Considering building a shotgun

[MooseMan]

Ok, so inspired by Puck Junkies shotgun build thread, I can't stop looking at the length of 2.5" copper I have in the garage that's left over from my column build last year.

It's a bit over 500mm long, will need a flange bashed out at least on one end to connect to my elbow and I have the choice of the following tube sizes for vapour tubes - 28mm/22mm/15mm

I've not even begun to try working out how many of each size I could get into a 2.5" shell (Sorry about the inches and metric at the same time, I'm British!) or which size and number would be the best efficiency wise, I'm hoping that those here who have built and run a large diameter shotgun can share what they know and help me decide before I waste materials.
I do understand that I'm looking for maximum water to vapour tube contact and how I can direct that with vee cuts in the baffles etc.

I don't have any copper plate but could cut some 32mm thick walled tube that I have, lengthways and flatten to make end plates and baffles.

I'm honestly only planning to make this with 2.5" because I have the material, and my Dimroth does limit power to the boiler during strip runs, but if what I'm planning is over kill I'd rather be told before I even start.

[Wildcats]

Ok, so inspired by Puck Junkies shotgun build thread, I can't stop looking at the length of 2.5" copper I have in the garage that's left over from my column build last year.

It's a bit over 500mm long, will need a flange bashed out at least on one end to connect to my elbow and I have the choice of the following tube sizes for vapour tubes - 28mm/22mm/15mm

I've not even begun to try working out how many of each size I could get into a 2.5" shell (Sorry about the inches and metric at the same time, I'm British!) or which size and number would be the best efficiency wise, I'm hoping that those here who have built and run a large diameter shotgun can share what they know and help me decide before I waste materials.
I do understand that I'm looking for maximum water to vapour tube contact and how I can direct that with vee cuts in the baffles etc.

I don't have any copper plate but could cut some 32mm thick walled tube that I have, lengthways and flatten to make end plates and baffles.

I'm honestly only planning to make this with 2.5" because I have the material, and my Dimroth does limit power to the boiler during strip runs, but if what I'm planning is over kill I'd rather be told before I even start.

Sounds like you have a good plan. I too am getting ready to build a shotgun. I'm just going with 2" and 1/2 " x 21"
With 4 vapor tubes. But in your case I would think you could at least fit 5 ??? And maybe go a few inches shorter in the length. Maybe as short at 17 inches... But that's just my guess. Hopefully someone with my experience will chime in. Good luck with your build man. Hope the solder flow they way you want sir!

[Salt Must Flow]

For a 2.5" diameter shotgun, I'd go with 1/2" copper pipe. Just draw it out to scale and see how many pipes will reasonably fit. Inevitably you'll have to create a couple of paper templates so it's not a waste of time to draw it out.

You don't need copper plate specifically. You can split a piece of copper pipe, anneal it with a torch and flatten out out to make plate.

[Berserk]

When I designed my shotgun I used this tool: Engineering Toolbox - Circle in circle calculator

When you use the tool add like 50% to the OD of the inner tubes. That way you ensure a good flow of water between the pipes.

I don't know the exact inner diameter of 2,5" pipes, but you should definitely be able to get 5x 15mm pipes in there, probably 7x if you want to! Add some baffles and you'll have a great shotgun.

It might be overkill, sure, but I see no real downside to it except that it might be a bit heavier than it needs to.

[MooseMan]

I thank you all for your input gents.
Wildcats I hope you will put up a build thread of your own condenser, that would help me along for sure, as I'm far from a practiced solderer. I had never really needed to do any until I started my still build and suddenly I'm at it all the time.
Good luck yourself!

Salt, I've asked my local scrap man to keep back any copper plate that he comes across, but my fall back is a length of old 32mm heavy copper pipe that I have, it's really thick walled. I'll cut, anneal and bash that flat in 100mm strips for plate if I have to.

Berserk, that calculator is absolutely priceless!
You should get the mods to put it in a sticky for us all, it's such a useful tool.

I'd not yet started looking at details for vapour tube sizing and number, but you've saved me hours man!
Thank you for going to the effort of linking it for me.

[shadylane]

My 2 cents worth.
Compared to a simple liebig.
The only reason to build a shotgun product condenser, is if length is a problem.
If length is really critical, a dimroth is simpler, shorter, cheaper and easier to built option.

Bang for the buck is a liebig with a 3/4" or 1" vapor tube and size the length to match the boiler power.
If a 1" tube is too small, a dimroth where the cooling water flows inside the tubing and the alcohol condenses on the outer surface.

1/4" or 3/8" copper tubing is cheap and so is copper foil for the outer shell.

