# FAQs for Dual Action Polishing



## Dave KG (Feb 23, 2006)

FAQs for Dual Action Polishing​
*This thread contains a selection of FAQs for Dual Action Polishing. The thread will be constantly updated with new questions and problems. If you have any FAQs that you would like to add to this thread please post them up and I will include them along with an answer *

*Question
What pad and polish should I choose for (XX) type of car?*

_Answer
There is no hard and fast rule for what pad and product to choose for any specific make and model of car. Some manufacturers have a reputation for harder paints (eg the VAG group, and Mercedes) and others softer paints (eg Honda, Vauxhall). However, when ascertaining what products to use on a car, any preconceptions about paint hardness should really be put to bed before beginning. Instead, choose a test section on the car and start out with the least abrasive combination you have: a type of finishing polish on a finishing pad. See what correction this delivers. If its enough, continue with this. If not, step up to a more aggressive combination such as increasing the pad level to polishing... Keep increasing the aggression until you either get the correction you require or until the amount of paint being removed is at its safe limit.

Typical routes to follow with this for popular products:





































http://i235.photobucket.com/albums/ee41/DaveKG/poorboystz8.jpg[/IMG[/I]

[B]Question
How much pressure should I apply to the pad when polishing?[/B]

[I]Answer
The amount of pressure required typically depends on the polish you are using and the car which is being polished... Generically speaking, you are looking to be applying around 10 - 15lbs of pressure over the head of the machine when using abrasive polishes for paintwork correction.

A good idea is to draw a thick black line on your backing plate. You want to ensure that the backing plate is turning at all times, at no less than about 1 revolution per second. Too much pressure will result in the pad ceasing to turn, so if this happens reduce the pressure a little until it begins to turn again.

It is good practice to reduce the amount of pressure you apply around panel edges and over creases. You will find that the pad is more inclined to stop turning over these regions which serves as a good indication to reduce the pressure here. Paint thicknes on edges can sometimes be thinner than over large areas so a reduction in pressure here is good practice.[/I]

[B]Question
How big an area should I work on at any one time when machine polishing?[/B]

[I]Answer
When using abrasive polishes for defect correction, the work area should be no more than 2' square, but ideally I would say to aim for 12 - 18" square. Working areas which are too large at a time will result in lower levels of correction and poor finishing as the polish will be more inclined to dry up before fully worked.

You can increase the level of correction a little by focusing down the work area to a smaller size - this can lengthen the work time per unit area and hence increase the level of correction achieved.

If you find that polishes are drying out too quickly, one solution to solving this is to reduce your work area.[/I]

[B]Question
How fast and in what pattern should I move the machine?[/B]

[I]Answer
It matter not which patterns you use when moving the machine: up and down, side to side, figures of 8. Take your pick! :) So long as you cover the area evenly.

When using correction polishes, the machine should be moved very slowly - at around 1 - 2" per second. The machine has to work the abrasives in the polish to break them down, and to achieve this at its best requires slow movements. If the machine is moved too quickly, the polish abrasives are not broken down and it results in poor correction and micromarring in the finish.[/I]

[B]Question
At what machine speeds should polishes be worked?[/B]

[I]Answer
The answer to this question varies from polish to polish, and from machine to machine. For the popular G220/UDM/PC, most polishes once spread can be worked between machine speeds 5 and 6. The higher speeds will get the best out of the polishes by working the abrasives more thoroughly. Some polishes, for example Meguiars #83, prefer to be worked at the lower end of this speed scale: speed 5 maximum. Too high a speed can dry a polish out, so if this appears to be the case then reduce the working speed.[/I]

[B]Question
How long should I work a polish for?[/B]

[I]Answer
The answer to this question in terms of a time varies widely from polish to polish, but a good rule of thumb is to polish until the residue of the polish goes clear and in the cases of some polishes, until they are dry and start to dust slightly. This can typically take between 3 - 5 minutes per section, so as you can realise, machine polishing is not a fast job! Take plenty of time and effort to ensure you fully work polishes as this will deliver the best in terms of correction and also the sharpest finishes allowing for optimum clarity and gloss.

The pictures below show a typical polish being worked through the abrasive stages from spreading (cloudy residue) to fully worked (clear residue):

[IMG]http://i235.photobucket.com/albums/ee41/DaveKG/P1010003-7.jpg

















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## -ROM- (Feb 23, 2007)

that's great dave, almost like a bullet point check list to refer back to after reading your full DA guide!


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