Screwdriver: Works and then doesn't

[Wings]

A few days ago I got the Screwdriver e-cig device (the model II). I mixed my own stuff and for the first few cartridges it was fantastic. Lots of vapor and a good throat hit. But now, a lot less vapor, and sometimes none at all. And sometimes a harsh, dry puff followed by one that is very normal. I'm confused at what may be the cause and any suggestions offered would be appreciated.

I'm mixing 50% TotallyWicked 54mg Platinum Ice, 25-40% propylene glycol, and the rest is menthol flavor concentrate. I've tried both atomizers that came with it and different cartridges and nothing seems to provide a consistent result. For example, right now I took a puff after the Screwdriver had been sitting for 20 mins or so. First puff had a good hit but very little vapor. 2nd puff was a little harsh, and 3rd was awful. The 4th was back like the first puff. Waited 2 minutes, and the 5th was harsh & dry. The 6th had little to no vapor and no throat hit at all, like smoking nothing. Likewise the 7th. I wiggled the wadding around with some tweezers to verify it had liquid in it and tried again. Good hit, medium vapor on puff 8. Puff 9 was back to harsh & little vapor.

What's going on?

 

[prof beard]

If you take the cartridge out and press the button is the atomiser heating up normally (showing a nice cherry-red glow)? If that is happening reliably with both atomisers the SD itself is fine and the problem is at the cart end.

The carts you got with the SD - are they the two part 901 carts (with a black main section and a brown bit where the filler goes) or the one-piece black ones?
(Or did you get a mixture of both types). Normally, TW supply RN4075 atomisers with the SD and they work best (in my experience) with the two part ones.

What you describe sounds like the cart isn't wicking onto the atomiser properly (and possibly the carts are a bit dry).

(I assuming you are filling the carts properly etc of course)