Cebola_1
08-06-2006, 21:42
Removing paint defects using
a Porter Cable 7424 polisher.
This five year old Honda belongs to our neighbor, Sherry. It had accumulated a number of door dings and scratches over the years and Sherry's husband had tried to remove the scratches with an abrasive rubbing compound. The result was a series of dull, compounding spots along the passenger side of the car.
Polishing would have restored gloss to the hazy patches caused by the rubbing compound but might not have removed the remaining scratches on the door.
The best solution, to remove the remaining defects and restore surface gloss, would be to compound, polish and finish the blemished areas.
This is the same three step procedure used by automakers, body shops and professional detailers.
In this article, we used a Porter Cable, dual-action polisher to compound and polish the rear passenger door. In another article, we did the same procedure on the front passenger door with a circular polisher. For that article, see "Removing paint defects using a circular polisher."
Compound - Polish - Finish
Compounding involves abrading away the area surrounding the scratch or blemish until the defect is no longer visible. This is best accomplished with a circular polisher (DeWalt 849) but dual-action polishers like the Porter Cable 7424 will remove minor defects and visually reduce deeper swirls, scratches and blemishes. Compounding may leave the surface dull. This is normal. This dullness, or compounding haze, is removed in the next step which is polishing.
Polishing removes compounding haze and restores surface gloss. It creates a mirror-like, highly reflective finish ready for waxing. Polishing is best accomplished using a white foam polishing pad and a finishing polish.
Finishing protects the surface with your favorite wax or sealant. Finishing can be accomplished by hand or with a dual action polisher (Porter Cable). Applying a wax or paint sealant by machine is typically done using a black foam finishing pad.
About dual-action polishers:
Dual action polishers trade safety for ultimate paint cutting ability. Since the pads oscillate (jiggle) rather than rotate, dual action machines may not be able to abrade away enough of the top clear coat to completely remove deep swirls, defects and scratches. That said, dual-action polishers will always produce better results than could be achieved by hand.
On the plus side, the random, oscillating motion of dual action polishers makes these machines very safe for novice users. It is virtually impossible to damage the paint or clear coat with a dual action polisher.
Repairing the blemishes on this vehicle falls in between spot repair and whole-panel repair. The general rule of thumb is to use smaller, 3 inch, wool discs and pads for removing defects in a specific area. Full size wool discs and foam pads are used if the entire panel or the entire vehicle needs to be compounded and polished. The defects on this vehicle covered half of the door's surface. While I could have used full-size pads, I decided to use the smaller pads in our Spot/Scratch Repair Kit. These smaller pads give me more control over the area being compounded and leaves surrounding areas unaffected.
Product requirements:
Dual-action polisher (Porter Cable 7424)
Spot/Scratch Repair Kit
A compound such as Menzerna Intensive Polish, Meguiar's Medallion Premium Paint Cleaner or 3M Fine Cut Compound.
A polish such as Menzerna Final Polish, Meguiar's No. 9 Swirl Remover or 3M Perfect-It Swirl Mark Remover
Your favorite wax or paint sealant.
Procedure:
Step 1 - Compounding
Place the wool polishing disc on the backing plate and attach to your machine polisher using the adapter (if needed).
Work on a small area, 12 to 18 inches square, out of direct sunlight.
Apply compound directly to the surface.
Mist the wool disc very lightly with water.
With the machine off, spread the compound (i.e. Menzerna Intensive Polish, Meguiar's Medallion Premium Paint Cleaner) over the surface using the wool disc. This coats the wool disc with compound and reduces compounding paint temperatures.
Press the wool disc against the paint and turn the machine on. Set the speed dial on the polisher between 3-1/2 and 4.
Work the pad over the surface in a figure 8 pattern. Go over the area in a left-to-right figure 8 pattern and then an up-and-down figure 8 pattern.
Go over the area several times or until the compound starts to dry.
Inspect the results. Spray the surface with a 50/50 solution of Isopropyl Alcohol and water to remove compounding residues and wipe the area dry with a clean Microfiber towel. (I mark one of the water bottles "Water/Alcohol" with a Magic Marker to keep them separate) Run your fingertips over the surface. Is it smooth?
