I started learning to build coils when I was still using the T3S's, which were $6 for a 5pk... but about the third time I got one that was a dud right outta the pkg, I said this shit is for the damn BIRDs, and set about learning to rebuild those tiny heads. Someone mentioned that if I could rebuild THOSE tiny things, then a kayfun would be a piece of cake -- and it was! Now, the Achilles has a very similar architecture for the coil-mounting, but even a bit more room to work in, so it's even easier than a kayfun.
But yeah, sometimes I have a coil that just won't die, for whatever reason. It might be because I've gotten kinda lazy about dry-burning, and if the wick looks really brown and dirty, instead of pulling it and dry-burning, I just syringe all the dirty brown juice out of the well just as well as I can, and then bathe the coil and wick in plain PG, for 3-4 rinses, syringing out the brown stuff until what I'm syringing out isn't much darker than plain clear PG... so that even if the coil still looks a bit brown, the wick is back to white, and it's good for another week or so before I need to do it again. That, which doesn't wear out the coil so fast, and the fact that I have my flavoring down to about 23%, so the gunk doesn't build up so fast, really extends the life of the coil. I long ago learned that you can't rinse the wick in water, it just destroys it, but rinsing it with plain PG works really well! And PG is cheap, especially since I buy it by the gallon via Amazon, and get free shipping.
I'm ALLLLLLL about pinching pennies till they absolutely SCREAM.
I did tell my son about my extreme displeasure with him, about switching the PG/VG arrangement, and he was properly apologetic, said he didn't know there was a "precise arrangement." I asked him how long he's known me... almost 31 yrs now? (next Sunday is his 31st b-day!).
He did the same thing once with my bottles of DX Bavarian and Vanilla Swirl, which I always put back into the cabinet in the correct order for mixing -- but fortunately those 2 taste so similar that flipping their recipe amounts didn't make much difference in the taste of the finished juice; I use both of them because the DX Bavarian starts tasting vomitous if you use more than 6%, which was the amount of DX Bavarian in the recipe in its initial incarnation, plus 4.5% of the Vanilla Swirl; they're now down to 4.7% and 3.55% respectively.
Andria