- The rod surface must be checked carefully in order to identify rough spots or small spikes or ridges.
- a non exhaustive list of the causes of the roughness is the following:
- rust
- scratches
- bumps happened during delivery (only for long rods)
- welding spatter attached to the rod due to welding occurred near the piston on site
- spray of grinding due to grinding that took place near the rod on site.
- Sandpaper with too coarse sand paper. For example in case of more pieces piston assembly.
- to identify the defective areas, clean the rod surface carefully from oil and any kind of dirt with a clean cloth and then inspect by hand the roughness and the presence of bumps or ridges. Mark any defect found with a marker. The simple visual analysis is not sufficient either for the tricky situation of inspecting a round rod in the shaft and for the uniformity of colour of the surface of the piston rod. For the visual analysis of the rod in the shat a small mirror can be of great help.
- smooth thoroughly all the flaws with fine sandpaper FEPA P320 -P400 (Fédération Européenne des Fabricants de Produits Abrasifs).
Recheck the rod surface to make sure that everything is fine.