Re: [CR]A few more tips on painting


Example: Production Builders

Date: Fri, 18 Jan 2002 09:00:01 -0800
From: Brian Baylis <rocklube@adnc.com>
To: classicrendezvous@bikelist.org
Subject: Re: [CR]A few more tips on painting
References: <3C4780E5.1AC0@adnc.com> <00a301c1a036$5375ed00$80de1b41@cinci.rr.com>


Steve,

I wish what you said was true, but alas, I should have said a "professional bicycle painter". Fact is there are some pro bike painters who don't have the "touch".

Brian Baylis La Mesa, CA
>
> Hi Brian,
>
> The "professional painter" who repainted this bike was most likely a
> auto-body or car repainter. They use spray guns that are meant to cover
> large surface areas quickly - but this is not good for bike frames! Wrong
> equipment used = start of a bad paint job...
>
> I had this same experience with a guy who could paint cars great, until he
> screwed up my Columbus tubing frame by caking on the primer and enamel
> paint. The bottom line is that car repainting is not the same as detailed
> bike frame painting...
>
> Regards, Steve Neago
> "Finding better paths in Cincinnati, OH"
> ----- Original Message -----
> From: "Brian Baylis" <rocklube@adnc.com>
> To: <classicrendezvous@bikelist.org>
> Sent: Thursday, January 17, 2002 8:56 PM
> Subject: [CR]A few more tips on painting
>
> > Listmembers,
> >
> > Since the topic of painting bikes came up a few days ago I had the
> > occassion 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!