Has the scratch or paint defect been removed? If not, repeat the compounding and inspection procedure until the scratch is removed or until no further improvement can be observed. When the surface is as defect-free as you can make it, proceed to Step 2, Polishing.
Compounding may leave the surface dull depending on the abrasiveness of the compound used. This is normal. This dullness is removed in the next step which is polishing.
Polishing is done after compounding to remove compounding haze (surface dullness). Polishing restores surface gloss and prepares the surface for waxing.
Step 2 - Polishing
The procedure for polishing is exactly the same as for compounding with two exceptions.
Use the White Foam Polishing Pad for this step with a finishing polish (i.e. Menzerna Final Polish, Meguiar's No. 9 Swirl Remover).
Mist the white foam polishing pad with water, spread polish over the area and polish in a figure-8 pattern.
To test for results, wipe off polishing residues with a clean Microfiber cloth and inspect the surface. (Do not spray the surface with the alcohol and water solution. This would remove fillers and gloss agents that you want to stay on the surface.)
If the surface is still dull, continue polishing. When the haze is removed and surface gloss looks good, proceed to finishing.
Step 3 - Finishing
After polishing, finish with your favorite wax or paint sealant/ protectant. You can do this by hand or use the appropriate pad or bonnet for your machine polisher (not supplied in Spot/Scratch Repair kit).
When you're finished, wash all pads in a bucket with soapy water, rinse thoroughly with a garden hose and allow to air dry. Do not machine wash or dry pads.
What kind of results can I expect?
In all cases, this system will produce better results than could be accomplished by hand. Using a circular polisher will completely remove swirls, scratches, paint defects and acid rain, water spots.
Using a dual action polisher will remove minor swirls and visually reduce deeper swirls, scratches and paint defects. It may not be possible to completely remove deep swirls, scratches and acid rain water spots using a dual action polisher .
Note: Scratches deep enough to be felt with your fingernail can be made to look better but probably can not be entirely removed. You should not attempt to remove scratches that go all the way through the paint or clear coat. These scratches require re-painting and should be repaired by a body shop technician.
a Porter Cable 7424 polisher.
This five year old Honda belongs to our neighbor, Sherry. It had accumulated a number of door dings and scratches over the years and Sherry's husband had tried to remove the scratches with an abrasive rubbing compound. The result was a series of dull, compounding spots along the passenger side of the car.
Polishing would have restored gloss to the hazy patches caused by the rubbing compound but might not have removed the remaining scratches on the door.
The best solution, to remove the remaining defects and restore surface gloss, would be to compound, polish and finish the blemished areas.
This is the same three step procedure used by automakers, body shops and professional detailers.
In this article, we used a Porter Cable, dual-action polisher to compound and polish the rear passenger door. In another article, we did the same procedure on the front passenger door with a circular polisher. For that article, see "Removing paint defects using a circular polisher."
Compound - Polish - Finish
Compounding involves abrading away the area surrounding the scratch or blemish until the defect is no longer visible. This is best accomplished with a circular polisher (DeWalt 849) but dual-action polishers like the Porter Cable 7424 will remove minor defects and visually reduce deeper swirls, scratches and blemishes. Compounding may leave the surface dull. This is normal. This dullness, or compounding haze, is removed in the next step which is polishing.
Polishing removes compounding haze and restores surface gloss. It creates a mirror-like, highly reflective finish ready for waxing. Polishing is best accomplished using a white foam polishing pad and a finishing polish.
Finishing protects the surface with your favorite wax or sealant. Finishing can be accomplished by hand or with a dual action polisher (Porter Cable). Applying a wax or paint sealant by machine is typically done using a black foam finishing pad.
About dual-action polishers:
Dual action polishers trade safety for ultimate paint cutting ability. Since the pads oscillate (jiggle) rather than rotate, dual action machines may not be able to abrade away enough of the top clear coat to completely remove deep swirls, defects and scratches. That said, dual-action polishers will always produce better results than could be achieved by hand.
On the plus side, the random, oscillating motion of dual action polishers makes these machines very safe for novice users. It is virtually impossible to damage the paint or clear coat with a dual action polisher.
