I plan to attach some aluminum (6061) to an existing aluminum chassis of a trailer (vehicle), using stainless steel bolts, washers, nuts. The vehicle will be subject to road spray and weather.
I'm aware that galvanic corrosion could occur, but is less likely due to the volume of the stainless steel being much smaller than the aluminum.
To further reduce the risk of galvanic corrosion I could add non-conducting washers between the aluminum and the stainless steel washers. However this adds a new risk that this washer shrinks or dislocates, removing the tension in the bolted joint.
Given that trade-off, is it net-beneficial to the reliability of the assembly to add that non-conducting washer, assuming a 30 year intended life span.
If so, what material is recommended? Nylon can swell when wet, so I'm ruling that out. I see washers available in: PEEK, Polyimide, phenolic resin
thanks
