Vito, I hate to say it but you are wrong this time. The vapor airpath flows as Vaporeyesore stated and does go past the quarter sized bottom part of the concrete cup, then back up through the center hole of the heatport and around the ceramic heater where it is heated to the final heat stage before moving through the stem tip contents. In the traditional design(not the TT), that area is wood. That is where the charring starts in the traditional log vape design.
We have convinced ourselves that pulling warm air over a small circle of cured, baked concrete is safe because the concrete is cured or 'sealed' to the consistency of a rock. No concrete dust as it is cured. Just a rock liner but we make the rock.
Having said that, we have already instructed the machine shop to get us a quote on installing a SS flat washer on the very bottom of our current design as Alan(TV) has suggested because he does that in his design. That will make the safety of cured concrete a non issue as the entire air path would be totally enclosed in Stainless steel. That bottom sealing washer would then be electro polished with the entire assembly as the last step in the process. I will report later today on that subject.
We will also be picking up the mold for the liner cup today so will be making good progress in that direction.
A handful out today. I surprised myself even, rockin to the oldies til 10:30 last night.
With regards to any safety issues about our products or soon to be products, please remember we have been through some serious challenges here on FC over the past years regarding the safety of brass. We take the safety subject very seriously because we know the questions will come, as they should.
Elton, I refer to the concrete liner as a 'rock' because cured concrete is a type of rock. Yes, a man-made rock.
Alan, thanks again for your help. A totally sealed SS Airflow is the bullet-proof design that covers the safety issue thoroughly.
Vito, sorry about that. Look a little closer........