Using timesert for thread repair in cast aluminum

[KiwiKen]

Hi,


I need to use a timesert to repair the threads for the lower unit oil plug on my 20HP 2008 Mercury outboard. According to Mercury Customer Support this plug is made of zinc plated steel and the lower unit is cast aluminum. The timesert kits come in zinc phosphate plated carbon steel or stainless steel. My first thought was to go stainless but then I was wondering if this is a bad idea from a galvanic corrosion perspective. I am not sure this is even an issue for this usage since the timesert should not even contact the salt water.

Can anyone offer advice on which would be the best option? Zinc phosphate plated carbon steel or Stainless steel?


Thank you,
Ken.