I have been making a decorative knife out of 1018 cold roll steel. Because my mill is currently unusable, I cannot make the crossbar out of steel (the design is too complicated for other tools). I decided that casting it out of aluminium would be the next best option. However, steel and aluminium together create a risk of galvanic corrosion. After some research, it seems the best solution would be to use aluminium 2017, 2024, or 2117, since it is very close to 1018 on the galvanic series. I also plan to insulate the two metals with rubber. My question: Will this stop the corrosion?