In my model i Use to sold white metal parts.
They are fixed well ,simple to sand by files and ,overall,Has got the same surface of the rest of the model.
It's Very helpful way when i have to devided 2 flaps of the same wing.
I sold the edge with a small line of solder then i sand it up to correct shape.
Easily strong and fast!
p.s For ur information.....The guy is AKIHIRO KAMIMURA and he wrote On F1 MODELING Magazine....
I named him The MASTER MODELER!!! Now u Know y!