AO Silver Member
Join Date: May 2008
Location: South Africa
County: Western Cape
Presumably you are NOT referring to Liquid Wax vs Paste Wax.
The only thing that determines how "hard" a paste wax is, is the amount of solvent contained in the formula. All paste waxes have to contain solvents as Carnauba Wax in it's natural form is as hard as a rock.
I really wouldn't concern myself with the hardness mate, but rather go for a really good quality Carnauba wax (eg. Meguiars #16, P21S, Collinite)
Ensure that the surface is well prepared - It's 80% about preparation and 20% about Wax
4. Wax - to provide a good protection