Cycling Adventurer: How To... Paint a bike frame

The Cycling Adventurer
How To...	Paint a Bike Frame — Step 8

F (for Finish) Day has arrived

Take a deep breath... Finish Day has arrived. From now on, your patience and the care you've taken with the base work will be tested. And it will take an extraordinarily short amount of time to finish the job compared with the base work. Hopefully, the outcome will be brilliant.

You've also practised on the primer coats with your sweep-and-spray techniques. But for the finish coats, you will build up with 8 or even 10 thin layers to get the depth of colour you need. Overspray might start to become an issue.

Just take things easy... you'll get excited as the colour builds, but rushing it will lead to paint runs. You will get very good results quite quickly with spray paints that dry quickly. You don't have to wait long for the next coat, and suddenly, you will have a high gloss start to appear.

If you are using a slow-drying paint, you'll probably be frustrated that it takes about three minutes to put a coat of two of paint on the frame... then wait a day or more for it to dry sufficiently for another coat. Perfection does take time.

This also is a time when you will find out very quickly whether the paints you used have been compatible. The tricyle project came to a screaming and frustrating halt when I got to the mudguard for the front wheel and had to solve a problem with crinkling of the primer coat when I applied the silver finish coat.

The combination of primer and finish coat were the same for the other components meant to be silver — the handlebars and the ancillary bits for the mudguard — and none of those presented the same challenges.

In the end, I removed all primer and finish coats on the mudguard, resanded the chrome finish, and went with several layers of just the finish coat over the top.

You don't necessarily have to wet-and-dry back between each of the very light coats. I didn't do any sanding between coats on the trike mainframe. But I did stop immediately I obtained a deep, lustrous coat. To spray any more might have led to more overspray than needed, and a dulling of the shine.

If the surface does go dull, you'll have to wait for the paint to dry and then sand it back lightly with the fine paper. If you become impatient and start with the wet-and-dry paper too soon, the paint may (or rather, will) roll off under the sandpaper instead smoothing it back; then you've got problems.

The wait between coats will also allow your index finger to rest — it will get a good workout squeezing the nozzle!

If you have lugs, pay special attention around the lug ends, but go lightly to maintain the definition of the edges and corners. In these areas, ensure the can and nozzle are at a right-angles to the main tube, follow the contour of the curve of the tube.

Keep fingers away from the frame, until it's dry. Use a soft cloth to hold it or use latex gloves. You don't want an errant fingerprint to mar the finish. Take extra care negotiating doorways — any knock now will scar the soft paint. Don't spray when the humidity is high, because that will lead to bubbling as the moisture settles on a cold frame.

By the end of a week of work, you should have a good depth of color, there should be a good and even layer of paint over every part of the frame, and if you are using gloss paint, there should be a fine lustre to it.

But you can go further. I've found paint finishes by themselves to be susceptible to scratching and chipping, but less so if you lay on another three or four coats of clear finish.

I found on my Cycosys project that irridescent colour coats, as used on the Cycosys forks, needed to be totally cured cured before application, otherwise they wrinkled and bubbled slightly; this was more evident on a silver finish on the forks than on the main frame.

The outer clear coat is a great protector for the colour underneath and take a bit to wear through. Because it is clear, however, it is difficult to determine where it has been applied. So apply more light coats rather than fewer.

Here is an additional piece of advice to preserve the finish. After you have left the final topcoat to harden for several days, cover parts that you think might be marred during assembly of other bits.

The finished main frame in a dark, lustrous blue. There are about six coats on there, and the lustre is a result, not of polishing, but of the smooth primer surface, and a gradual build-up for the finish coats.

This is the sort of problem that can occur at anytime, despite all care and attention. The top coat crinkled the primer, and everything had to be removed to start all over again... with just the silver topcoat being applied.

This stage represents risk — the assembly of the components when you might knock pieces
together or drop a tool on the paintwork.

This might take the form of masking tape or clear plastic Cling-Wrap from the kitchen, or even some Bubble-Wrap around the toptube and downtube on a diamond frame.

My first test assembly of the mudguard (yes, it seems to be the jinxed part of the tricycle) resulted in a substantial scratch which led to the primer-versus-topcoat crinkling that I mentioned above.

You can also do things like drop a spanner or slip with one on a nut or bolt, and a chip in the paintwork will result. So... a little added protection now will prevent that sinking feeling in your stomach later on!

Stand back and behold

With some good luck and good management, you should have a beautifully painted bike frame in front of you. And you did it all yourself. Now, turn around and walk away, and stay away for another day at least, maybe two or three. Let the paint fully harden before you start reassembling the components.

I let the main frame of the trike harden for three days before I started putting stuff on it. Much of the time was spent working on other bits, such as a the seat and forks.

If you are like me, you will knock the frame or drop a part or tool on the frame some time before you get the project completed. Just put it down to bad luck... and it's likely that no-one except you will ever notice a small mark is there.

After all, you could have just done a quick graffiti job... it all depends on what quality finish you want.

The trike is finished! The one difficulty was trying to source new, suitable pedals, so I cleaned up and painted the old pair that had a side broken off on each. The trike was duly delivered on Saturday 15 December to the owners in Leduc, Canada, ready for a Christmas surprise for their little
grand-daughter. It is a hand-me-down, from the grand-daughter's aunt who first rode it
more than 40 years ago!

Top of Page

Back How-To...