Ok, I have made a new picture, I hope this makes it more clear.....
The stuff to be distilled sits in the steel coffee/paint can, which is sitting in a pot of hot water on the stove -(For my foafs stove this was about 6-7, the water doesn't need to be boiling, just hot)
This causes the stuff to boil and turn into a vapor, which will then try and escape via the copper pipe set into the tight fitting lid of the paint can(use teflon tape to seal leaks)
You can use a product called J B Weld to bond any metals.
The vapors travel through the 90 degree angle pipe fitting, all these copper pieces can be found at your home improvement store.
The pipe leading to the left is bent by hand so that vapors which condense will run down to the tip and drip out. The condensor is made around the copper pipe by bonding two bell reducers to the pipe with a piece of PVC pipe in between, about a foot and a half long is PLENTY long, a foot is just sufficient
This piece of PVC pipe has holes drilled in it, with clear plastic hose sticking out of the holes, and sealed with silicone sealant
These hoses run down to a fish tank pump sitting in ice water, whether this be in a bucket, your sink, or a big bowl,
but ice is required to ensure proper condensation, and you will have to add more, if you're distilling a lot.
The vapors travel through the condensor and are exposed to the ice-water-cold walls of the copper pipe, due to the water from the reservoir flowing through the PVC via the hoses, and they are thus condensed into a liquid, which drips into the reservoir bowl.......
In the case of absinthe, the alcohol, water, herbal oils and assorted compounds boil off together in a mixture called an azeotrope- this means the molecules sort of get caught up with each other as they are boiling out, while other, heavier molecules get left in the liquid phase, resulting in only certain things coming out of the pot.
This leaves ALL the bitterness out of your absinthe, resulting in a much smoother, nicer stuff
I think that about covers it......... Any more questions?
Oh yeah, the pipe he uses was 1" copper, and 2" PVC.
Using a smaller pipe resulted in too small asurface area for the vapors to condense on, and lots of absinthe steam escaping into his kitchen- MMmmm Aromatic
Go for the 1" for sure
Also, I think that you need fractionation(the purification caused by vapor condensing and then re-evaporating from a column packing providing lots of surface area)
if you're going to be distilling from nasty mixes like mash