sandblasting
 

I want to give my ride a new look and figured off the bat it would be a piece of cake. Wondering if I can treat it like an auto job, grinder or sander for paint removal, rust resistant primer, and some classy enamel for the finish. What other considerations should I factor in here? Thanks!

What's it made out of?

A bike is not the same as a car. Good bike frames are usually very thin metal. Even good steel frames use very thing gauge tubing walls and aluminum frames are even more fragile. Sand blasting is likely to do serious or fatal damage to either material. Carbon is definitely an absolute no-no for blasting media of any type.

Ask a local frame builder how he prepare his frames for painting and follow his advice.

Soda blasting is a more gentle media to use but I don't know if it'll work in a regular sandblaster or not. Plastic beads might be an option instead of sand.

Media/abrasive blasting is likely unnecessary. The factory finish came off my bike in less than 15 minutes using water-based stripper and some Scotch-Brite pads.

You can use a media blaster on steel frames but you need to be careful. Keep the pressure down and don't get up close and personal. I've got a spot blaster that I use with regular silica but only after chemical and hand stripping. I use it to get the last bits of paint and rust out of the corners as well as to give a fine, even satin finish to the metal which is the perfect tooth for taking primer.

Vapor blasting is superior for this type of work.

Modern automotive body panels are 22 gauge (0.8 mm) mild steel. Double butted steel tubsets are usually between 0.6 and 0.4 in the thin areas, but use a much higher grade (stronger) steel. A little caution is advised, but it's not like the walls will collapse if you look at them funny. With less abrasive media and/or lower pressures, media blasting is a completely safe method of paint removal for steel bicycle frames - and probably much less risky than a grinder or coarse power sander. Powder coating almost always starts with media blasting the frame.

But my advice for people looking to re-paint a bike frame is always: "don't". It's a huge time sink and it's really hard to get a good looking result that lasts. The two most effective techniques are catalyzed urethane automotive paint (expensive, needs high end equipment, requires lots of prep) and alkyd enamel brush painting (inexpensive, minimal equipment, requires lots of time for prep and application). Both use standard automotive prep techniques (etching primer followed by repeated application of conventional primer followed by wetsanding), but the tight angles and small diameter tubes make good spray application a real challenge. It can be done, but you'll be amazed how much time it takes to do it right compared to a (relatively) flat automotive body panel.

The best solution is powdercoating. It costs about the same as a urethane paint job but needs virtually no prep work and is significantly more durable than most other finishes.

Howdy All;

We used to use glass beads for "Blasting" aircraft skin (0.032"), when I was doing aircraft corrosion control.
But that was only as a last resort. We always used the mildest method possible. Generally an organic
stripper that was "killed" with water. Brass brushes for getting the bits out of wielding or other awkard
cracks and crevasses.

hank

for a steel bike: Chemical remover. for a good paint job you need to get all the paint off no grinders, etc

Rattlecan jobs can come out very nicely, but are in no way as durable as automotive paint

steps at a very high level for a steel frame

remove all paint

acid etch primer

sandable primer

sand smooth

multiple thin coats of color, pay careful attention to recoat time...... IMHO easier to plan for a day and recoat as soon as possible

multiple coats of clear

Yellow Pages, powder coating, call, visit, write check for $100, take shiny bike home.

I've been down the DIY road. It can be done, it can look great. But unless sanding is part of the hobby for you it is wasteful of time that could be better spent.

...+1. Life is short, and the PC guys blast prep stuff all the time. If there's a downside, it's that they sometimes powdercoat stuff you don't wan them to, like threads and crown race seats.

I was taught that most read a bike by it's cover, the paint job. So if you want your bike to look good and be thought of as a good bike then get a good paint job.

So what's a good paint job? Maybe one with a luster and depth of tone. Decals are smooth and seem to float in the finish. Joinery is not muddled and the crisp raw features remain so. Of course better corrosion protection and surface chip resistance are important. Better powder jobs get a few of these aspects well but only great powder jobs get most well. Low cost powder jobs don't get even the chip resistance good. Andy.