The biggest issue I've run across with a thumper is simply that you are going to pick up the characteristics of whatever you put into it.
That is to say, if you load it with heads or tails, then the product that comes out is going to tend to be loaded with heads or tails. All those hard-won hearts will be effectively contaminated with inferior product.
But then again, I've heard of fun things you can do with them too--for instance, 'infusing' a run with a differently flavored spirit. I.e., if you load the thumper with a peach liquor, then the resulting product will absorba lot of those characteristics.
In the end, I'd personally recommend building the column that you need to serve your purposes. A basic reflux column can be as simple as a tall copper pipe with some filler material (copper
scrubbies, marbles, you get the idea) that will actually do the job your hoping to accomplish.
I'm happy with my (albeit infrequently used) still with a simple 3/4" copper column that rises for 24". I do a simple stripping run, then one spirit run. I get in the neighborhood of 75-82% on the hearts :).
Hope that helps,
P.S In all of my reading there was no distinction as to thumper size. The smaller the thumper, the faster it would become super saturated, but it would produce Ethanol with more of a bite.
For a long time I've made double runs from the pot still. I'd like to build a thumper rig to cut down on time from running everything twice.
I'm running a 15 gallon keg boiler. I've heard a lot about thumper sizing, how full to fill it and what to fill it with (mash, tail, etc)
I'm not sure what I've read is good advice, and what is just BS.
Any suggestions on starting up a thumper for a 15 gallon keg as far as size, fill volume, and what I'm filling it with?
Thanks and shine safe!