[Saltbush Bill]

I have to agree with Shady.....while shot guns look cool ,in many cases they are over kill.
A good long liebig is more than enough for most Hobby aplications.
Liebigs are cheap , easy and quick to build in comparison to a shot gun.........I'd go that path first.......if you don't like the result then you can always go the more complicated, harder and more expensive route later.

[Demy]

I built a small shotgun and I don't regret it, it works very well even if it is small in size.

[Bushman]

Salt, I've asked my local scrap man to keep back any copper plate that he comes across, but my fall back is a length of old 32mm heavy copper pipe that I have, it's really thick walled. I'll cut, anneal and bash that flat in 100mm strips for plate if I have to

This was going to be my suggestion. I found you really need to stop by on a regular basis and check through yourself.

[Blove88]

I built a 2" copper Liebig with 1" on the inside 30 in long and besides the pipe all I needed was 3 2"-1" reducers 1 2" tri clamp ferrule a drill bit and step bit and witch ever hose barb connectors for your water input and output and it will keep up with a 5500w element at 20 amps or knock down a qt jar every 10 min

[MooseMan]

My 2 cents worth.
Compared to a simple liebig.
The only reason to build a shotgun product condenser, is if length is a problem.
If length is really critical, a dimroth is simpler, shorter, cheaper and easier to built option.

Bang for the buck is a liebig with a 3/4" or 1" vapor tube and size the length to match the boiler power.
If a 1" tube is too small, a dimroth where the cooling water flows inside the tubing and the alcohol condenses on the outer surface.

1/4" or 3/8" copper tubing is cheap and so is copper foil for the outer shell.

I hear you Shady.

I already have a Dimroth in a 2.5" copper shell that works perfectly well for spirit runs, but I'm having to back off the heat when stripping as the shell gets hot and starts to warm the product up to the point where I can see vapour.
I was planning to stick a few heatsinks to it on the next strip runs and see what that does, but since I have materials I thought I'd just build something more efficient.

I could just go 28mm over 22mm Liebig and go long if that's going to cope with my full 4800watts easy enough.
I've got all of the materials to do either option.

[MooseMan]

A question on tube sizing then.

Currently I have a modular CCVM that I flip the parts over and run in pot mode for stripping, exactly as Kimbodius does.
Only difference is, I step up from 2" at the keg, to 2.5" right the way through the rest of the vapour path.

If I was to go 2" from the keg straight down to inch with a long Liebig for stripping, would I be getting less potential output/speed than if I stay at 2.5" right through?

[shadylane]

If I was to go 2" from the keg straight down to inch with a long Liebig for stripping, would I be getting less potential output/speed than if I stay at 2.5" right through?

On a keg sized potstill.
Increasing the riser diameter from 2" to 2.5" isn't going to make a difference in speed.
Nor would using 1" tubing from the keg, to a condenser made with 1"id.

[MooseMan]

If I was to go 2" from the keg straight down to inch with a long Liebig for stripping, would I be getting less potential output/speed than if I stay at 2.5" right through?

On a keg sized potstill.
Increasing the riser diameter from 2" to 2.5" isn't going to make a difference in speed.
Nor would using 1" tubing from the keg, to a condenser made with 1"id.

Thanks shady, that is exactly the answer I was looking for, clear and concise.

Ok with that clear I can look at a completely separate head for the keg, just for stripping.
2" from the keg, down to 1" and a bit of creative jointing to make a 28mm over 22mm Liebig. A good long one!

[Salt Must Flow]

If I was to go 2" from the keg straight down to inch with a long Liebig for stripping, would I be getting less potential output/speed than if I stay at 2.5" right through?

Pipe size does not determine output rate with a pot still. Output is determined by power/energy input. Think of it like steam. More heat = more steam. If the pipe size is small, the rising vapor must travel faster than if the pipe were larger because larger pipe has more volume. Vapor speed in a pot still won't affect the output rate.

[MooseMan]

If I was to go 2" from the keg straight down to inch with a long Liebig for stripping, would I be getting less potential output/speed than if I stay at 2.5" right through?

Pipe size does not determine output rate with a pot still. Output is determined by power/energy input. Think of it like steam. More heat = more steam. If the pipe size is small, the rising vapor must travel faster than if the pipe were larger because larger pipe has more volume. Vapor speed in a pot still won't affect the output rate.

Thanks for that, I often need that kind of explanation for something to "Sink in" no matter how straight forward it might seem.

I'm pretty sure I can get an unused 2" to 1" tri clamp reducer from work, so being a major tight ass, that's going to drive the direction I go in!

