Yes, under this pain job Brian found a 1970 Colnago Super! The sad part is the frame had recently been repainted by a highly respected member of our community. The customer was charged a lot of money for this terrible paint job. To top it off even the decals were incorrect! Buyer beware! Do not ask me who painted it because I will not tell you. Sterling
>
>Listmembers,
>
>Since the topic of painting bikes came up a few days ago I had the
>occasion to observe a few things on a frame that just came in. This
>frame had a recent professional paint job on it and it brought to mind a
>few things that would be helpful for you do-it-yourselfers to know
>about. These points are particularly important on earlier frames where
>there are few or no braze-ons for cable guides (both tt and bb),
>shifters, front der., and pump pegs.
>
>The bike had had parts clamped on but I don't think it ever got on the
>road after the repaint, or if so only for a very short time. In each
>spot where the clamps were located, the paint had "torn" away from the
>primer as the heavy coats of paint and clear were squeezed out from
>under them. Rust would have begun forming as soon as the bike would have
>been used. As Dave Feldman mentioned, the seat bolt and seat post had
>also caused chipping in addition to anywhere the wheels had been and
>where the freewheel had touched the chainstay. None of these things
>should happen to a paint job, wheather new or old. The cause of these
>problems were three things, which I will explain.
>
>First, in an effort to save a step, white primer was used. My experience
>has been that white primer not only doesn't stick to the bare metal as
>well as the grey-green formulation of the same stuff, but paint doesn't
>bond to it as well either. It's better to use the green primer and lay a
>coat of white down before the color than to use white primer.
>
>Secondly, the primer was applied way too thick. These types of primer
>are formulated to go on in one thin coat, sometimes almost so you can
>see through it. That is what gives the foundation of the paintjob its
>strength. Heavy primer coats are very weak and contribute to "thick
>looking" results by the time the painting is done. The rust inhibiting
>properties are fully intact, whereas if the paint comes off of it the
>primer won't prevent rust without paint on it.
>
>Third, as we discussed before, the paint layers were also too thick to
>the point that where the clamps were, one could have poured plaster in
>it and made a perfect casting of the clamp since the "walls" created by
>the paint smooshing out were so high. All of these technical aspects are
>important to attend to since a beautiful paint job is of no value if it
>doesn't hold up past the point when one starts hanging parts on the
>frame.
>
>So keep the primer thin and continue to the end that way if you want a
>durable finish. Thick primer may work on a classic auto with a
>hand-rubbed lacquer finish; but it's a recipe for failier on a bicycle.
>Hope this information will be of some use to you guys who like to work
>on your own stuff.
>
>Brian Baylis
>La Mesa, CA
>Damn, there was a bicycle under all that stuff!