The preparation operations of the support are, as always, fundamental to obtain an impeccable final result.
In this case the iron gate now has a layer of discontinuous paint with exposed parts, so it is not possible to paint directly after a simple sanding. The best solution then is to bring back to the metal and proceed with a new painting.
If the surface to be treated is contained, it is advisable to use a chemical paint remover to be applied with a brush and removed with a metal spatula. In this case, given the extension of the gate, it was preferred to use a mechanical system by means of abrasion with a metal brush applied to an angle grinder.
After a first approach with a cup brush, ideal for flat surfaces, we opted for a circular brush with braided steel bristles. The advantage of this type of brush is the greater stiffness of the bristle which results in a greater abrasive force. The braided bristle also prevents the projection of any broken bristles during contact and therefore injuries.
The disk configuration allows you to reach corners even in tight spaces that has good handling.