Students' positions within the social network of a physics classroom have been shown to correlate with students' sense of belonging, performance, and persistence in physics. Current research in PER aims to understand how different types of active learning classrooms promote the development of students' social networks. In this work, we begin to examine how these networks develop in introductory physics labs where there is typically ample space and freedom for students to interact with their peers and build a community of learners. The primary goal of this paper is to explore the effectiveness of using video to capture information about student networks in this setting. We use two distinct methods of video coding, which we denote as the "scan" and "skip" methods, to capture two distinct types of interactions between students in our labs: interactions between students from different lab groups and interactions between students from the same lab group. We find that both methods are robust and reliable when used by independent coders, supporting the continued use of these methods in future analyses, but that each method has associated advantages and limitations that should be considered along with the research question being addressed. We use these two methods to explore how students' social networks develop over time.