## 4 Conclusions  
Based on the comprehensive corrosion-mechanical assessment of the test samples, the highest coating quality for both electrolytic and hot-dip zinc coatings was achieved using conventional zinc coating methods that exclude mechanical pre-treatments from the process. This can be attributed to decades of development and refinement, which have optimized these conventional methods to their current level of effectiveness. However, a major drawback of conventional technologies is their reliance on chemical pre-treatment processes, which involve the extensive use of chemical substances. From an environmental and sustainability perspective, it is therefore essential to explore innovative alternatives. One promising approach is the partial replacement of chemical pre-treatments with mechanical surface preparation methods. The experimental results indicate that, with proper optimization, mechanical pre-treatments can produce high-quality zinc coatings. For both zinc coating methods, grinding emerged as the most suitable pre-treatment, as coatings applied to ground substrates exhibited corrosion-mechanical properties statistically comparable to reference samples. Conversely, the least suitable pre-treatment was blasting with angular synthetic corundum, as it induces significant structural inhomogeneities in both coating types. These heterogeneous regions ultimately accelerate the corrosion degradation of the zinc layers. Compared to synthetic corundum blasting, steel grit blasting appears to be a more suitable alternative. However, a notable drawback of this method is the high hardness of the subsurface layers, which increases substrate brittleness and negatively impacts the ductility of electrolytic zinc coatings. As demonstrated by surface roughness analyses and metallographic evaluations, the spherical shape of steel grit particles provides a favorable surface microgeometry. To further optimize the blasting process, future research should focus on the following:  
* Selecting spherical particles with lower specific density.
* Reducing subsurface hardness through appropriate heat treatment.  
Such an approach could mitigate the negative effects of mechanical pre-treatments while preserving the benefits of alternative surface preparation methods.  
Conceptualization, J.L. and J.V.; methodology, J.L. and J.V.; software, A.P.; validation, A.P. and J.V.; formal analysis, V.K.; investigation, A.P., J.L. and J.V.; resources, J.L.; data curation, J.L. and A.P.; writing--original draft preparation, J.L.; writing--review and editing, J.L., V.K., J.V. and A.P.; visualization, A.P.; supervision, J.V.; project administration, J.L.; funding acquisition, J.V. and V.K. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Internal Grant Agency of Mendel University in Brno, Faculty of AgriSciences, grant project No. AF-IGA2022-IP-004.  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.