Salutations Satyrday,
About "candle" vs "jet" flames, learning curves vs combustion, etc... After 3 months i can conclude i've made progress in 2 areas: 1) my PVC articulated extension makes a significant operating difference; 2) a shield obstructing the focal point will effectively delay "Hot-Spot" formation and hence combustion ultimately.
It seems to me that eye-contact with the front puck and the flame helps a great deal while having a decent refillable butane lighter proves to be quite appreciable as well. I favour "candle"/"jet" compatibility but i'd most probably want to switch instantly should my "2-Stones" wooden pipe be able to handle that... At the moment a pair of 3 mm thick "Ceramic Filters" is coupled to a pair of shielding spacers, combustion has become a much lesser concern but i still need improvement on airflow restriction - but at least i think this solution has real potential. Well, that would be nice already if resellers kept "foamy rocks" in stock besides the VG pipe so lets not be over-optimistic over this one!...
Anyway, i'm also conducting parallel tests using an "Easy Mod" as my reference. The PVC extension remains prefered as i don't like how hot a genuine VG duck-lips mouthpiece can get... It's refered to as being "easy" because this other modification was done
externally, via the sphere's bowl-side access hole: an aluminium "defocussing" shield can be conveniently added to deflect radiating heat while a screen keeps this section clean (it's still possible to leave some free space if i want):
Though i'm afraid that's no definite Combustion Fix just yet - but there's hope!
N.B.:
That "Shielding Spacer" left a dark image on my ABV, i need to make more room between it and its corresponding screen as fairly intense heat emanates from there...
...
Alternately my "2-Pucks" approach appears to lead to a suitably-balanced deal but it's going to prove tight on space. If i'm right thickness must go down to nearly 1 tenth of an inch for each puck since my aluminium sheet seems close to AWG #19 and i'm assuming the use of assymetric spacers with legs on 1 side only (twice the thickness for the middle shield). An untouched genuine puck is about 7.5 mm thick, in comparison this structure should fit nicely with ~0.6 mm to spare (1 pair of pucks seperated by 1 spacer, the other being located in the externally-accessible bowl-side part of my sphere).
So far i notice my ABV gets darker and yet it looks more even, which i view as an indication that deeper extraction effectively occured (and i see no scorching under normal conditions). There are 2 heating methods, as usual or "
Red-Hot"... Getting some better airflow is all that's left to be done i believe. Combustion is no major concern by the time a bowl gets spent in any case.
Also, having recourse to the extension tubing allowed me to "climb the curve" at my own pace so i can now operate a genuine Classic wooden VG pipe
if i must.