Unfortunately, I'm old enough to have gone through this process; learned it when I was a young teenager. First rough up the rim surface to be coated with shellac. Use a heavy 4 lb. cut shellac (a high ration of crystals to alcohol) and build up two or may be three layers on the rim. The tire base tape should be latex free but I never gave much attention to that. Mount the tires when the final coat of shellac is still wet. Pump up the tires and set the wheels out in the sun for a few hours.
Michael Allison
New York, NY