Wow! Thank you so much. I will sit and Reed about it. Very helpful.Steam engine is a online calculator for coils
https://www.steam-engine.org/coil
Enter wire type, inner diameter, and target resistance you want and it tells how many wraps you need and recomended wattage.
For example if you enter kanthal a1 wire type, 28awg thickness/guage, inner diameter 2.5mm and resistance 1ohm
It will show you need 5 wraps of wire around a 2.5mm coil rod for a 1ohm coil and recomend 12w power. Wich is what I use for mtl.
Thicker wire or less wraps will make the resistance lower, I always try to get 5 or 6 wraps
4 wraps of 28àwg kanthal or 6 wraps of 26awg kanthal will be around 0.8ohms
I am looking at the same time for a tank with 0.8 hole as well . you are brilliant