I am interested in hearing first-hand experience with using a product called Tef-Gel, frequently sold by marine retailers for use in reducing or eliminating corrosion between dissimilar metals, such as a stainless steel machine screw threaded into an aluminum boss or tapped hole. I don't have any familiarity with this product. It sells for about $15-per-ounce.
For background on Tef-Gel see:
https://www.tefgel.com/contain.php?param=tefgel_infor#
TEF-GEL
Re: TEF-GEL
I like it for the stainless steel bolts used to mount aluminum outrigger bases,and lower unit bolts. The ss bolts on the aluminum trailer also. Lots of places on a boat, motor, and trailer used in salt water.
Chuck
Chuck