Mister Madness! A friend sent me an email regarding the filler and the information can be very helpful.
I have also tried a couple of cart mods. (See attached file)
For the last month or so I have tried almost any kind of fill, foam, straw and small silicone disc.
The foam is the best, nice taste, almost better than dripping.
But if it is cut too small the cart leeks, and if it is too big it doesn’t give enough liquid and the cart taste bad.
Now I have found some sheds of aquarium foam 20mm thick, from Aquatic products
I´ve found it here in DenmarkJ
I cut a round “cork” 12-13mm in diameter, in that way they are always the same.
If the cart leeks, I cut it 14mm.
The only drawback is, when the foam gets 2 -3 days old it softens due to soaking PG liquid.
When the foam is soft, it release to much liquid and the atty will flood. If that happens I use 14mm.
The other mod I came upon, because my cart always “bubbles” due to condensation.
Several times a day, I had to take it apart and clean the trap, the end piece and the inside.
The mod is simple, remove the trap and drill up the end piece to 5mm or mill a piece of delrin to fit inside the cart.
A 7mm piece of 8mm nylon tube can do the job, but you have to remove the sharp edges.
Now the cart doesn´t condensate much, and if it does occasionally you can blow it out in a piece of tissue.