If you are using a cart with stock filler, yes that is normal. It takes time to wick. That's one of the main reasons there are so many cart mods, like blue foam, pyramid tea bag and the zero filler mod.
Yes you can refill them, many many times. just wash out the filler before you fill the cart.
I personally use the blue foam mod and I'm very happy with it.
I pour freshly boiled water over the filler pieces to clean them. Pour into a little shot glass for that. Works well with both polyfil and blue foam, really visibly perks them up. I personally use foam because the foam bits can be reused many more times then the polyfil (imho), and just plain delivers liquid better. The polyfil loses its 'fluff' after a couple of cleanings, whereas I have yet to discard a bit of blue foam.
To fill a dry empty cart with foam, I drip into the cart until its almost full, then work the foam bit down into it using straightened paperclip (a very indispensable vaping tool). I drag the foam down by working the clip down the side of the cart with it 'hooked' into the bottom of the foam bit. Adjust by pulling up on the top with the clipped hooked at the top of the foam. Then top it off with a few drops.
To refill on the go with foam, I just compress the foam down a little into the cart with a paperclip, drip into cart, plunge a little with the paperclip, drip some more, plunge, drip, pull the foam back up by hooking the top with a paperclip... done.
Straws and springs and what not are just a waste of time (imho). Foam bits work for every type of atty I've come across.
To prep new foam for use, I boil it several times to get the foamy taste out, and then cut with scissors to the desired size for the cart (roughly 13mm wide for 510/901 carts, and not quite as long).
Marineland Magnum Foam Sleeve "Rite-Size U" 3pk.
Not mucking with polyfil made vaping a lot nicer for me.
Happy Vaping!
