Page 1 of 21

Thumper?

Posted: Thu Feb 14, 2008 5:53 pm
by WarEagle57
So i am trying to decide if I want to use a thumper or not on my pot. My question that i have is about what to fill the thumper with. It will most likely be a mason jar. The website says "the jar is half filled with liquid (water or mash or tails) so that the vapour from the still will bubble up through it; then the vapour coming off it is collected & cooled as per normal. It acts as a second distilling chamber using just the heat from the vapour, and lifts the purity from 50-60% to 70-80%, hence improving what might otherwise be a very mediocre design. Don't make the thumper too small, and start it off with liquid already high in alcohol." So should i fill it with water or mash?

Thanks guys!

Posted: Thu Feb 14, 2008 6:39 pm
by As-Ol-Joe
A thumper is not really needed unless you are going to run your still hard and fast and have a boil over. The thumper does work as a second distillation, but why not do several stripping runs then do a spirit run?

I think most people will tell to just fill the thumper with water.

Welcome aboard.

Posted: Thu Feb 14, 2008 6:41 pm
by Dnderhead
thumper should be about 1/4 size of boiler and charged with mash or better low wines it is just like a secant still if you dont have alcohol
in it you cant git out ( if you jest use water, alcohol will stay in water
until it gets built up to high Prof)

Posted: Thu Feb 14, 2008 8:25 pm
by violentblue
Do you think a thumper full of molasses wash be a good way to gain a little extra body in a rum?

Thumper?

Posted: Fri Feb 15, 2008 2:17 am
by stillsmokin
I like that idea, maybe do a run of lighter rum and use a dark rum in the thumper to add flavor. It would be interesting to do one run with, one without to see the difference.

Posted: Fri Feb 15, 2008 5:07 am
by goose eye
some folks will put a fire under the doublein keg to get it close to temp then rake the coals back when the ketle kicks in. cant tell you what to
put in it but i can tell you never put backins in it. the taste will come thru
an it mite not much mater on bourbons an reyes it will ruin brandy if
it gonna get gone clear.

so im tole

Posted: Fri Feb 15, 2008 7:21 am
by Dnderhead
ifin you going to put flavor in it then you have "gin head" not thump er

Posted: Fri Feb 15, 2008 11:05 am
by pintoshine
I run a thumper on all my pots. It helps to make the cuts and helps the abv stay up higher longer. If you look for other posts about thumpers you will find some graphs of doubling runs I have done witht he thumper such as this one.
I find the thumper to mellow out the spirits much better than without one. Most believe it gives two distillations in a single run but it is not quite that efficient. It is more like 1.5 distillations.
Water makes for very clean spirits. Three runs through my pot with a thumper will make a very clean vodka at about 92% abv.
If you run wash in your thumper, you'll push tails into the condenser early. If you run heads and tails from a previous run, you get really high abv to start but also more heads and tails.

I like mine. It serves me well.

Posted: Sun Feb 17, 2008 8:32 am
by TN.Frank
I'm running a 2qt mason jar made into a thumper and I really like it over not running one. I can do a single run now and get around 160-170 proof instead of having to do two runs for the same thing, that saves on electricity and water. I just put about 1/4 of the way with water and as soon as it saturates with alcohol and reaches temp it'll act like a second cooker and the alcohol comes off twice as strong as it went in. Another plus is that even though I don't run that hard if something does happen that the cooker pukes over it'll be caught in the thumper and not get into the finished product.

Posted: Mon Feb 18, 2008 1:18 am
by Harry
violentblue wrote:Do you think a thumper full of molasses wash be a good way to gain a little extra body in a rum?

Try this...

Posted: Mon Feb 18, 2008 8:19 am
by violentblue
building my still right now, what do we think of the mason jar thumper? I was planning to make everything out of copper, but have been thinking that glass might be nice for visual monitoring.

I've seen the diagram above before, considering the size of my pot, I'm not sure two thumpers would work (not enough steam to drive them both).

however if I ever decide to go into production, thats definatly the model to use.

