My MK1 Golf, Dilbert

Documenting my Mk1 Golf show car build

Saturday, August 29, 2009

Polishing steps

Posted by marc keeley |

Here's a quick run down of the polishing steps we are using on the aluminium components, polishing steel is similar but will use different mops and compounds:

  1. Filing, Any casting marks and unwanted features such as lettering are carefully filed away.
  2. Preparing, Sanded with 320 grit wet & dry to remove all surface irregularities and blemishes. We use a B&D mouse sander and sanding block depending on the area.
  3. Burnishing, Bench grinder using grey compound with a sisal polishing mop.
  4. Prepolishing, Bench grinder using green compound with a white close stitched polishing mop.
  5. Polishing, Bench grinder using blue Compound with a loose G quality mop.
  6. Finishing, Bench grinder using Menzerna P175 for super finishing with a loose WDR quality mop.
  7. Post Finishing, hand polish with ultra-fine metal polish and ultra-soft micro fibre cloths.

As we didn't have P175 we made our own compound using a mixture of regular bathroom talc and 3-in-1 oil. Talc is one of the finest abrasives you can get (finest as in courseness), the oil is used as a carrier. A G quality mop could be used if you haven't a WDR. For the final hand polishing we use Zeppelin Prep and then Zeppelin Mirror Finish from English Custom Polish.

Unfortunately the mirror finish won't last forever when exposed to air which is why some turn to chroming. However a mirror polished surface is brighter than chrome, which has a slight blue tint to it. Initially we considered a standard clear coat but they tend to be too heavy and take the edge off of the shine. Eventually we came across a US product by Everbrite called Protect-a-Clear which doesn't affect the finish in any way being crystal clear. Neither will it yellow or crack over time, which is obviously important, and should last for at least 5 years.

Saturday, August 29, 2009

Sanding & polishing safety

Posted by marc keeley |

Here's a run down of some safety guidelines you should bear in mind when sanding and buffering. All pretty much common sense.

Aluminum dust is poisonous so wear gloves, gogles and a respirator when sanding and buffing. A painters mask isn't sufficient, use the gas mask type with the twin filters. If you don't like wearing gloves whilst sanding then use a barrier cream.

Don't wear loose clothing or anything else that could be entangled in the bench grinder. Also make sure things like power cables are kept away from the grinder, preferably tied down.

Should any polishes or particles get into the eye, flush eyes well with water. DO NOT RUB!!! Contact your nearest hospital if irritation persists.

Treat the bench grinder with respect. Always wear riggers gloves or similar, goggles, a respirator, ear defenders and preferably a leather apron. A grinder will spit out a piece that slips out of your grasp at up to 80MPH and can cause serious injury.

Only use the part of the buffing wheel that is rotating away from the workpiece.

When buffing parts with sharp edges or hooks they should be offered to the wheel with the edge flowing away from the buffer so the part doesn't catch.

If you are using a hand drill to buff then secure either the drill or the component.

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