This is to address the taste issue, right? The 'test each cart' confuses me a bit (sounds like it's for heater issues or something you can easily test?)
You know this never made any sense to me (how can that be a problem when the tank top vents to the top of the flue, shouldn't the pressure on both sides of the seals drop together?). Then I realized the missing idea is the concentrate forms a plug of sorts on it's top that effectively seals it off. When you honk really hard on it the pressure does drop on top of the tank with the pressure inside the furnace, but there's liquid concentrate trapped in the tank under the 'plug' that's still at normal pressure, that's where the pressure difference to drive the leak comes from....it has to be real as they sure can leak from this sometimes.
OF
The Taste issue we are tracing back to high voltage, At this voltage the heating wire oxidizes really quick, and sets into the silica rope. As apposed to the 3.7v which takes a while.
Looks like it was not a single issue but two different issues.
The first issue was machine oil taste, and we did have a few cartridge shells that did not get washed, but the second issue we are having looks like its on high voltage device only. IE 4.0 ohms and 5.0 ohms.
Many people without knowing are complaining of bad machine oil taste that is not, it is just the heating wire oxidizing and setting into the silica rope.
We are working to remedy this by actually pre using the heating wires so they are fully oxidized before we manufacture them so the taste is gone before they hit the consumers hands.
So a recap of that is going on.
Few people complained of bad tasting cartridges on the omicrons. Yes we did have a bad batch. All is gone and new items are washed twice, and put into a autoclave twice before being transported into a clean room for assembly.
Second issue that was mistaken to be part of the first issue of bad taste, is attributed to oxidation. this is only happening on the high voltage model that is noticeable in large quantity, this also happens in low voltage models, but it takes longer time for it to happen and it is so small that it is barley noticed in the taste, The heating wire is oxidizing and setting into the silica rope. Nothing to be worried about. Taste goes away after a few hits. You can dry run it but be careful to allow cool down periods in between dry hits.
This update we have, we are working on a upgraded cartridge, but this will happen after the herb chamber, nail cart, and herb cartridge ( my kryptonite )
The tank top does vent, but check this issue out, because the cartridges are hand assembled we have not been able to control the tolerance on the position of the top bridge. Given that it can be off by a millimeter or two, that can cause the mouth piece to make a direct seal, this seal now creates suction at the tank side when people inhale, this is why we said take the rubber white round cap off during use.
Now we have made some changes to the future mouth pieces we have coming to accommodate this tolerance and also made a tool that will keep the top bridge positioned at the same length during assembly. The tool will allow current consumers who have older mouth pieces to work properly, and the new mouth pieces we have coming will make sure just in case by act of god, one cartridge bridge is not in the position it is supposed to be will still work because it has a back up feature to prevent negative pressure in the tank.
Hope this explains it all.