What's the difference between spray, powder, spray paint, and electrophoresis? If these surface treatments are used in door hardware, what are their respective advantages and disadvantages? Described in terms of adhesion, surface hardness and salt spray tests

Spray and powder are both types of coating applications. 

Spray is a liquid coating that is sprayed onto a surface, while powder is a dry coating that is applied electrostatically and then cured with heat. 

Spray paint is a type of spray coating that is specifically designed for painting surfaces. 

Electrophoresis is a process where an electric current is used to deposit a coating onto a surface.In terms of adhesion, powder coatings typically have better adhesion than spray coatings. 

Spray coatings can sometimes have issues with adhesion if the surface is not properly prepared. 

Spray paint can have good adhesion if the surface is clean and dry. 

Electrophoresis can also have good adhesion, as the electrical current helps to bond the coating to the surface.

In terms of surface hardness, powder coatings are generally harder than spray coatings. Spray coatings can be softer and more prone to scratching. 

Spray paint can vary in hardness depending on the specific product used. 

Electrophoresis can also have good hardness, depending on the type of coating used.In terms of salt spray tests, powder coatings usually perform better than spray coatings. 

Powder coatings are more resistant to corrosion and can withstand longer exposure to salt spray. 

Spray coatings can sometimes fail the salt spray test if the coating is not thick enough or if the surface preparation was not done properly. 

Spray paint can also vary in its salt spray resistance depending on the product used. 

Electrophoresis can have good salt spray resistance, but again, it depends on the type of coating used.

Overall, the advantages and disadvantages of these surface treatments in door hardware depend on the specific application and the desired outcome. 

Powder coatings are generally more durable and resistant to corrosion, but they can be more expensive and difficult to apply. 

Spray coatings and spray paint are easier to apply and can be more cost-effective, but they may not be as durable or resistant to corrosion. 

Electrophoresis can provide good adhesion and corrosion resistance, but it may not be suitable for all applications.