Porter Cable 7424 : Starters Guide

[Dave KG]

In this thread I aim to present some general guidance tips for people who have recently bought a Porter Cable 7424 and describe the machine a little!


The Porter Cable 7424
Browsing this forum, you cannot help but notice that the PC7424 is extremely popular. It is a dual-action polisher that is safe to use and can remove paint defects to help you achieve that sought after swirl free finish. Its a popular tool owing to hte dual-action nature which makes it very safe to use, much safer than a rotary in the hands of a novice. Yet swirl removal is still possible with it, so you come close to getting the best of both worlds!

The tool in all its glory:




What Is A "Dual-Action" Polisher
Dual-action describes the way that the pad moves with the polisher, and the dual-action nature is what makes the Porter Cable 7424 (and 7335) a speical tool. Shown in the diagram is the difference between a conventional rotary polisher and a dual-action polisher:



The conventional rotary pad spins on a single axis, forming a circular orbit of constant radius. This nature makes the rotary quite an agressive tool with the ability to cut paint quickly - while this makes it more effective at swirl removal, it also makes paint damage a real possibility in the hands of a novice.

The dual-action pad not only spins, but it oscillates as well developping random orbits, with varying elliptical orbits. This makes the cutting action much less aggressive and much safer for novices to use. The motion very closely mimicks hand polishing, only the 7424 can oscillate up to 6000 times a minute, which is completely impossible by hand!! This fast oscillation generates much more heat than by hand to more effectively break products down and cut into the paint.


So Many Polishes - Which to Choose??
Once you have you're PC, you are confronted with a daunting array of polishes from a wide variety of manufacturers. At the end of the day, all of these products can be summed up into groups that carry out certain tasks:

Compounds
These are the most aggressive cutting polishes and are generally applied by rotary polisher to deal with severe swirl marks and scratches. You can use a compound on a PC but it requires a 4" pad to generate enough heat to effectively break the product down. Examples of compound: Menzerna Power Gloss Compound, Poorboys SSR3. Only choose a compound if your paint has very severe swirl marks and the cutting polish is proving unsuccessful in dealing with them.

Cutting Polishes
These are medium abbrassive polishes that are designed for the removal of medium swirl marks in paint. They can be applied on a 6" pad, or for extra cutting ability, a 4" pad. Only choose a cutting polish if the swirls in your paint are too severe to be removed by a light cutting polish. Examples of cutting polishes are: Menzerna Intensive Polish, Poorboys SSR2.5, Meguiars #83.

Light Cutting Polish / Finishing Polish
These are light abbrassive polishes that are designed for finishing - ie use after a more aggressive polish or compound to remove any marring that may have been left by the more aggressive product and to restore surface gloss. The can be applied on a 6" pad. Examples of light cutting polishes are: Poorboys SSR1, Meguiars #80.

Glazes
These are essentially moisturisers for paint! They add paint oils to replace depleted oil and to wetten the shine and deepen the colour and are a highly recommended part of the detailing process. Examples of glazes are: Menzerna Finishing Touch Glaze, Meguiars #7.

For further information on which polishes to choose for swirl removal, see also this thread: http://www.detailingworld.co.uk/showthread.php?t=4536


What Pads to Choose??
There are four main classes of pads available from manufacturers and these are colour coded so you know which pad is which. Alas, different manufacturers use different colour codes! The texture of the foam effects what the pad does - ie how much it cuts etc. Summarised in the table below is a breif guide to the uses of the classes of pad:



If you are using Lake Country pads, the colour coding is as follows:

Yellow = Cutting; Orange = Light Cutting; White = Polishing; Black = Finishing.

If you are using Sonus DAS pads, the colour coding is as follows:

Orange = Cutting; Green = Light Cutting; Blue = Polishing/Finishing

If you are using Sonus SFX pads, the colour coding is as follows:

Yellow = Cutting; White = Light Cutting; Blue = Polishing/Finishing

If you are using Meguiars pads the colour coding is as follows:

Burgandy = Cutting; Yellow = Light Cutting/Polishing; Beige = Finishing

For further information of which pads to choose for a specific task, have a look at this thread: http://www.detailingworld.co.uk/showthread.php?t=4536

Note that the above table is intended as a starters guidance only, and over time you will find out which pad and product combinations that you like best!


Setting Up The PC7424 For Use
Getting ready to use the Porter Cable... If you turn the Porter Cable upside down, you will see the following:



Make sure that if you are planning to use 4" pads that you have the counter-weight for 5" pads fitted. Some pCs are now being supplied with a 6" counter-weight which will make the machine very hard to control with a 4" pad fitted. 5" counter-weights are available from http://www.polishedbliss.co.uk if required.

First off, choose the correct backing plate for the pad you intend to use - 3.5" backing plate for a 4" pad, 5" or 6" backing plate for a 6" pad:



First off, fit the backing plate to the Porter Cable. Using the flat spanner supplied with the machine, hold the centre nut as shown:



Now, screw the plate into the thread in the middle of this centre nut while holding the nut still with the spanner to prevent it from spinning with the pad, and tighten the backing plate continuing to hold the centre nut with the spanner:



The pads fit to the backing plate using a velcro (sometimes called "hook & loop") system so just stick the pad securely to the backing plate, trying to keep the plate in the centre of the pad area.