Repairing the blemishes on this vehicle falls in between spot repair and whole-panel repair. The general rule of thumb is to use smaller, 3 inch, wool discs and pads for removing defects in a specific area. Full size wool discs and foam pads are used if the entire panel or the entire vehicle needs to be compounded and polished. The defects on this vehicle covered half of the door's surface. While I could have used full-size pads, I decided to use the smaller pads in our Spot/Scratch Repair Kit. These smaller pads give me more control over the area being compounded and leaves surrounding areas unaffected.
Product requirements:
Dual-action polisher (Porter Cable 7424)
Spot/Scratch Repair Kit
A compound such as Menzerna Intensive Polish, Meguiar's Medallion Premium Paint Cleaner or 3M Fine Cut Compound.
A polish such as Menzerna Final Polish, Meguiar's No. 9 Swirl Remover or 3M Perfect-It Swirl Mark Remover
Your favorite wax or paint sealant.
Procedure:
Step 1 - Compounding
Place the wool polishing disc on the backing plate and attach to your machine polisher using the adapter (if needed).
Work on a small area, 12 to 18 inches square, out of direct sunlight.
Apply compound directly to the surface.
Mist the wool disc very lightly with water.
With the machine off, spread the compound (i.e. Menzerna Intensive Polish, Meguiar's Medallion Premium Paint Cleaner) over the surface using the wool disc. This coats the wool disc with compound and reduces compounding paint temperatures.
Press the wool disc against the paint and turn the machine on. Set the speed dial on the polisher between 3-1/2 and 4.
Work the pad over the surface in a figure 8 pattern. Go over the area in a left-to-right figure 8 pattern and then an up-and-down figure 8 pattern.
Go over the area several times or until the compound starts to dry.
Inspect the results. Spray the surface with a 50/50 solution of Isopropyl Alcohol and water to remove compounding residues and wipe the area dry with a clean Microfiber towel. (I mark one of the water bottles "Water/Alcohol" with a Magic Marker to keep them separate) Run your fingertips over the surface. Is it smooth?
Has the scratch or paint defect been removed? If not, repeat the compounding and inspection procedure until the scratch is removed or until no further improvement can be observed. When the surface is as defect-free as you can make it, proceed to Step 2, Polishing.
Compounding may leave the surface dull depending on the abrasiveness of the compound used. This is normal. This dullness is removed in the next step which is polishing.
Polishing is done after compounding to remove compounding haze (surface dullness). Polishing restores surface gloss and prepares the surface for waxing.
Step 2 - Polishing
The procedure for polishing is exactly the same as for compounding with two exceptions.
Use the White Foam Polishing Pad for this step with a finishing polish (i.e. Menzerna Final Polish, Meguiar's No. 9 Swirl Remover).
Mist the white foam polishing pad with water, spread polish over the area and polish in a figure-8 pattern.
To test for results, wipe off polishing residues with a clean Microfiber cloth and inspect the surface. (Do not spray the surface with the alcohol and water solution. This would remove fillers and gloss agents that you want to stay on the surface.)
If the surface is still dull, continue polishing. When the haze is removed and surface gloss looks good, proceed to finishing.
Step 3 - Finishing
After polishing, finish with your favorite wax or paint sealant/ protectant. You can do this by hand or use the appropriate pad or bonnet for your machine polisher (not supplied in Spot/Scratch Repair kit).
When you're finished, wash all pads in a bucket with soapy water, rinse thoroughly with a garden hose and allow to air dry. Do not machine wash or dry pads.
What kind of results can I expect?
In all cases, this system will produce better results than could be accomplished by hand. Using a circular polisher will completely remove swirls, scratches, paint defects and acid rain, water spots.
Using a dual action polisher will remove minor swirls and visually reduce deeper swirls, scratches and paint defects. It may not be possible to completely remove deep swirls, scratches and acid rain water spots using a dual action polisher .
Note: Scratches deep enough to be felt with your fingernail can be made to look better but probably can not be entirely removed. You should not attempt to remove scratches that go all the way through the paint or clear coat. These scratches require re-painting and should be repaired by a body shop technician.