Help with upgrade to CCVM reflux

[dmw_chef]

hi folks -

I wanted to get a sanity check on upgrading my pot column to a reflux column. I think searching around and reading old threads has led me down the correct path, but reading through old threads can also be quite confusing and what was considered best practice 10-15 years ago may not be now.

From the start I intended to eventually build my column into a CCVM, so the whole thing is build from triclamp parts.

B - A
|
C
|
D
|
E
|
F

A: triclamp elbow and 2" 45 CM shotgun condenser
B: Triclamp T with cap on top
C: 80 CM spool, packed with a couple copper mesh rolls
D: Plate with large perforations
E: 2" to 1.5" reducer
F: Anvil Foundry 10.5 gallon

To complete my upgrade, I believe i will need the following parts:

G: Coil condenser (thinking https://www.olympicdistillers.com/shop- ... -condenser)
H: Instrument T with a thermowell
K: triclamp sight glass section

So my column becomes:

G
|
B - A
|
H
|
K
|
C
|
D
|
E
|
F

I know that the sight glass and thermowell aren't strictly necessary, but my searching seems to indicate they're helpful especially when learning.

The big thing I'm having trouble figuring out is the amount of packing I will need. My original inclination was to go with stainless SPP (thinking https://www.aliexpress.com/item/3256801207615371.html?), but I've been seeing in my searches that folks are having equivalent results using lava rocks as a column packing. The price difference, and not having to wait two months for shipping make this very attractive.

Can pre made lava rock gravel be used for the packing? (

I've been having trouble finding a definitive answer as to how much packing (either SPP or lava gravel) I should have. I know that completely filling my 80 CM spool is overkill to a ridiculous degree, so my plan was to use enough copper mesh rolls to have the top of the packing layer (SPP or rocks) to be 1/2 to 3/4 up the sight glass.

Can anyone shed some light on how much of either packing media I'd need?

Anything I've forgotten?