Re:Secondary Insulation

On the secondary that I pplanning on winding...
There is a recc. insulation thickness for the wire of .024" in order to
handle 3Kv... I can only find Belden up to 1000v...(unless i want to jump
to their super pricey stuff.) If I place a dummy wire between windings, to
space the windings out, then remove it after the winding is done (thus
doubling coil length) will this be sufficient to prevent arcing?
Rob Del Bueno