I have purchased large aluminum washers, unfortunately I don't remember
where.
You could also build up a flox pad, use a steel washer to make a release.
 Dave


> What is the right washer to use with aluminum bulkhead fittings (such as
> AN832-8D)? There are a couple of places where the nut bottoms out
> because the rib or bulkhead is too thin. The catalogs don't have
> aluminum washers in that size, and I assume steel is a no-no (due to
> galvanic action).
>