Oldairhead 

I've got this bike, a 197? Legnano Gran Premio and was trying to decide how to proceed with getting it back to riding condition. It had a serious case of rust blistering up in the paint but I didn't want to do a "like new" repaint on it. Overall the paint didn't look awful except for those spots of rust, perhaps 5% of the frames total surface. I thought I would try something new (for me) on this one so here is what I did. I scraped off any loose and blistered paint to bare metal, then I treated the affected areas with naval jelly. Next I sanded those patches with a fine sandpaper to taper the edges of the paint to a smoother finish. Finally I sparayed it all with clear laquer to protect the areas of bare metal. The result is a finish that retains most of the original paint but I have stopped any further deterioration of the paint and the metal. The flaws are quite obvious but seem to add some character to the bike. The targeted result for this bike will be a period correct rider, not a museum piece. It will be used in Century rides and shorter brevets, perhaps 200 and 300 km distances.

I am curious if others have done something similar to "arrest the decay" but try and keep the bike original?

echo

Not sure how long clear will stick to bare metal, I think I would of used a little primer on the bare metal, then try to find some touch-up paint that matches or comes close to matching the original paint. A steady hand and you can do this with a decent quality paintbrush of appropriate size.

Chris_in_Miami

I've done something similar, but I tried to find a reasonable (but not exact) match to the paint. It looks good from 10 feet, but up close it's evident that the condition is not great. I hope it doesn't look like I'm trying to conceal the flaws. There was a big ugly bare patch on the top tube, now there's a big ugly mismatched patch, but it's not rusting!

Oldairhead 

It is a bit of an experiment. The damage has already been done where the bike lived previously. If the laquer takes, I hope that it will not get worse. I will have to wait and see I guess!

Italuminium

When it works, it's a great solution to the keeping patina/repaint dilemma. I look forward to see this beauty in october! And nice campagnolo sign on the wall, btw

phillyrider

I did a touch up to one of my bikes, and regretted it. My preference is to something similar, remove the surface rust then cover with clear nail polish. It works ok.

Ex Pres 

Have to say when I've had a frame in that condition and don't want a full repaint, I'll still look for a spray can to try to match. Once I even used two cans at the same time to mix the colors. It's always hard to guess through pics, but yours looks a lot like "guards red" (Porsche uses it).