15 minutes before you start with the single gas torch.

I used 2% silver solder (check the MSDS for nasties) and no flux.

[Cletus_Spuckler]

Sizing and Shaping

I grind back the excess solder and copper using either an angle grinder or a bench grinder. To be honest, I could use some advice regarding this as this is hardest part of the process for me. It is taking about 2 hours to grind back / shape each flange!

I have a ferruled end cap which I use a guide for sizing and shape. I keep the diameter the same as that of the end cap. I grind the outside thickness down to 2.5mm. Once I have my bubble caps and gaskets, I might find that the flanges need to be a bit thinner. I try to create a slight chamfered/angled profile to the top of the flange. I don’t think it matters if the top is flat though.

Keeping with the measured approach, I have scribed a 50mm and 5mm grid onto a large, thick, flat board; and use this as a platform to align my copper work, jig and grinders. I fix the grinders in place and allow for the copper to slide backwards and forwards into the grinding wheel. I have the best accuracy and precision when using the side of the wheel on my bench grinder, but this method takes forever to complete. It’s much quicker with the angle grinder, but I don’t have nearly the same leave of precision (despite trying things like attaching it to a block of wood for stability).

I could do with some advice to speed up this part of the process. I want to keep using the side of the bench grinder’s wheel. My thoughts on this are:

1. My knowledge on grinding tools is limited
2. Bench grinding wheels are not designed to be used on the side, so this could be dangerous
3. Maybe a more course grinding wheel would help?
4. I need to buy a dressing star and dress the wheel properly
5. How do others do it?

Your thoughts?

This still has cleaning up to be done. I'll finish it off with the Dremmel.

[cede]

Really nice work !
Keep on

[Yummyrum]

Really great post Cletus .

I've tried a similar process of grinding an angle onto the flange but I used my bench grinder and rotated the pipe/flange in my hand while resting it on the edge of the grinder platform .....its all a bit dodgy but I got close enough . I agree its time consuming .
I like your flaring Jig and the had the same problems with necking of the pipe with annealing . You must be really patient , my attempts to flare without annealing ended up with split flange .

[Cletus_Spuckler]

Thanks guys.

Yummyrum, I think we are probably using a similar approach with the grinder. Do you dress the side of your wheel? And yeah, Im pretty patient with it the flaring. No splits. Just a tired arm (and pissed off neighbours) after 20 minutes with a somewhat heavy hammer!

Here’s how I set up my bench grinder.

As I said, I am not sure that grinders are designed to be used on their side(using the front of the wheel, I can't get it close enough), so using one like this might be considered dangerous.
I don’t yet have a dressing tool, which explains the highly glazed wheel. This means I couldn't dress the side of the wheel either, so wasn’t getting much abrasion from the side. That’s probably why it took two hours to do one flange! I'm going to order a star type dressing tool.

[still_stirrin]

A lathe would be nice. Setup would take a while, but once you’re cutting chips it would smooth up nicely. You could even finish up with some emory cloth.
ss

[Cletus_Spuckler]

SS; Sure would. I've never used one, but am guessing it can't be as hard as learning how to do everything else that we do with this hobby!

Reducer

I am pretty happy with the way my 2” - 4” keg adapter is turning out. I wanted to keep is as short and strong as possible, with a minimum of soldered on pieces. I was really happy with the result. I still need to grind back the flanges and clean it all up with the Dremel (sorry again neighbours).

Before making it, I considered butt welding a narrow section of 2” and 3” tube to a flat ring. I also considered making my own cone reducer out of some sheet. I decided against both options and went with a modified plumbing store reducer. I reasoned that this would be the strongest option.

Despite only having about 10mm to play with, I was able to flare out the 4” end (over the side of a piece of steel) to make an easy flange (didn’t use a jig this time).

It was not possible to flare the 2” end of the reducer as it was very short. It was however socketed, so I just flared a short section of 2” tube and soldered this (with two flange rings) to the reducer.

[Cletus_Spuckler]

[pfshine]

Looking good. Looking real good. Keep it up. Perhaps I missed it but what kind of bubble plates are you going to make? A single large cap or several small caps?

[Big Stogie]

That’s nice work !!

[Cletus_Spuckler]

I’m overdue to for a build update. Sorry about the delay, you know how it is.
Regarding grinding back the flanges, I think my biggest issue was not dressing the grinding wheel. I bought a crappy $20 dressing star from a discount tool store. After fixing the plastic handle which melted after 5 minutes of use, dressing the wheel has helped my grinding drastically. I am still using the side of the grinding wheel (disclaimer, I do not believe this is considered a safe method of operation).

[Cletus_Spuckler]

Looking good. Looking real good. Keep it up. Perhaps I missed it but what kind of bubble plates are you going to make? A single large cap or several small caps?

Bubble Cap Plates

Just to recap; the aim of my Stage One build is to produce a neutral 95-96% ABV EtOH, with very clean fractional separation. I want production time to be drastically shorter than that currently required with my 2” boka. Stage One will result with one or two 4” bubble plates at the bottom of a 1.5m packed 4” column. I hope to be able to run it at 4400kw (240v).

I believe the purpose of the bubble plate(s) is to quickly bring the ABV up; thereby increasing the columns effectiveness in fractional separation. My simplistic understanding is that, increasing bath depth and increasing slits in the caps, both increases the opportunity for liquid / vapour interaction; thereby increasing vapour ABV.

I am guessing the key questions here are:
1) what bath depth do I go for; and
2) what bubble cap design do I use

I’m thinking I will use 6 x 1/2” risers with 3/4” caps and a 3/4” down comer and that bath depth will be about 9.5mm (3/8”). This depth would be about 2mm below the top of the riser.
In this design, the risers and down comer would be soldered to the plate, with the caps attached by tabs and small stainless steel bolts.

