[Nixie]

Is there any problem with using a transformer that has copper foil instead of wire secondary winging for amplifier power supplies? I have a couple rated 950 VA transformers with 15 V secondary that's thick copper foil. I took them apart since I need to wind for different voltage, but I'm thinking if I wind with wire I won't get as much overall crossection with the wire due to gaps between the wires, so I'm not sure how that'll impact performance.