Don't for whatever reason cap off plugs or weld 7075 standoffs to any other 7075 parts or assembly. Don't do test welds, or any samples, or first articles, or anything else. Don't even try. Sorry for offering any type of reply. P.S. Never, ever, under any circumstance try to anneal, bend, weld with 5183, and retemper 7075 to original hardness.