Take a look for Pussers rum on google, they use wooden stills and wooden thumpers, if your still were big enough you could use an oak barrel as a thumper keg, should make for some interesting flavors anyway.

Posted: Wed Feb 20, 2008 10:03 am
by violentblue
violentblue wrote: I've seen the diagram above before, considering the size of my pot, I'm not sure two thumpers would work (not enough steam to drive them both).
I'd like to revise this comment, after running my mason jar thumper, I think that one could easily run two like pictured above.

Its my understanding that the perfect sized thumper is 1/2 the size of your boiler, if you were running two thumpers, would you stagger them, as in one at 1/2 size then the second at 1/4 size, or do both the same size?


My next question is regarding temperature cut off points, typically these are taken at the top of the colum, or head, but in a thumper setup, would you take them at the output of the thumper just before the worm?

Posted: Thu Feb 21, 2008 2:40 am
by goose eye
same size

these boys aint much woryed bout how hot it is. they rekon by what comein out .
if that themometer breaks is you gonna be lost.
see it come with your eyes an smell an leave with your eyes taste an smell.

so im tole

Posted: Sun Feb 24, 2008 2:07 am
by shadylane
I run a thumper that is the same size as the boiler.
These are my opinions.

For whiskey, fresh mash works best in the thumper.
you can flavor neutral spirts this way

For efficiency heads and tails are used.
But are best added back to the boiler.

For clean shine, I use water.
Save the thumper juice to top off the boiler.


There is no substitute for careful cuts. But you can dump it back in the still.

Since every batch of mash is different, you can't use a thermometer for your cuts, use your nose and taist buds, cut your sample distillate with water before testing. If you see any fusel oil you went to damn for into the cut.

Practice and learn.
Then tell me what works, I'm tired of learning from my own mistakes.

Posted: Sun Feb 24, 2008 6:08 am
by Ricky
what do you guys think of using a thumper on a double boiler rig? will there be enough heat? mine without a thumper seems to want to shut down at the end of a run.

Re: Thumper?

Posted: Mon Aug 18, 2008 5:27 am
by EssenceExtractor
I too plan on using a 2L Mason jar. I can't seem to come up with an easy idea for a lid. What are the lids made outta anyway (they rust if scratched). Wonder where I could find some copper to make a new disc to be screwed down, then solder the copper pipes in. This site is amazing, keep on runnin'.

Re: Thumper?

Posted: Mon Aug 18, 2008 5:39 am
by pintoshine
I modified a 4" brass cleanout. I drilled and tapped it and the jar slid right up into it. The gasket is cork.

Re: Thumper?

Posted: Mon Aug 18, 2008 5:44 am
by theholymackerel
A thumper is just a secondary boiler powered by the primary boiler.

I know folks use glass thumpers, but I doubt it's smart. I mean think about it... a glass boiler? It's not even rolled borosilicate glass. Mason jars are cheap glass made in a mold.

Do whatever yall think best, this is just my two-cents worth.




I wish ya luck (especially those usin' glass boilers).

Re: Thumper?

Posted: Mon Aug 18, 2008 6:32 am
by Dnderhead
I agree I would not use glass , I had an oz fall of a shelf and flair up and that was bad, Id hate to see what a cuple gallons would do

Re: Thumper?

Posted: Mon Aug 18, 2008 9:41 am
by EssenceExtractor
What is another common thumper/boiler then?

I'm a poor student too...

Actually I could just use another pot 1/2 the size of my boiler, clamp and dough-up lid after soldering copper pipes into the lid. Man thats a lot of work.

Re: Thumper?

Posted: Mon Aug 18, 2008 9:46 am
by goose eye
aint they got ss screw on lid canisters.
ole boys always wanted to see inside one when it changes

so im tole

Re: Thumper?

Posted: Mon Aug 18, 2008 4:33 pm
by violentblue
I used a mason jar, with a lid cut from copper an sealed with the mason jar ring and paste.
can't say it worked well though, size was too small for my 6 litre pot, I was a little nervous about running glass like that, only rtan it a couple times.
next unit I build I'll make a matching pot and thumper from copper using Pints plans using a glass level guage.

not exaclly low cost but, anything worth doing .... and all that.

