Thumper candidate

[MooseMan]

Ok gents, I've been hovering over this idea of a thumper for a long time.

I know I could use one for stripping the alcohol out of grain and pressed custard, and also for adding fruit to, when distilling my upcoming brandy runs.
But most of all, I want one to experiment with esterification in rum.

I have at my disposal, yet another tea urn (Commercial water boiler, a big one 30L I think) and it's virtually new and fully working. It has a great lid for sealing, handles fixed on with sealed SS bolts inside and a tap that has all SS internals. Even the knob on the top is on a welded SS thread, so I don't have to mess with any of the original build, just the lid connections.

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It seems like the perfect candidate for a thumper/infusion pot/esterification chamber.

Since there's loads of real estate on the lid, I'd like to do separate in and out ports as I may want to block one and use the vessel as a boiler now and again for smaller runs.

My main boiler has a 2.5" tri clamp connection for the riser, but I have the spare Tri clamp bits to step down to 2", 1.5" and 1" if needed.
(I go from 2.5" to 1" for my current Liebig anyway)

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I have copper for the down pipe, 28mm.

So, before I do anything with this, probably on the weekend, any words of wisdom or suggestions are welcome.

My loose plan, is to solder a 1.5" flange on, and use a drilled out blank to fit the down pipe in 28mm, so these sized bits:-

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Then 1.5" out on other side of lid, to a 90 then my condenser.

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I also have a pair of these, that I could use if I can make them work:-

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Tri clamp to threaded female, 16mm internal diameter.

So, what do you guys think?

[Rusty Ole Bucket]

I'm looking forward to seeing what you come up with Moose. Are you planning on using the heating element in the thumper to preheat the charge once you have it complete? I could see where that would be a big time saver and I think it could almost eliminate or at least lessen any water transfer from the kettle to the thumper since the charge will be preheated and condensation should be less.


Rusty

[MooseMan]

I'm looking forward to seeing what you come up with Moose. Are you planning on using the heating element in the thumper to preheat the charge once you have it complete? I could see where that would be a big time saver and I think it could almost eliminate or at least lessen any water transfer from the kettle to the thumper since the charge will be preheated and condensation should be less.


Rusty

Yes that's part of the plan Rusty, I'm hoping that since there is no internal element, for some product I can heat the thumper contents slowly while the main boiler is coming to temp, with the thumper lid off and stirring it.

[Yummyrum]

That might work a treat Moose . I’m imagining that it’s a pretty thin boiler . Probably makes quite a racket while it’s coming to temp . So your slow heat and stir might be quite helpful . Then wrap some heavy blankets around it and let it rip .

I was playing with my thumpers again on the weekend and thick blankets really take the sharp edge of the noise .

[MooseMan]

I plan to fix insulation around the side walls of it Yummy, then a separate slab of insulation taped on the lid, stopping just shy of the edge and cut around the inlet/outlet connections so it won't get in the way.
Then if needed, I could make another sort of "Cowl"of insulation that could be dropped down onto the lid and over the edges. Like a boiler bobble hat!

If it's loud, I've got some thick closed cell foam that I could put on it to deaden the noise a bit. Can't be alerting the neighbours!
Do they really get that loud then?

[Swedish Pride]

I plan to fix insulation around the side walls of it Yummy, then a separate slab of insulation taped on the lid, stopping just shy of the edge and cut around the inlet/outlet connections so it won't get in the way.
Then if needed, I could make another sort of "Cowl"of insulation that could be dropped down onto the lid and over the edges. Like a boiler bobble hat!

If it's loud, I've got some thick closed cell foam that I could put on it to deaden the noise a bit. Can't be alerting the neighbours!
Do they really get that loud then?

Yes.

I made a thumper to be able to run on the grains, was too loud for me.


I've read that smaller holes makes less noise, never got that far

[SW_Shiner]

Im either doing something right, or something wrong. I have a 30L T500 boiler as a thumper for my 50L keg boiler, put together so i could strip AGs on grain. Loaded all the clear into boiler and everything else into thumper. I was looking forward to hearing the thump, but was quite disappointed with the barely noticeable low rumble that came instead.

Edit to clarify, runs were with 3000w input.

[Yummyrum]

Swedish has a perfect recording of a thumper as it comes up to temp . Once the contents are boiling it just sounds like a boiler ….. a gentle rumbling sound .

Wrapping heavy woollen blankets around it while warming up really takes the metallic clink clunk out if it and its more a dull plonk plonk . I was experimenting with mine last weekend . One blanket Mmmm . Two blankets , significant . I recon three and it would be silent outside .

[MooseMan]

I plan to fix insulation around the side walls of it Yummy, then a separate slab of insulation taped on the lid, stopping just shy of the edge and cut around the inlet/outlet connections so it won't get in the way.
Then if needed, I could make another sort of "Cowl"of insulation that could be dropped down onto the lid and over the edges. Like a boiler bobble hat!

If it's loud, I've got some thick closed cell foam that I could put on it to deaden the noise a bit. Can't be alerting the neighbours!
Do they really get that loud then?

Yes.