An alternative could be the single large pro-cap type design, which might look like this:

In this design, the down comer would be soldered to the plate. The riser and vapour lock would be soldered together; then held in place by being bolted to the cap.

[Cletus_Spuckler]

My other question is about gaskets and which is the best approach?

The two options I am currently considering are either:
- 2x everlasting gaskets, or;
- 1x store bought PTFE with the bottom ridge filed down (the plate would nestle inside the top ridge).

It would be great if there was a ‘< >’ profile option.

[raketemensch]

What I did was remove material from the inside of the store-bought PTFE gasket until the plates fit right inside them. I did a truly crappy job of this, because I was in a hurry and didn’t have the right tools, but they still work perfectly two years later.

Even if you can get a good seal with one ridge removed, getting everything aligned and clamped is a lot easier with both of them intact.

[Cletus_Spuckler]

I did a truly crappy job of this, because I was in a hurry and didn’t have the right tools

Haha, sounds like my typical approach!

Even if you can get a good seal with one ridge removed, getting everything aligned and clamped is a lot easier with both of them intact.

I'm guessing that you have proper stainless steel sanitary fittings with the centering groove? My easy-flanges don't have those.

[Cletus_Spuckler]

Regarding bubble plates / caps; I'm still pretty unsure about the best design approach, so will have to do more research. I would love it if someone could help me out here with advice or a link to a good post (I have been looking - Harley03 had a lot of good advice)!

My main questions are:
1) Benefits of single large cap or six small ones

2) Is there a way to NOT need to solder anything to the plate?

3) Best cap slot shape (triangles or rectangles) and size (height and width)?

4) Optimum liquid depth for high proof (90+ abv) alcohol?

5) Height difference between top of riser and top of down comer? I've read that the riser can actually be lower than the down comer due to back pressure in the cap. Can anyone verify this?)

6) Do the top of caps need to be domed or coned? Or can they just be flat? Is there a good method to dome a store bought end cap?

7) Optimum specific riser, cap and down comer dimensions (diameter and height) for high proof alcohol?

Im currently thinking:
riser = diameter 0.5" x length (?)
down comer = diameter 0.75" x length 3.0"-4.0"
cap = diameter 0.75" x standard end cap length (0.75"?)
slot shape = triangles 3.5mm - 4.0mm high

Any help on the above questions would be greatly appreciate.

[Cletus_Spuckler]

LM Slant Plate Section

In the meantime I've been finishing my LM slant plate section.

Key Dimensions and Figures:

4" diameter x 120mm tall
40mm height separation between plates
10mm plate overlap
13 degree plate angle
maximum 0% reflux outflow of 500ml /minute
holds maximum 10ml of liquid

I have two modifications on the typical slant plate build. One being, a removable top plate to allow for easy solder clean up and easy ongoing cleaning.

[Cletus_Spuckler]

Now for the build!

I first marked out the slots using a paper template (shown later in this thread) and cut the top slot.

I then hammered out a ring from a piece of 4" tube. I flared out 0.75" of tube and cut, then hammered in 0.75" of tube. This gave me a flat ring of about 1.5" which would form the channel/ holder for the removable top plate.

Finally , I cut the annealed top plate channel / holder to size and soldered it in.

[Cletus_Spuckler]

Next I created a wooden form, to mold a channel / holder for the top plate; and for the plate itself.

I gently hammered the wooden form against the soldered ring, to press out the desired channel / holder shape.

I then used the same wooden form to create the top plate.

Next came the bottom plate. I did something a little different here also...

[Cletus_Spuckler]

Bottom Plate:

I figured a 4" slant plate would be more prone to smearing than that of a 2", due to increased liquid holding capacity on the plates. To reduce liquid holding capacity, I decided to do something a little different and create a narrow channel below the bottom plate.

After cutting the slots using a paper template (I designed this in Sketchup); I cut and shaped the left and right bottom plate, plus the channel.

Left and right bottom plates

Channel

I first soldered the plates; and then the channel separately.

Top view

Top view

Bottom view

[Cletus_Spuckler]

I soldered in the thermo port and outlet tube in last.

Top view with bricks to hold tube in place (the other tube is held in place with a clamp)

Upside down

Right way up

Top view

Bottom view

Finally (or so I thought), came the clean up.

As is so typical of me; after spending an entire day on the Dremmel cleaning up my dodgy solder joints; I overworked the piece and sanded a hole right through the channel!
In hindsight, the 5/8 copper tube I used for the channel was way to thin.

Bottom view showing hole

[Cletus_Spuckler]

I decided to make a sleeve using thicker copper and solder this over the entire outside of the channel.

I soldered this in place, cleaned it up again, and would you believe; in the clean up process I made another hole through the original thin channel!
So, I decided to cut out as much of the original channel as I could, make a third channel and insert that to the inside of the channel.

Finally I cleaned the whole thing up - for the THIRD TIME!
I have to just leave it alone now as the copper walls a getting thin due to all the 1200 grit sanding Ive been doing!

[Cletus_Spuckler]

The end result:

Front view

Side view

Top view with top plate removed

Top view with top plate in place

Bottom view with top plate removed

Only thing left to do is trim the tubes and attach some SS fittings. I will probably try and clean the inside of the tubes while I'm at it.
I'm adequately happy with my work. As usual, I've over worked the piece. In addition, there are quite a few little holes in the solder fillets. These are water tight as they don't go right through; but I suspect that they will collect grime.