How can I treat or replace steel bolts in aluminum nuts to avoid corrosion?

Question

I have a structure originally built from aluminum extrusion with channels using aluminum T-nuts and steel bolts. Over the years, the steel bolts have rusted, making them prone to stripping at the head and getting stuck in the nut. I'm going to replace a lot of the bolts to get rid of the rust. Worst case, I replace them with bare steel again, and accept that they will rust again over the next decade or two. I would prefer to avoid that. Can I grease the threads or cover the bolt head with plastic or wax or something like that? Is there a cheaper material than titanium that I could upgrade the bolts to? Are there other solutions I should be considering?

PS: The solution needs to be vibration-resistant.

Answer 1

You could try using stainless steel bolts, dip in an anti-seizing compound like "Coppaslip". Under the head use locking washer, a good option is the "Nord-Lock" it is a 2 piece device, 2 washers that have serrated edge on one side and a series of wedges on the opposite side. The serrated edges grip the bolt head and the structure, the wedge faces face each other. They work by tightening the bolt and the wedges lock into each other, to release you first tighten slightly then quickly release. They are reusable and anti vibration, I used these often when I worked in the mines. Try this site for information; http://www.nord-lock.com/nord-lock/wedge-locking/washers/introduction/