Have you tried Tapepro flat box bead guides? They mount to the sides of your flat box just behind the blade and give you a reassuring guide when boxing external corners. The inner bead simply compresses against the wall.
Give yourself an edge over the competition, get some Bead Guides!
Durable Stainless Steel guides
Unique torsion spring action
Inner guide compresses against wall
Angular deflection of outer guide ensures no scraping on adjoining surface
Fits all Tapepro, Blue Line and Premier flat boxes.
Can also be used on shadow bead.
