How hard it is to separate the iron blades of a working iron core transformer? They are glued... any way to release them?
They're not to bad to get apart.
Putting them back together correctly is the hard bit.
If you DIY it they will always end up with tiny gaps and hum loudly when energized.
So i don't recommend rewinding EI cores unless you have the proper gear.
Toroids on the other hand are awesome but have the disadvantage of taking longer to wind by hand since you have to keep threading wire through the center hole for each turn.
Are you in Auckland, you can have that 70x33mm toroid if you want.
I dunno if its the right wattage for what you want though.