I don't have any friends who make ecig oil vaporizers, they all just grow weed. The photos are some shit I found on the webs, as the ones I tore down went in trash.
You are full of shit, and your cartridges are nasty and unhealthy. The oil reserve sits in contact with plastic, solder, and pvc wire casing (which all emit toxins at relatively low heat). Silica seems like a fancy way to say fiberglass, both of which I don't care to inhale at any temperature (much less charred/burned).
There is no 'unwanted crap' in my concentrates, nor left behind on the screen if vaporized by convection. That wick in the photo is all shit-brown and burnt because it's B-U-R-N-T. As in oxidized, converted, toasted, ruined, harsh-to-smoke (cause that's what it's gonna do - smoke not vaporize). None of these should be called vaporizers, not even the thermovape oil models (although at least they have safe components and can be controlled to avoid excessive burning with some dedicated practice).
The thermovape convection models are a different story, cleaner method for sure, but not as practical for oil/wax without slight mod (screen stack as a platform for the concentrate). Most people are probably okay with the burning part, and admittedly it is minimal, but there's just no excuse for unsafe materials. Save that issue, the main problem I have is with continually heating up to a gram of your oil reserve, over and over, every time you hit the thing, mmm. Makes the oil get nasty like what you see in that photo, also pre-decarboxylating it (which makes it less stable and break down quicker). You guys ever smoke resin scraped from a pipe, good shit eh? Payin premium for that at the dispo are we?
Swing your nuts on this, bitch. I paid you $50 for carts which I then filled with winterized bho of known high quality. I even went so far as to buy several different resistance options to test. I read your detritus elsewhere but decided to give them a try anyway (wishful thinking, desperate, in pain). Just how young do you think i am? Are you like a fucking yoda or something?
Your shit is an insult to anyone trying to maintain their health. Get the fuck out of here with your spammy bullshit, swinging on your nuts, what the fuck..