Once the pad is fitted, you just need to plug the PC in and you're ready - make sure you use a transformer however!! Plug the transformer into the mains (230V) and plug the Porter Cable into the 110V output of the transformer:



Never plug the PC straight into the mains, this will damage it irreperably!

[Dave KG]

Polishing with the PC7424
The key to successful polishing with the PC is to work on small areas, and take your time. What follows is a generic guide to polishing with the PC, as you work with the machine you will develop the technique that you feel most comfortable with, this is aimed at being a starting guide.

To hold the PC, I like the place my right hand over the head of the PC and have my left hand at the back of the PC:




This allows me to put pressure over the polishing pad while the PC is in use, and pressure is required to get decent swirl removal (but not too much, see later!)

First off, apply the polish to the pad on the PC, in either an X (which stops three quarters of the way out from the centre) or a circle round the edge of the pad, about quarter of the way in from the edge.

Next, with the machine switched off, smear this across a small area of about 2' x 2'. Make sure you can comfortably reach the hole area and that you are not stretching too far - the more comfortably you can reach areas the happier you'll be operating the tool. A small ladder is useful for doing the roof, especially if you're short! After spreading the polish, turn the machine on at about speed 3.

Do a single fast pass with light pressure over the pad to further spread the polish out.

Then turn the machine up to speed 5, and make a single slow pass with pressure applied over the pad. Move the PC at around 2cm per second in either a fore and aft motion or a figure of eight motion, what ever you are most comfortable with providing you achieve even coverage. (I prefer a fore and aft motion).

Next turn the machine up to full speed - speed 6 and make several slow passes with pressure applied over the pad until the polish begins to dust. At this point, switch off the machine and buff the residue away with a microfibre towel. If the residue resists easy buffing, a little spray of Quick Detailer spray on the mf towel should help remove the residue more easily.

How much pressure?? - apply about 10 - 15lbs of pressure. To get an idea of what this feels like, you can get out the bathroom scales and puch down till it reads 10 - 15lbs plus the weight of the PC. Or, I much prefer the following: push down on the PC until you get a noticebale change in pitch from the machine and the pad stops visibly spinning, it is just oscillating. Then reduce the pressure ever so slightly so that the pad begins to spin again, and this amount of pressure is good.


Glazing with the PC7424
The PC can be used for other tasks than polishing. Glazing really benefits from using the PC as the extra speed of the PC over hand application works the oils in glazes nicely into the paint. I find the following process works well for applying glazes:

Apply product to pad (as above for polishing, X or circle) and smear over a small area. Turn machine on at speed 3 and make one fast pass to spread the product more and then one slower pass to begin working the glaze into the paint. Then turn the machine up to speed 5 for two or three more slow passes. All with light pressure over the pad. Then buff off residue with an mf towel.


Applying Liquid Waxes & Sealents by PC7424
The PC can cut down the time taken and effort required in applying liquid waxes and sealents! Again, apply the product to the pad as the glazing or polishing stage above. Turn then machine onto speed 2 or 3 and move the PC slowly across the paintwork to spread the product evenly. Fast speeds are not required for this process. Always observe the manufacturers recommendarions for the time left for the product to cure before buffing off residue.


Applying Paste Waxes by PC7424
Even some paste waxes can be applied by the PC, though, many people prefer to apply these by hand. If you wish to apply by PC, follow the process for liquid waxes and sealents above. Most pastes waxes can be popped out of their containers, just rub the wax round the PC pad to charge the pads up, a but like buttering a piece of toast! Again observe the manufacturers guidelines for the length of time the product should be left to cure.


And there we have it! If you've just bought a PC, I hope you find this guide helpful in getting started. You will develop your own methods with experience (for example the speeds you like, the pad and polish combos you like) which may differ from those here, what ever works for you, go for it! I hope you enjoy the tool that I consider to be one of the best detailing purchases I ever made!

[ayr320cdmsport04]

Well done m8!
Gr8 wee guide 4 us PC wannabees!
I`m def gonna get one for my bmw sapphire black metalic faint swirls/cobweb etc,so could u help with wot pads/accessories/polish etc i need for the best look on a black car? Plus do u all meet up in scotland for demo`s advice etc? if so would b up 4 meeting if off work and volunteer my car 2 ur capable hands if u wanna show ur skills off!
Can`t wait till summer 2 have a go at

Cheers again gr8 guide.

[L200 Steve]

Another superb guide there Dave.

Well done mate, this'll be a very useful link for all the new PC owners out there

[neilos]

Dave, a great guide....

I'm thinking of getting a PC for the summer, but wasn't really sure if it was as suitable just for applying glaze and wax etc as it is for swirl removal.

Now I know for sure, and will be getting a PC for sure...

[geri]

great guide Dave just what i need been thinking about getting a pc for ages and your guide is really helpful to get a better idea of what it's all about.

Nearly bought one last year but got persuaded out of it by a friend who insisted i'd ruin the paint on my car! and that it was no different to a rotary that he had so your guide is a big help to me cheers

[steeleez]

Superb write up mate, I've got snippits of instruction's from different sites but yours covers them all, big well done and a big THANKS!!!

[MattBennett]

Cheers Dave! Will have to get one bought great guide. Will be using it soon!

[nick_182]

As everyone above said mate, thaks very much for all of your recent guides, they are a big help

[Mini_Nigel]

Originally Posted by Dave KG

Polishing with the PC7424

Great stuff Dave, but I don't think you'll get a shine on that shag-pile


Nige