I was looking closer at my Colnago last night and looked under the TT. I see a few places where there is rust under the paint (light bubbling of the paint), and a spot or two where the paint is gone and you can clearly see rust. On top of the TT at the cable guides is a small amount of what could also be rust under the paint. This isn't a rust bucket like I've seen on some rides here on this forum. I live in a very dry climate here in Phoenix, AZ. Would you ignore it, try to do a refinish of just the TT, or go ahead and strip and paint the whole frame with new decals?

I would not repaint that bike......... Touch it up with some same color, or clear nail polish and ride on............ If you like you can take some light sandpaper and clean the area up first the touch it up.

It's black, go to the hardware store, get the smallest paint brush you can, some sand paper and a small tin of black tremclad or rustoleum rust paint. Where you have bubbling paint scrape it off, then sand to bare metal, then carefully brush on the rust paint, consider it fixed. For things like cable stops, you may need to remove the cable in order to repair it properly.

Are you serious? DO NOT repaint that bike! And DO NOT rough up the paint with sandpaper unless you plan on repainting (which you should not do).

Any rust can be taken care of with an Oxalic Acid bath if you're seriously concerned about it. Just do a very low solution and soak it for 24 hrs, it should take care of it. After that, you can touch it up with Testors or some other hobby paint, or just treat the frame with some sort of rust preventative. Boiled Linseed Oil works well.

Thanks for the reply's. How do you use the boiled linseed oil?

OA bath will ruin the paint even with a small amount of OA. The paint will become dull and even a good waxing will not bring it back. You have just some very tiny spots, and a tiny piece of sandpaper followed by a cleaner like Acetone and dried will be pefectly fine. You can then touch it up with clear nail polish or paint of the same color.

You soak the inside of the tube with linseed Oil and let it air dry. This will prevent further rusting from the inside out.

OA doesn't, but naval jelly clings, so you can apply it to just the rust spots. it's phosphoric acid, i believe.

Thanks all. Seeing as how the most effected spots are on the underside of the TT, I think I'll flake off the bubbled paint, get the rust off, and repaint / seal it. No one would normally see it anyways as it is the bottom side. I first noticed it because I lifted the bike from the TT and noticed it felt a little rough. I'll ignore the little bit around the cable guides... it is almost 30 years old after all.

Tell me more. How many painted frames have you treated with oxalic? What concentration? I have done about 40 frames so far, haven't ruined the paint yet. But I use really dilute oxalic.

But I do not recommend an oxalic acid soak for just a couple of minor spots. Not worth the effort, and there are spot treatments you can use instead.

I've done a few frames and all three ended up with a milky dull finish. I used 2 TSP per gallon of water and soaked overnight. The frames were rinsed with tap water and left to air dry. As far as I'm concerned it should only be used to treat the inner tubes. Lots of others on here have had the same problem with the dull paint issue.

I am going to treat the the inner tube of a frame I have to see how it works out. I have 3 rubber expandable freeze plugs, one for each side of the BB, and one for the lower cup of the Head Tube. I am going to hang the frame level and pour the solution into the seat tube, and head tube until the main frame is full. The stays will be done the same way by blocking the drain holes with small rubber plugs.

Your paint dullness is a result of rinsing with tap water. You need to use a water/baking soda mixture (or similar) to stop the chemical process. Regular tap water with not stop the chemical reaction of the OA.

What is the water/baking soda ratio for a proper rinsing solution?

+1
curious as well
useful thread

I go on the extreme side of things. I get a nice amount (couple gallons) of water and add baking soda to near saturation. Meaning, I add and stir in baking soda till it takes 15 seconds of stirring for the powder to dissolve completely in the water and become clear. You could possibly get away with less, but for less than $1 per box of baking soda, I play it more safe than sorry.

So in theory, I could remove the paint in the rusted area of the top tube, place the frame upside down in a wall paper tray in a OA soak of the TT, then rinse with a baking soda soak the same way, rinse with fresh water... and have no paint discoloration? Then just touch up the paint as needed.

Just curious as I'm learning. For this issue however I think I will just physically remove the little rust under the TT and touch it up.

I still wouldn't soak that frame. Just work with tiny bits of sandpaper and focus on individual areas. Yours doesn't require a soaking IMO.

+1 Need to neutralize the OA with baking soda. Mix is not that important, as you should only be neutralizing what is left on the frame or part, not the entire bath. I typically just make a slurry of baking soda in a small bucket, and use a sponge or rag to wash the outside of the frame, and pour it through the various tubes to neutralize what is on the inside. You can buy either an eight ounce or one pound (I forget which) of baking soda for 50 cents at Walmart.