Thursday, May 31, 2012

Painting Bicycle Frames

We have some bright, new colors appearing on the bicycles at Granja Peniel these days...

After only months of preparation....

Newly painted bicycle frames
Things are finally coming together....

It all started with a donation last November from a short-term Baptist work team working near Bogota.  They wanted to bless the boys in our program, so through Felix Pinzon they made a donation for the parts and materials to fix up their bicycles.  Of course, the boys would provide the labor and learn more about their bikes in the process.

We picked out the six frames in the worst shape - or in one case, a PINK bicycle that was somewhat an embarrassment for the assigned boy to ride.

Step one was to completely disassemble each bicycle, stripping it down to the bare frame.

Juan Felipe Garcia with the components removed from his bicycle.

Joel Garcia, looking forward to having a bicycle some other color than PINK!

Johan Egson Fonseca dismantling his bicycle in preparation for re-painting

The next step was to strip off the existing paint with paint remover and by sand blasting.

Johan applying paint remover to his bike frame 

Yordan Garcia sandblasting the frame of his bicycle
After some trial and error, we found that 40-60 grit silica sand works the best in our sandblasting pistol, with 125 psi air.  The ceramic nozzle in the sandblasting pistol was worn out, so fortunately Grant was able to buy some replacements cheaply while visiting the US in January...

Johan Egson Fonseca sandblasting

Bike frame stripped down to bare metal, ready for paint

We decided to build a special rack to hold the bicycle frames for painting using a spare piece of rectangular tubing and some wood we had on hand.  We still need to turn the frame end for end while painting, but the rack gives easy access for the spray gun.

The painting rack holds up to six frames, forks, or handlebars.

We wanted to use durable paint so that our efforts hopefully won't have to be repeated any time soon.  We ended up buying polyurathane automobile paint, which comes which is a two-part paint (dries fast!) with its special solvent.

The grey primer was fast and easy to apply, we used two coats.

Frames drying after primer was applied.

Since I bought only dark green and basic yellow, we had to mix the final colors.  We made some trial mixes to see how they looked, as shown in the photo below.  On the top row, the full green is on the left, the yellow on the right, and various combinations in between.  The rows going down the pane show increasing content of white paint.  We ultimately a bright green (top center) and a taxi yellow (bottom right).

Glass pane with various color mixtures. 

Alberto sanding the primer before applying the finish coat.

I applied all the finish paint, because the small, tubular shape of the frames makes them difficult targets to apply enough paint to shine, without causing the paint to run.

So as to avoid problems with overs pray, we painted different colors separately.

Here are all six frames with the finish paint.

Now it's time to put the bicycles back together, but that has to wait a bit more, until Grant returns from the US...stay tuned.

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