[MooseMan]

I have to agree with Shady.....while shot guns look cool ,in many cases they are over kill.
A good long liebig is more than enough for most Hobby aplications.
Liebigs are cheap , easy and quick to build in comparison to a shot gun.........I'd go that path first.......if you don't like the result then you can always go the more complicated,
harder and more expensive route later.

Ok, so despite the title of this thread and my initial intention based on what materials I have available, I'm gonna go with what you and Shady are saying Bill, and see how it performs.
I've dug out everything I need to put a Liebig together this morning except for the reducers, so I'm off to the plumbers merchant shortly!

I'll make a new post and put some pics up when I start putting it together, in the hope it might help anyone else who is not sure which way to go on a condenser.

[Wildcats]

I have to agree with Shady.....while shot guns look cool ,in many cases they are over kill.
A good long liebig is more than enough for most Hobby aplications.
Liebigs are cheap , easy and quick to build in comparison to a shot gun.........I'd go that path first.......if you don't like the result then you can always go the more complicated,
harder and more expensive route later.

Ok, so despite the title of this thread and my initial intention based on what materials I have available, I'm gonna go with what you and Shady are saying Bill, and see how it performs.
I've dug out everything I need to put a Liebig together this morning except for the reducers, so I'm off to the plumbers merchant shortly!

I'll make a new post and put some pics up when I start putting it together, in the hope it might help anyone else who is not sure which way to go on a condenser.

Yeah it took me like 15 minutes to build my Liebig. You will be glad you did. I have to run my water very slowly thru it or it'll start huffing. Have fun and stay safe

[Salt Must Flow]

MooseMan, regardless whether you intend to make a shotgun or a Liebig condenser, there are different ways of plumbing water inlets and outlets. I like to buy brass end caps or plugs, drill a hole through it, grind to contour it so it mates with the round pipe and solder it directly to the water jacket. You could also buy a brass nipple, cut it in half, grind it and solder it to the water jacket. It just depends on whether you want male or female threads.

You don't need more expensive reducer tees or even copper fittings which are significantly longer (protrude out longer) than the fittings I've described.

[MooseMan]

MooseMan, regardless whether you intend to make a shotgun or a Liebig condenser, there are different ways of plumbing water inlets and outlets. I like to buy brass end caps or plugs, drill a hole through it, grind to contour it so it mates with the round pipe and solder it directly to the water jacket. You could also buy a brass nipple, cut it in half, grind it and solder it to the water jacket. It just depends on whether you want male or female threads.

You don't need more expensive reducer tees or even copper fittings which are significantly longer (protrude out longer) than the fittings I've described.

Your advice to grind a brass nipple to the contour of the jacket would have been perfect and definitely fits my frugal ways! Haha

However I was lucky enough to score a bag of free fittings when I was putting the main still together, so I had just what I needed already for water connections.
I wanted to build it with reducer tees as I can get them pretty cheap locally from a good plumbers merchant and they give a nice neat finish.

Wildcats it took me a fair bit longer than 15mins to build my Liebig today, all the tube was pre used so a bit of cleaning up needed before I even started!

[shadylane]

MooseMan, regardless whether you intend to make a shotgun or a Liebig condenser, there are different ways of plumbing water inlets and outlets. I like to buy brass end caps or plugs, drill a hole through it, grind to contour it so it mates with the round pipe and solder it directly to the water jacket.

Something like this.
viewtopic.php?t=49639

[ecir54]

used copper fitting cut down on mine soldered with stay silv 5

[Sporacle]

Moose, the water fittings can be as simple as a piece of half inch soldered into the side with a piece of garden hose slipped over the top, add a hose clamp and your away.
Make sure you factor in temp and kinking and all that stuff

[MooseMan]

Moose, the water fittings can be as simple as a piece of half inch soldered into the side with a piece of garden hose slipped over the top, add a hose clamp and your away.
Make sure you factor in temp and kinking and all that stuff

Yes I'll be going exactly that route soon to make a simple little Liebig for a stovetop setup that a friend has requested.
Either a couple of stubs of copper, or as Salt suggested, brass nipple ground to a good fit.

[CoogeeBoy]

......if you don't like the result then you can always go the more complicated, harder and more expensive route later.

Now you tell me!

Just finished my Shotgun, will post photos when I clean it up

[MooseMan]

......if you don't like the result then you can always go the more complicated, harder and more expensive route later.

Now you tell me!

Just finished my Shotgun, will post photos when I clean it up

Hahaha!

Looking forward to the pics CoogeeBoy!