CCT CCT Surface Preparation & Bonding

Question 1

What is the primary purpose of abrading a composite surface before bonding?

Accepted Answer

To increase surface area and remove contaminants for better adhesion

Answer

Abrading removes surface contaminants and increases surface area, creating a stronger mechanical bond.

Question 2

Which solvent is most commonly used for wiping composite surfaces prior to bonding?

Accepted Answer

Acetone or MEK (methyl ethyl ketone)

Answer

Acetone or MEK effectively removes oils, grease, and release agents without leaving residue harmful to bond integrity.

Question 3

What does the term 'peel ply' refer to in composite surface preparation?

Accepted Answer

A sacrificial fabric layer left on a surface that, when removed, exposes a bondable surface

Answer

Peel ply is applied during layup and removed just before bonding to expose a clean, textured, bondable surface.

Question 4

What is the maximum allowable time between surface preparation and adhesive application according to most aerospace bonding specifications?

Accepted Answer

4 to 8 hours

Answer

Most bonding specs require adhesive application within 4–8 hours of surface prep to prevent recontamination.

Question 5

Why is a water-break test performed on a composite surface before bonding?

Accepted Answer

To verify the surface is clean and free of oil contamination

Answer

A clean surface allows water to sheet evenly; if it beads, oil or release agent contamination is present.

CCT - Certified Composite Technician Practice Test