I made a thumper to be able to run on the grains, was too loud for me.


I've read that smaller holes makes less noise, never got that far

Holy shit SP!
No way could I have that noise coming from the garage!
I do think you could dumb that noise down a lot as yummy says, with some insulation materials.
Slab of foam underneath it, wrap in whatever you've got, more foam on top etc.
I know closed cell foam really takes noise away well.

This leads to a question actually...
I haven't given much thought to the end of the thumper spear yet, but I was planning on making something to spread the vapor out a little, rather than just an open pipe.

So, would many smaller outlets, spaced apart, make less noise than just one?
In my head, there would be lots of smaller vapour bubbles popping, instead of just one big one, so more of a chatter, than a thump?
Or is that not how it works in there?

Edit: Just seen the comment below the video, didn't spot that.

[shadylane]

The video brought back memories of when I was a kid working at a sawmill. Down here in the southern states there was usually a moonshine still at every saw mill. The thumper was nothing more than steel barrel with a slash cut on the end of the injector pipe. Until the thumper came up to heat, you could hear the racket above the sound of the mill running.

I also wonder how much effect the injector design has on the banging noise?

[Rusty Ole Bucket]

I wonder how much effect the injector design has on the banging noise?

I can tell you about my experience from the first 5 runs on the Goat V2 with two different injector designs, two different vessel sizes and with and with out Reflectix.

The 15.5 gallon kettle has a 1" steam wand with the end capped. It has (4) 3/4" holes drilled above the cap with copper mesh inside the pipe before I soldered on the cap to act as sort of a diffuser without getting plugged (I hope). I had another design in place then my downcomer seized into the thumper head so I had to improvise. I'm going to eventually update to the original tee design. The 7.5 gallon thumper keg has a (3/4" to) 1" downcomer with just a slash cut at the end, so basically wide open. I run 12 to 13 gallons at a time in the kettle and 3.5 to 4 gallons in the thumper.

If the 15.5 charge is cold, it makes a muffled gong sort of sound for a little while then settles right out, if the charge is warm, you just hear the boiler sound once she starts to simmer. With 3 layers of Reflectix, side and top, even from cold it's what I would consider quiet. The 7.5 pony keg is the exact opposite. It sounds just like the one SP posted, the insulation helps a little but you can still hear it loud and clear. The last two times I've warmed the charge first and it's helped some, but it hasn't completely eliminated the sound. Thumper's gonna thump I guess.

Rusty

[MooseMan]

Thanks Rusty.
So are you saying that your 7.5 is louder cos it has just one open end on the spear, whereas the 15.5 has a more diffused vapour outlet on the end?

[Rusty Ole Bucket]

Thanks Rusty.
So are you saying that your 7.5 is louder cos it has just one open end on the spear, whereas the 15.5 has a more diffused vapour outlet on the end?

Yeah, Moose, I don't know if that's the cause for sure, but that's the situation. I'm sure the volume of liquid plays some part in the harmonics of the vessel as well, like the 15.5 to 7.5 would have some bearing I would think. I'm just spitballing though, I have no science to back it up, just my observations.

Since you're all enclosed and electric, you could always build a plywood thump box with sound proofing to hold the finished thumper. Something with sound insulation and an air gap would make it workable in most areas I think. I also think the heavy blankets will work well, anything to "deaden" the sound vibrations.

Rusty

[MooseMan]

A thump box I had not thought about at all!

I do have quite a bit of "Stuff" I can try out for sound deadening and insulation, but if it's not good enough, I guess I could put my thumper in a deprivation chamber yeah!

Getting ahead of myself here, I've not even started the thing...
And she's already talking about fitting new bathroom furniture on the weekend

[Yummyrum]

And she's already talking about fitting new bathroom furniture on the weekend

Sux to be you Moose

[Rusty Ole Bucket]

A thump box I had not thought about at all!

I do have quite a bit of "Stuff" I can try out for sound deadening and insulation, but if it's not good enough, I guess I could put my thumper in a deprivation chamber yeah!

Getting ahead of myself here, I've not even started the thing...
And she's already talking about fitting new bathroom furniture on the weekend

, thumper deprivation chamber.

A pack of this and some scrap plywood ....hmmmm.

Be careful Moose, I'm going to drag you into one of my harebrained ideas if you're not careful.

Rusty

[MooseMan]

Drag away, I'm pretty hairbrained myself! Haha

[shadylane]

I'd use a single 2" tri-clamp bulk head fitting on the lid and 6-8 snap clamps to hold the lid down.
Make a concentric injector/take off for use as a thumper. Remove the plastic drain valve and use the same size in SS.

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[Swedish Pride]

A thump box I had not thought about at all!

I do have quite a bit of "Stuff" I can try out for sound deadening and insulation, but if it's not good enough, I guess I could put my thumper in a deprivation chamber yeah!

Getting ahead of myself here, I've not even started the thing...
And she's already talking about fitting new bathroom furniture on the weekend

Go big with your thumper silencer, I wrapped some old hoodies and towels around my thumper when I was experimenting, the only noticeable difference it brought was spilled grain slop on said hoodies

[MooseMan]

Got the new sink and vanity unit fitted in the downstairs toilet and Mrs Moose is happy and cooking Sunday lunch, so that's out of the way!

