So how does air get into this thing?
I've tried covering every apparent opening successively, but i can still draw through it. The only opening i haven't covered is the imperfect fit of the glass stem into the body. It wiggles, so air must be getting in.
Draw is quite open, so the airflow is good. But where is it coming from?
Air enters the FATX case through all the cracks and leaks in the case, the button hole, and the mouthpiece hole.
Then it enters the FATX heating chamber, passing between the ceramic oven and the ceramic lid (with a heating wire between them), heating up between these two ceramic parts. Next, it enters the heating chamber from the side openings that are visible in the heating chamber.
And yes, the air entering the heating chamber can pass through the electronic circuit board. I don't want to start a discussion on this, but I'm just stating a fact.
I have already disassembled one of my FATX to study how safe it is in the matter of air contact with electronics and studied its internal structure.
I think most of the air is sucked into the heating chamber from the mouthpiece hole, because the inlet cavity between the two ceramic parts of the heating chamber is at the level of the mouthpiece hole (the air path is indicated by a red arrow). This is why the O-ring that some people put on the mouthpiece may be a bad idea. This way you will block the air flow and it will start to be sucked into the heating chamber through other leaks, and there may be more contact with the microcircuit.
The air practically does not pass through the electronic board, but only glides over it. The microcircuit is covered with a wooden strip, although not completely (the blue arrow indicated the open area of the microcircuit). Therefore, there is even less contact with the microcircuit.
Of course, it is easier for air to be sucked into the FATX from the mouthpiece hole, this is the shortest route. At the same time, contact with the electronic board is minimal, if at all. However, if the elements of the microcircuit emit volatile substances, they can enter the heating chamber. This is absolutely without a doubt.
With the red arrow, I marked the air intake path to the FATX heating chamber.
In general, for myself personally, I calmed down about the safety of the incoming air. Volatile substances from walnut wood are more likely to enter the heated air than something from electronics.
In general, if you cover the open part of the microcircuit with a thin wooden plate (indicated by the blue arrow), then the remaining concerns will go away. By the way, this wooden lining may solve the problem of shaking the mouthpiece. But the question is, what kind of glue should I use to glue this wooden lining, because glue can also be unsafe?