TPB coating equipment and methods for the COH-Ar 750 detector.

COH-Ar 750 is a ton-scale liquid argon detector, currently being assembled to be deployed at the Spallation Neutron Source at Oak Ridge National Laboratory as part of the COHERENT program. The use of tetraphenylbutadiene (TPB) as a UV to visible wavelength shifter is a common practice for noble gas detectors. In development of COH-Ar 750, we designed and built an evaporator with a "planetary orbit system" to ensure a more uniform coating of TPB on PMTs and PTFE panels. In this talk, I will present our coating methods along with results from quality tests of samples.