I have some experience repairing aluminum
square tanks and have used the aluminum
brazing rod on a few occasions. How much it
shows depends on how the light hits it.
My limited experience is, polishing keeps it from
graying. Getting enough heat in the part to get
the stuff to stick is a challenge for me. If I
can overcome that applying solder would make
getting a level surface much easier.
I saw your gas tank repair last week in projects
and got me motivated to start on this one I
need to get done. Didn’t last long though as it
been sitting on the floor ever since.
Tubs
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.