Classic & Vintage - Rust from within?

I've a 1978 Romic Road Bike w/ Reynolds 531 tubing w/ chrome chainstays and forks. There is a two inch X one inch slash / completely rusted through on the underside of the top tube !?! and multiple bubblings scattered on frame that I guess are also from rust on the inside? Spots on crhomes from my body salts? that are rusted.

How to repair the top tube? Any thing to do about the bubblings on frame? Any thing to do about the chrome stays and fork rust spots, pls?

If it's rusted through completely the tube will need to be replaced. Take the frame to a good builder for an assessment. If other tubes are in similar condition it may be a lost cause.

My wife found a "beater" Schwinn of undetermined model (no decals and all the components had been replaced). Little rust spots and bubbles everywhere. 15 bucks with bunch of extras. Rode nice so how could she go wrong? Several months later the top tube and the head tube parted company just getting on the bike! Had it happened at speed I hate to think what could have happened. I'd get rid of it myself, but I'm a cowardly type.

Don

+1 Typical donor bike. Find a replacement frame, or just strip the parts for future use.

Under the top tube is one of the worst spots for rust, water and sweat settle there. It's also death on bikes that sit on a trainer.

Time for a new frame. Or a very pricey (like new frame expensive) repair.