Window frames and flagpole in aluminum
If you have problems with paint peeling on aluminum, you can use Ferro-Bet Aluminum Cleanser to prepare the surface before treating it with paint/varnish.
Remove old paint/varnish
Apply Ferro-Bet Alu Cleanser (avoid spills on sensitive areas)
Let it work for about 10-15 minutes
Use a cloth or simular to rub the product into the surface while it is working
The acid in Alu Cleanser will give better adhesion for new primer and paint/varnish