I'm sticking with my plan to add 2 ports for the lid, so I can cap one and use the vessel as a small boiler when needed.

First one to tackle then is soldering the 1.5" Tri clamp weld ferrule to the lid.
These things don't have much surface area to get a good joint, so I've shamelessly stolen Yummys trick of making a ring from copper wire as a joint fillet.
I got lucky and was at hand when an industrial spark was cutting big cable tails, so I have lots of short bits of really thick copper wire.
I made a ring, but I've decided not to braze the ends together as yummy did, I think the wire is stiff enough to hold shape, soon see!
This is how it looks so far.

IMG_20250613_180146_459.jpg

I've got to file the ferrule to shape a little, so it matches the curve of the lid, then I'll prep and have a go at soldering.
Since I got that SS liquid soldering flux off AliExpress, I'm no longer stressed about soldering stainless at all.

[MooseMan]

Im either doing something right, or something wrong. I have a 30L T500 boiler as a thumper for my 50L keg boiler, put together so i could strip AGs on grain. Loaded all the clear into boiler and everything else into thumper. I was looking forward to hearing the thump, but was quite disappointed with the barely noticeable low rumble that came instead.

Edit to clarify, runs were with 3000w input.

Hey SW, I'd meant to ask you about your thumper spear, since what you have is very similar to me (A T500 is basically just a concealer element wort boiler no?) and you're saying that it runs pretty quiet?

What arrangement have you used for vapor in at the bottom, if you don't mind sharing?

[MooseMan]

Soldered down tube direct to lid by flanging at the top.

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No risk to the existing solder as I heated the copper and let that heat the joint, ring of solder under the flange and just watch for it to settle flat.

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[Swedish Pride]

Nice work moose.
Are you doing something at the end of the thumper as a defuser or are you going open bore?

[Rusty Ole Bucket]

Looking good so far Moose!

Rusty

[MooseMan]

Thanks gents.

Yes SP I'm currently looking at a 90 on the end, then a short straight and end cap.
These will all be soldered together and the 90 to be a push fit onto the downcomer, then if it's not performing how I want, I can do something else!

Plan is, to drill some lines of small holes along the push fitted section, unless someone tells me that's not the best idea?

[SW_Shiner]

Im either doing something right, or something wrong. I have a 30L T500 boiler as a thumper for my 50L keg boiler, put together so i could strip AGs on grain. Loaded all the clear into boiler and everything else into thumper. I was looking forward to hearing the thump, but was quite disappointed with the barely noticeable low rumble that came instead.

Edit to clarify, runs were with 3000w input.

Hey SW, I'd meant to ask you about your thumper spear, since what you have is very similar to me (A T500 is basically just a concealer element wort boiler no?) and you're saying that it runs pretty quiet?

What arrangement have you used for vapor in at the bottom, if you don't mind sharing?

I havent got a pic of the tube on hand, but i just cut a disc of copper that will fit in a plate gasket and soldered a 1/2" tube to it. At the moment its just open on the end till i can get a 90 and some stainless mesh tube for the end.

Thump attach.jpg

The disk it sandwiched between the tee and the reducer and the tube sits about 1" off the bottom. Vapor goes in the top, down the tube, and back up and out the side of the tee to condenser.

[SW_Shiner]

I just put down a brew yesterday (sunday) so ill pay more attention during heat up next time. Maybe i just missed the thumping, but during the runn it was no louder than running without a thump.

[MooseMan]

I can't quite picture what you're trying to explain SW, is this on the end of your thumper spear?

I've just done this, which will be a push fit on the end of the spear, I'll see how noisy it is, and how effective I guess, but if it's no good, I can just whip it off and try something else.

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[Rusty Ole Bucket]

I can't quite picture what you're trying to explain SW, is this on the end of your thumper spear?

I've just done this, which will be a push fit on the end of the spear, I'll see how noisy it is, and how effective I guess, but if it's no good, I can just whip it off and try something else.

Before the spear seized in the head during construction, that was almost exactly the design I was going for except a double set up on a tee for my kettle. I'll be curious about what you think once you try it out, I eventually want to rebuild my head and spear to my original design.


Rusty

[MooseMan]

I can't quite picture what you're trying to explain SW, is this on the end of your thumper spear?

I've just done this, which will be a push fit on the end of the spear, I'll see how noisy it is, and how effective I guess, but if it's no good, I can just whip it off and try something else.

Before the spear seized in the head during construction, that was almost exactly the design I was going for except a double set up on a tee for my kettle. I'll be curious about what you think once you try it out, I eventually want to rebuild my head and spear to my original design.


Rusty

Well that's uncanny!
I wanted to do a tee with holes along one side of one arm, and the opposite side of the other arm, hoping it would maybe start a bit of a circular motion in the thumper and keep it all moving.
But I forgot to buy a tee, then when I had time to get started I just went with what was in my copper fittings stash!

But I can always change out what I've done if it's crap I guess, that's why I wanted push fit at the spear termination.