pull out the pulyfil, use the blue foam mod. .2SQinch of the foam has lasted in a single cart for me for the last 20ML I have put through it. and cost about $.01. not sure how long the polyfil will last, but I find that I don't like the taste of a half empty cart with Polyfil in it. When filling, I take out the foam, fill 80# full, then stick in a wad of blue foam (I cut mine so they only go about 1/4 inch deep into the cart) then drip about 3 drops into the foam to make sure that it is wet.
If you fill it all the way full, when you push it into the atomizer, the atomizer will push the foam in a little, and cause a leak.
as for the physical cart, I have never had to replace one. just rinse it out with warm water. they will eventually wear from being inserted and removed, but I suspect you will get at least 100 refills before that happens.
as for the atomizer, if you properly clean and maintain it, it should last a very long time. I had a joytec 510 cart last 3 months, and even then I sold it with the
batteries in working order.
I like to clean my atomizer with these steps. (about once a week, or when it tastes like it needs it)
1: blow it out
2: do a 10 sec dry burn, wait 30 sec, and do 1 more dry burn
3: fill a shot glass with water and microwave it till it boils
4: drop in the atomizer and soak for 5-10min
5: plug a syrenge into the cart size, and draw in and out water for about a minute. rinse with clean warm water
6: blow out the atomizer
7: stick it in the end of a hairdryer on low for 5 min
then drip 2 drops of
juice into the atomizer before connecting a clean cart
