TY - GEN AU - EF Hickson AU - WC Porter C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1946-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.LCIRC.831 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1946 TI - Letter Circular 831::the painting of exterior metal surfaces (superseding Letter Circular 422) ER -