Re: Thumper?

Posted: Tue Jan 13, 2009 10:55 am
by minime
Don't know if you guys are familiar with the design of the Charles 803 fuel still. The plan shows the bottom of the three inch column being utilized as a doubler or thumper. It is designed as a stripping column and the spent wash serves as the charge down there. From what you guys are saying, the volume in the bottom of the column is not big enough to accomplish anything much? Is that a fair assessment? I've not seen this discussed on the fuel forums an it is quite a popular design even today.
Nanda Warren daughter of the original designer continues to sell blueprints for the still and is attempting to get a forum going devoted specifically to the design.
http://forum-alcohol4fuel.com/viewforum.php?f=2" onclick="window.open(this.href);return false;" rel="nofollow
I bought blue prints about 3 years ago but have never attempted to build it. I was suspicious of the doubler section from the beginning and didn't think it would be effective.
Any opinions, comments, experience with the design?
http://www.alcohol4fuel.com/" onclick="window.open(this.href);return false;" rel="nofollow

Re: Thumper?

Posted: Tue Jan 13, 2009 11:16 am
by pintoshine
What size would you say the doubler section is? It is more a function of depth rather than volume.
The depth is affected by either an overflow, or the amount of vapor coming in vs. the amount going out.
The amounts are more controlled by the container heat radiation. If the material the container is made of is insulating such as a keg, the volume needs to be large. If the container radiates a lot of heat it needs to be smaller. Metal thumpers which radiate a lot of heat without insulation, fill very fast and maintain a high level of liquid because less heat is used to reboil the vapor going out. So the reboiler/double section of the c803 might be just about right from the diagrams I have seen.

Re: Thumper?

Posted: Tue Jan 13, 2009 7:04 pm
by minime
pintoshine wrote:What size would you say the doubler section is? It is more a function of depth rather than volume..
The doubler section is only 8 inches tall. Feed line is 1 inch tube turned to point down in the column and there is a baffle plate standing a couple of inches off the bottom. (a plate with holes drilled in it) the siphon to bleed the spent wash exits under the baffle and rises to the same hight (8 inches) The entire thing just doesn't seem to be large enough to be very effective and the throughput is claimed at 3 gallons per hour of fuel grade alcohol. (90%) from grain mash.(likely at 5% or slightly above that) The whole thing seemed to me to be excessively claimed but I've not seen many complaints regarding the claims. From my experience I don't see how it could work.
If it could work as claimed it's the most efficient stripper out there I'd think. I'm not trying to discredit but just trying to understand fundamentals.

Re: Thumper?

Posted: Tue Jan 13, 2009 7:42 pm
by Hawke
I thought the 803 was more of a rectifier column, with the feed coming from a stripping boiler.

Re: Thumper?

Posted: Wed Jan 14, 2009 4:31 am
by minime
Hawke wrote:I thought the 803 was more of a rectifier column, with the feed coming from a stripping boiler.
Exactly, using the bottom 8 inches of column as a thumper.........

Re: Thumper?

Posted: Wed Jan 14, 2009 6:26 am
by Hawke
Thanks Minime, think I mis-read your earlier post. Yes, it would not be able to achieve the flow rates stated if charged with wash. It needs the low wines to be of any use.

Re: Thumper?

Posted: Thu Jan 15, 2009 12:21 am
by Hack
If that's the design there in the link that minime posted, it doesn't look so much like a thumper as a kind of catch for reflux leftovers. I think it might be useful to find a way to route the overflow tube back to the boiler.

Re: Thumper?

Posted: Thu Jan 15, 2009 5:28 am
by trthskr4
Hack wrote:If that's the design there in the link that minime posted, it doesn't look so much like a thumper as a kind of catch for reflux leftovers. I think it might be useful to find a way to route the overflow tube back to the boiler.
My issue is that the still is so damn tall and needs a large boiler to keep going for any amount of time you need a 10-12 foot ceiling to be able to mount it high enough to return the low wines from the overflow back to the boiler.

My still is roughly 6 feet tall and boiler is 4-1/2 feet tall.