First of all, I read a lot and tried several times, with many fails. The most important is boil them a lot. Most people said boil them 3 times, 20 mins each. I boiled them once and did it several times, fail. The last tried, I boiled them for 20 mins or so, squeezed them dried, boiled them again. Keep going for 4 times. then squeezed them dried and let them sit for several days until they were completely dried.
Roll the coil as usual, roll the cotton ball in my hands/fingers until it is tight in a tooth pick shape. When you roll it, the middle section should be bigger and tighter than both ends, automatically archived. Slide it through the coil. When sliding it through the coil, the middle section should stick tight to the coil. If not, slide it out and start the rolling again. When the wick stick tight to the coil, you can trim both ends. Install everything together.
Several first tried, taste and smell a lot of cotton. I read again and found that I should prime the wick after installed, and let it sit for several hours. I did let it sit over night. The morning, I vape it and found the diff. After couple puffs, taste/smell even better than the original silica wick. Strange thing is that now even when I have new coil/wick, I vape right away without letting it sit, but no bad taste/smell after couple puffs.
There are a lot of threads people talked about this process on this board.
Good luck.
Can you describe how you build the cotton ball wick?
Thanks, Tom