In the railway industry, adhesive bonding is increasingly used as a reliable alternative to traditional mechanical fastening methods. This study investigates the effect of surface preparation methods on the bond strength of aluminium alloy EN AW 5754 using two different epoxy adhesives: SikaPower ®-492 G and SikaPower®-880. To evaluate the performance of the bonded joints, single-lap shear tests were performed using surface preparation with Scotch-Brite abrasive pads and P180 sandpaper. The results showed that SikaPower ®-492 G achieved higher bond strength with increased surface roughness, while SikaPower®-880 performed better on smoother surfaces, indicating that its formulation is optimised for better wetting and adhesion. These results provide valuable insights into the optimisation of adhesive performance as a function of surface conditions.