Ok update on the shingle back column.
so I went to the shed yesterday and sat looking at the ugly thing, less than a week old and already looking like it has had a long hard life. I realised some more mods and back to back testing were in order so i decided to give it some more grief.
First up I cut off the external plate drain tubes, crimped the ends of the tubes and soldered them .
I scavenged up any 2" tube and fittings i had, 2 pieces of tube total 300mm and some end caps. I used the caps some 3/4", 1", 3/8" and 1/4" tube and made two plates with bubble caps, installed these into the 2" tube so all I had to do was remove the top from the column and install the tube with the plates and solder it top and bottom.
I watered down some all grain strip to 40% then divided it in 2, approx 24l each. got the first charge in the boiler, column with slant plates only, assembled all ready to go .
I made the first run this morning and got pretty much the same results I get from my open column. heads 80% to 75%, hearts 75% to 53% then tails getting oily at about 45%. the tails kicked in about 2% lower than the open column. good clean flavourfull spirit, cut points well defined, volume collected was as close as I cold tell the same as the open column, maybe 100ml or two more.
I then installed the tube with bubble plates on top of the column with slant plates now a total of 900mm, gave it a good clean, 15l of boiling dunder flushed through it a few times hopefully did it's job. charged the boiler with the next batch and proceded to be enlightened.
I collected about 150ml to let the column clear any water fom cleaning, stabilize etc. then stuck the parrot under it 86%, cool got an increase here, collected heads till around 80% then started collecting in 400ml jars, when I swapped a jar over at 78% I was surprised that there was only a slight hint of heads in what was coming out of the parrot, kept hearts from 77.5% let the run proceed and started taking more notice again at about 60% got to 55% and no sign of tails, got to 50% and still no sign of tails, got down to 45% and I was thinking I was screwing up, tails were evident at 42% nice clear tails to 36% then shut it down as it started to get oily/opaque.
So I will end up keeping from 77.5% down to 43%. so I figure the start of the hearts is higher in abv because of heads compression and a more defined cut point with less smearing and the tails, well what can I say, giddy up

it is stripping a lot more alcohol out while compressing and holding back the tails.
This has given me a 20+% gain in drinkable product, still have the full flavour profile and the cuts are more defined.
I can see I'll be making some more bubble plates soon and see what 6 or 8 will do on their own. will keep you informed.
Cheers,
MM.