Structural steels that require coating with pre-construction paints to avoid corrosion are utilized in important industrial segments. These paints, known as primers, act as corrosion inhibitors; however, they can have a detrimental impact on welding performance and compromise the quality of welds. In order to overcome these challenges, new alternatives need to be developed to achieve welds that are, at the very least, equivalent to those obtained on uncoated plates. To this end, this work aim at promoting the production of welds on plates coated with primer and varying concentrations of fluoride added to the base formulation, by means of 1.2mm diameter tubular wire classified as E71T1-C1A2-CS2 with CO2 gas protection. In a comparative analysis, the influence of non-filler primer and primer with 7.5% and 15% by mass of lithium fluoride was examined. It was found that the primer inhibits the adhesion of welding spatter on the plates, affecting the weld morphology and resulting in wider and deeper weld beads. On the other hand, the presence of fluoride tends to reduce the weld width, although it does not appear to affect penetration. It was also observed that the primer does not influence the weld microstructure, as opposed to welds with no primer. The incorporation of fluoride filler increases the volumetric fraction of acicular ferrite and aligned second-phase ferrite, while simultaneously reducing the fractions of primary ferrite at the grain boundary and of intragranular ferrite. Lastly, the electrical signals recorded during welding show that the primer increases the average welding voltage, and the presence of fluoride tends to mitigate this effect. On the other hand, the average current tends to decrease in the presence of the primer, and the addition of fluoride exacerbates the trend. As a consequence, samples with fluoride filler exhibit lower thermal inputs compared to the other samples. Furthermore, the presence of the primer leads to an increased frequency of voltage peaks, indicating alterations in the metal transfer process.