I purchased a cool book on making bird houses. Many of the techniques use hot gun and wax; esp to make rusty exteriors (adding pieces of rust). I assumee this was must work outside and not melt.
I’m thinking there could be a zillion applications for us in applying details to buildings and even to trains.
Of course you could probably just as well calk it with silicone, but still, this seems like a plausible technique
In bird houses the wax provides a “plesant aroma” for the birds. Silicone (etc.) sealants leave behind a very “distastfull aroma” for birds. I have been putting wax on the inside of birdouses (the ones up high, meant for birds, not the ones on the layout,) for over fifty years after the winter cleanout. I have always used bees wax, don’t know what parifin would do as it is oil based. Many neighbors have gotten upset as their birdhouses are empty and mine are always at full occupancy.
I frequently use a hot glue gun for buildings, windows, and trains.
I used hot candle wax to pour over some rocks along side a roadway. This simulated a small spring cascading down the side of the road embankment. Layers of blue, clear, and purple wax were used.