Wicking a 4/40 screw Vivi Nova coil...question

[wesalexleft]

I'm trying my first rebuild of a Vision Vivi-Nova 2.5 tank head. All is well with dissassembly, and making a 6-turn coil with the 32Gauge Kanthal turned out well...looked pretty even. I had read that a double 2MM wick would be perfect, but I'm having a problem getting that much wick through the new coil. I used a 4/40 machine screw with 6 turns. I have some 2MM twisted silica wick. I threaded the wick through a beading needle, but when it "folds" in half to go through the coil, there's just too much wick to go through. After a few minutes of trying, the wick is so frayed and broken, that I wouldnt want to use it. Am I trying to get too much wick through a 4/40 coil? I can easily get a single 2MM wick through, but it feels loose. I thought about trying a single through the coil with another resting on top, but figured I'd ask here first.

Thanks,

 

[dangkhoa02106]

Let it absorb some juice, maybe you need patient hehehe

 

[bosun]

May I recommend experimenting? You can try forming the coil around the wick using a needle to keep it 'stiff' as you wrap the coil. Use one piece of wick through the coil and another on the top. I myself use cotton through the coil which works fine for me..

 

[dangkhoa02106]

Oh, how about an oval coil shape?

 

[Sthur]

Try building a micro coil like a pro tank and use cotton wick. Long enough piece that goes down into the tank half way on each side.

 

[KODIAK (TM)]

I make the exact same build. But I use 4 ply cotton yarn instead of silica. Two strands of yarn on the bead threader goes right through.

 

[wesalexleft]

Ive been wanting to try cotton anyhow, so I think I'll give that a go.

 

[wesalexleft]

I just did another 4/40 coil with 6 turns. I used the 2MM silica wick with one single pass through the coil and another single 2MM wick sitting on top of the coil. this worked, with no leaks or gurgles, but the draw is a bit tight.Easy enough to remove the top wick, so I did that, and it made no difference. I'm running a single 2MM wick in the coil, and no leaks or gurgles, but my draw is a bit tight. I'm not sure how that is, but I didnt "unwrap my twisted 2MM wick, so that may be it. I'm still going to try the cotton as soon as I get some and get it boiled, etc.

 

[wesalexleft]

Double success! Tonight I made another 4/40 screw coil with 5 turns. This is by far the easiest part of the rebuild for me and its actually fun forming the coil. With the 32 gauge Kanthal, I come up at 2.3 ohms...perfect for me. This time for a wick, I went with some Sugar'n Cream cotton yarn. I initially tried two full strands through the coil, and I could tell it would be too much inside the coil. I removed one full strand, frayed the 4 plys of the remaining full strand, assembled, and it's great. I did boil the cotton beforehand and dried in the microwave in 20 second bursts until it was no longer hot afterword. With some paper towel patting in between, it took about 2 minutes total in the microwave. This one is way better than the 2mm silica wick of the other night.
This brings me to my 2nd success. Since I'd just made the silica coil a couple nights ago, which was now out of the Vivi, I wanted to see how easy it would be to remove the silica and re-thread a single full wick of cotton in it's place. That was super easy. I hope that when the time comes, I can just as easily remove the cotton wick, dry burn, and then install more cotton to get more mileage from my coil. I think it should be easy, especially since I can trim a little of the old cotton wick off before removal.