Wednesday, September 29, 2010

Polishing bike parts for extra bling

~ By Charles Mitchard (Atomic Zombie builders forum), Australia

When building re-cycled bicycles of any description we often go to great lengths to ensure the final product is pleasing to the eye. Sometimes it’s the little things that make a huge difference so we buy new ones to create that finished shiny appearance.

I haven't done the costings but it is possible to clean and polish even heavily corroded components for very little outlay. For only one bike it may not be that cost effective if you have to purchase all the equipment but if you only have one item such as an electric drill then it becomes much more affordable and many dollars can be saved.

Tools required and safety hazards

  •  A bench grinder, the more powerful the better. There are many ultra cheap Chinese imports available but some of them are very wimpy. It is possible to stop the less powerful machines with the pressure used in polishing which is why a more powerful machine is better so get the most powerful you can afford.
  • Two canvas, linen or denim buffing wheels.
  • Make sure they are stitched around from the centre out to keep the layers from separating. I prefer a rough sisal buff for the Tripoli compound as its more agressive
  • One tapered end spindle for the shaft of the grinder, they come in left and right hand threads. In practice one is sufficient, as you will have to wash the parts between polishing compounds so no time is saved by using a buff at each end.
  • Tripoli cutting compound. This is used to remove sanding marks.
  • Red Rouge polishing compound. I leave this step out as I've never found it necessary but it can improve the final finish.
  • White Rouge polishing compound. This is the final compound that gives the ultra diamond bright shine. All three of these compounds can be found in lapidary or jewelry suppliers (check the yellow pages) if they are unavailable in your local hardware store. Australians will find them in Bunnings.
  • Assorted sheets of emery cloth, from medium to ultra fine, ie. 200 to 1600 grit.
  • You may have to change to wet and dry sanding paper for the really fine stuff. Just use what is available.
  • Although not entirely necessary a wire wheel brush is a fast way of removing corrosion or rust first.
  • A face mask and goggles are essential safety equipment. A lot of dust and black **** will be produced and you do not want it in your eyes or lungs.
We will start with this horrible looking handlebar stem.

 


If the original parts were anodised then this has to come off as well. Caustic soda solution (DANGER, BURNS FLESH) will do the job but Easyoff (or similar) oven cleaner is a tad safer. Both methods are messy.

Use the wire wheel on a drill or the bench grinder (I use a drill press) to remove all the paint, corrosion and other blemishes. Be careful on aluminium, as the wires will leave deep grooves which you can see in the picture if kept in one position for too long. If no wire wheel is available then use coarse emery cloth which in all honesty will do a better job but take longer.

The next bit is heaps of elbow grease. Go down through the grades of emery cloth from the coarsest to finest sanding till all the blemishes from the previous grade have been removed. Deep gouges are not possible to remove but most other damage is.




Heavy damage can sometimes be removed with gentle filing but be careful not to make the problem worse.

When moving down through the grades try to go in different directions, ie first grade sanded north/south, second grade sanded east/west.This helps to prevent deepening any scratches present.
This is the stem after finished sanding. It could have done with a bit more work.



Once you are satisfied that all the scratches have been sanded out and you have finished by using the very finest paper it is time to start with the polishing compounds.



Mark the buffs one with an R for rouge and the other with a T for Tripoli and don’t mix them up. Store them in a zip-lock bag when not in use to prevent contamination.

This photo is showing two cotton buffs but I now use a sisal for the Tripoli.




Stay tuned for Part 2 coming soon...