Tony, that was also what I always thought should be done But apparently, only you do this - as far as I know other commercial 'liners' do not apply any protective coating. Best wishes from Tokyo, Zubi
As far as I am aware, I believe you are correct. I am happy to be corrected, of course.
What would be the need for a 2nd coat of clear? Both are enamel, one is clear one (the lining) is colored?
Jason, I'm not sure what you mean by a "2nd coat of clear". Roundhouse locos do not have a clear coat applied. And there is no "enamel" paint used by them or me, just two component automotive acrylic. The paint system I use is as close (it may even be identical) to that used by Roundhouse as I can achieve. Same primer, same paint type, etc.
The lining paint I use is durable, but over time it is not durable enough to cope with heat, oil, frequent wiping, frequent handling and general wear and tear. Ideal for a Shelf Queen, but not for a working steam loco. It is always reassuring to see a loco as good now as it did when it left my workshop several years ago.
Each loco is reduced to its component parts for lining, and each is handled separately. Only those parts receive the clear coat, and definitely not the polished brass, running gear and the rest. You are correct in saying that masking is not (usually) enough. For example, repainting a Roundhouse Darjeeling B-Class boiler from incorrect light blue to the correct black (blue and green Darjeeling B-Class locos have black boilers, and red ones have a red boiler) requires removal of the boiler from the chassis, so also requiring removal of the body, tank, smokebox, radio control, gas system, and so on.
I have a Garratt on its way to me and I have already discussed with Roundhouse how to dismantle it sufficiently for the work I am to do, and I am grateful to them for the advice they gave me.