Steve,
You are correct regarding various paints and methods of application. Urethanes applied properly are best for bike frames for many reasons; we'll just leave it at that.
You're asking for the world when you want to know the details of what equipment I use and other intimate details of paint application I have honed over the past 30 years: but I'm going to give it to you. It was in fact 1972 when I painted my first bike using a cheap Badger air brush. Urathanes can be easily reduced to proper viscosity for spraying through an air brush. But there is a much better paint applicator than that. Go to your local hardware store and buy a mop. Just kidding!
The spray gun of choice up until the advent of HVLP stuff (which I do not use) was the Binks Model 26. It is just like a standard siphon type spray gun except it got shrunk in the wash. It is not a top trigger touch-up gun like a DeVilbuss (although some guys have used those as well) but just a downsized regular gun. They are fitted with an 8oz. cup and that is more than enough paint for most anything. I usually put in around 4 to 6oz of reduced material to spray a color on a frame and fork. The Mod. 26 is out of production but I suppose if you look around you could find one. Ron Smith, the original Masi painter probably determined which gun would work best for Masi and the standard for bike painting was set as far as any spin-off from Masi goes. We all use(ed) them at one time or another. Many of us still do.
OK, that is one piece of important information. From here on I am telling you things that I have kept close to the vest for 25 years. I hope you appreciate what I'm about to do.
First, abandon any conventional settings for pressure at the spray nozzel. I think normal pressures run maybe 35 or 40 psi (I don't even know). Like you mentioned, depending on the paint and even the color and what type of coat is required the pressure varies, but it can be as high as 90 psi for some situations. There is a delicate balance between material and reduction, spray pressure, and the thickness of the coat you apply. This balance is something I can't explain in detail because there are hundreds of variations and the decisions are based on 30 years of painting experience. I have alerted you to what to try and think about and learn about as you work; but that's the best I can do for you here. In general (relatively) high nozzle pressure, more reduction than specified, and move fast. Sounds like a recipe for disaster to a car painter (which it would be) but for painting bikes, it works for me.
If you can get these principals to work for you, then you are on your way. The rest comes from experience and working with your material.
Another key to successful painting is what we call the spray pattern. I was taught the pattern that Ron Smith came up with at Masi. I have not altered it one bit. I have been doing it for 29 years and it allows me to essentially paint with my eyes closed. You always know where you are and it covers every spot in the most effecient pattern I've ever seen. That is really important especially during final clear coats. There is no way to explain how it goes. People who have seen me paint tell me I look like a robotic painting machine. The robot has to think though, since frame size and configuration, and especially braze-ons and bridges vary widely; which means you have to work those into the standard pattern each time.
That should be enough information to get you started. If you have any other questions I will answer them to you personally. Needless to say I can't be answering all questions from all commers about how to paint bikes.
For those on the list who have sent mail to Sam, go easy! I think some may feel Sam is out of line in is questioning. He has an unusual way of stating his questions to me, but I undersatand his curiousity and do not take any personal offence to his questions nor the way he presents them. I don't know him that well, but certainly well enough to know that he means no harm and has a thurst for more knowledge on these subjects.
Time to get catfood. I have to go dangerously close to the new Krispy Kreme donut shop in El Cajon (which caused a traffic jam the day it opened a month ago) that I haven't been to yet. I am going to begin acclamation to North Carolina as of today by inserting Krispy Kreme donuts into my piehole. Beats a sock anyday. Do cats like donuts too?
Brian Baylis
La Mesa, CA
>
> Hello,
>
> For the sake of discussion, the number of "coats" of paint depends in large
> part on the type of paint you are trying to apply... enamel, laquer, or
> polyurethane- which affects your choice of spraying equipment to apply them.
> The style, type, and coats required to apply these paints differ greatly now
> compared to when original bike frames were produced. I view bicycle frame
> painting ***not*** as a "black art" but as a developed skill that requires
> patience, practice, and accuracy to successfully complete a quality job
> using a variety of painting techniques. The paint and equipment you choose
> to use directly affect the quality of the resulting paint job.
>
> Brian, please correct me if I am wrong, but it seems that urethane paints
> may be a better choice for frames (ie Imron or House of Colors), but tend
> to be more expensive, difficult to mix with toxic activators, levelers, etc,
> and have one time use after mixing, but provide a more durable finish and a
> thinner coat while reducing the cure time. Clear top coats are almost a
> requirement to obtain a "wet look". However, they use a "thicker" paint
> normally meant for higher pressure spray guns.
>
> Supposedly, enamels and lacquer require base coats, more layered coats, and
> cure time that result in paint jobs that are decidedly not as durable as
> urethane paints. I have heard that clear coats may not be required for these
> paints because the clear coat is incorporated within the enamel or laquer
> paint? I am not sure if current lacquer paints tend to yellow or dull with
> age like vintage Raleigh bikes that seem to "yellow" dry-transfer decals
> over time. Recent changes in paint chemistry have made enamel and laquers
> about equal in application and durability, but not as durable as urethane.
>
> Brian, what manufacturer/models of paints and spray equipment do you use to
> obtain those marvelous finishes and "wet looks" we are interested in? I am
> currently trying to find out whether I can "thin out" urethane paints to
> make them viscous enough to run through a number of Paasche airbrushes that
> I own without clogging the airbrush. Do you have any suggestions? I
> believe that airbrushes may be a better choice of equipment that
> conventional car spray guns - less paint overspray with more control. For
> those interested, I am using airbrush painting techniques from Airbrush
> Action magazine instructional videos ( http://www.airbrushaction.com ). I am
> trying to apply urethane paints using 45 psi Paasche AB, H, and VL
> airbrushes.
>
> Thanks, Steve Neago
> "Potential painter contemplating his work in Cincinnati, OH"
>
> ----- Original Message -----
> From: <Wornoutguy@aol.com>
> To: <classicrendezvous@bikelist.org>
> Sent: Saturday, January 12, 2002 12:20 AM
> Subject: [CR]Coats of paint
>
> > Brian 15 coats? paint become brittle with more than 3 mills on there.
> I
> > have used PPG, DuPont, PCL, and others -- base coat, thin clear coat, dry
> > then color sand, add decals and custom stripes, two top coats possible
> three
> > of clear. You do paint far better than I do so I am not trying to
> debate
> > this. I have put intricate flames on old cars with less steps. I wish I
> had
> > the time and you felt like walking me through your work area sometime I
> might
> > learn something. Sam DiBartolomeo in Southern CA