Wow!
I just read this thread, and will keep non-relevant comments (to the OP's topic) to myself.
I do own a VL BB, I really like it, and so have everyone of my guests who have seen it.
Like the OP, I struggle with when to add fluid, and when I do, I add 10 drops at a time. The problem is, when to add? Sometimes it smokes a lot, sometimes not so much.
One thing I learned (reading this thread) is that the smoke unit (wadding and heating element) will not be damaged if they run dry. At least this is what I gathered from reading some of the posts.
Relevant questions, I think:
1. How much smoke (time-wise) does a drop or fluid make? This wouldn't have to be precise. For instance, "one drop of fluid at maximum smoke level should produce smoke for 30 to 45 seconds, while the locomotive is running," or whatever the real duration time is. This would be helpful.
2. At what rate does the smoke fluid evaporate when the locomotive is not running. If it sat for one week without running, should fluid be added, regardless? What if it sat for one month? Or should we run it first to see if any smoke is produced after it sat for a while without running? Of course, now we have to define "a while".
3. Wouldn't it be nice if there were a humidity sensor inserted in the wadding, with its output interpreted by the electronics, which would announce "time to add smoke fluid" as part of the crew talk repertoire when the wadding became too dry?
Alex