Thanks for that.Solid is better.
Mild steel and soft iron are not the same. Soft iron has a carbon content of around 0.3 percent or less. Mild steel is around 3 to 6 times higher.
The important factor is the ampere turns figure. By adding wire but you gain a heap of turns. The math needs to be done for current.According to my sipchering the amp draw went down by adding turns. Am i messing up going with bigger coils?