Nine commercial rust converters and tannic acid were evaluated for their abiility to form stable coatings on corroded iron artifacts stored or displayed outdoors. The rust converters were analyzed for significant chemical components using scanning electron microscopy/x-ray spectrometry (SEM/XES), x-ray diffraction (XRD), and Fourier transform infrared spectrometry (FTIR), and in general contained tannic acid and a polymeric consolidant. They were applied to pre-rusted 10 cm x 30 cm mild steel plates, and were tested without application of a top coat of paint. Two test methods were used:i) a 30 day saline spray test (accelerated ageing), and (ii) up to 5 years of outdoor exposure in the prairie, central, and maritime regions of Canada (natural ageing). The most rapid and severe degradation took place in the maritime climate, and the least severe in that of the prairies. After combining the results from the saline spray test and outdoor weathering, the rust converters with best overall durability (and which are still available) are Conquest Polymeric Rust Converter and Rust-Oleum Rust Converter 7830. These coatings will protect the iron surface from re-developing rust for several years in most outdoor environments. Other products included in this study may offer excellent protection in some environments. -- CCI