  Radiopure materials for detector components in rare event searches may be
contaminated after manufacturing with long-lived $^{210}$Pb produced by the
decay of atmospheric radon. Charged radon daughters deposited on the surface or
implanted in the bulk of detector materials have the potential to cause
noticeable backgrounds within dark matter regions of interest. Understanding
the mechanics governing these background signals is therefore a paramount
concern in dark matter experiments in order to distinguish a real signal from
internal detector backgrounds. Teflon ($i.e.$ PTFE) is a specific material of
interest because it makes up the walls of the inner detector of many liquid
noble detectors such as the LUX-ZEPLIN experiment. The rate of radon daughter
plate-out onto Teflon can be orders of magnitude larger than the plate-out rate
onto other materials. Mitigation of plate-out onto Teflon and steel by
proximity to other materials is demonstrated.
