Continuing our series of blogs focusing on frequently asked questions, we’re going to present two e-mail enquiries about machine polishing issues; specifically machine choice and pad choice. We receive a lot of enquiries about these topics, so hopefully what follows will be useful. However, as always, if you have any remaining questions please feel free to fire away below and we’ll do our best to help.
1. “I’ve been detailing for a couple of years now and want to make the step up to machine polishing to gain further improved results. I’ve read on the forums where some people have gone straight to a rotary polisher with seemingly no problems. However, I notice you don’t recommend a rotary for novices such as myself and recommend a dual action machine. If a dual action machine is the best option, which of the three you offer is the best?”
You’re right; we don’t recommend a rotary machine polisher for novices. A rotary machine is capable of a very high work rate and, as such, can remove a large amount of paint in a very short space of time. In comparison, a dual action machine will, generally speaking, remove far less paint than a rotary machine, due to its lower work rate. This is the main reason why a dual action machine makes more sense for the amateur user; it is fundamentally safer.
While it’s true that a dual action machine isn’t so fast when it comes to correction work, there seems to be a little bit of a myth on some forums that a dual action machine can’t correct paint to a very high standard. This is untrue; in fact, if used properly, and with the right pads and polishes for the task in hand, a dual action machine can correct just about anything a rotary polisher can – only deeper marks on very hard paints will prove tricky.
Going back to the higher work rate of a rotary machine; this not only results in a higher rate of paint removal and the risk of ‘strike through’ (complete removal of the uppermost layer of paint, usually the protective clearcoat) but also the rapid generation of a substantial amount of heat – excess heat build up on a panel can result in the pant being burnt; if this occurs the panel will need to be repainted.
Taking all these aspects into account, I’m sure it becomes a little clearer why we recommend a dual action machine for novices – the much lower risk, with the promise of very similar results, makes this a better option for a non-professional user. Regarding the three dual action machines we stock, there are some key differences between them…
Starting with the Kestrel DAS-6 machine; this is probably regarded as the benchmark dual action machine in the marketplace and with good reason. It’s tough, easy to use and quite inexpensive whilst also being capable of excellent correction work. The 500W motor is quite powerful and the machine is the ideal first step into machine polishing. For anyone on a tight budget, it offers excellent value for money, and comes with a standard twelve month warranty.
Next up is the Kestrel DAS-6 Power Plus machine; this is the newer, more powerful version of the standard DAS-6 machine. The key benefit of this machine is this extra torque provided by the 850W motor – on harder paints, where quite an aggressive polish and pad are typically needed for correction of severe defects, this extra torque keeps the head of the machine spinning, even under very heavy load. For softer paints, this extra power is unnecessary.
The Meguiar’s G220 V2 machine is the newest on the market, replacing the popular original G220 machine. This new machine is very nicely finished and quite lightweight. Whilst on paper it may seem underpowered (550W vs 850W) and expensive (£200 vs £149) compared to the DAS-6 Power Plus, it does feature ‘cruise control’, which ensures the head of the machine maintains the selected speed, regardless of the level of load.
In summary, there is no ‘best’ machine, only the best machine suited to a user’s needs and car paint type. In broad terms, the Kestrel DAS-6 and Meguiar’s G220 V2 are best suited to tackling soft to intermediate paints, while the Kestrel DAS-6 Power Plus is ideal for hard paints. However, whichever of the dual action machines you choose, so long as you match the pad and polish type to the job in hand, you should gain excellent results. As ever, if you’re not sure which is right for you; let us know and we’ll steer you on the right path!
John @ PB
2. “I keep seeing new types of machine pads on the market. I’ve always had great results with my current pads – they’re still in good condition as I only polish the car once a year or so. Surely there can’t be that much difference between pad types, or am I missing something?”
Pad type is a vital aspect of the successful polishing equation, and should always be matched to the paint type being worked on and the polish being used. All automotive foam polishing pads are made from flexible polyurethane foam, but the nature of this type of foam can vary considerably depending on specific aspects of the manufacturing process. Cutting to the chase, what is important from our perspective as detailers is the grade and cell structure of the foam used.
Grade governs how soft or firm a pad will feel (at any given thickness), while cell structure affects flexibility and how air and polish behave on (and within) the pad. Two different cell structures are commonly used; closed cell and open cell. In closed cell foams (also commonly called pre-polymer foams and non-reticulated foams), air and polish are unable to pass freely through the foam (i.e. it has no discernable pore structure). This means that polish tends to be held on the surface of the pad during use, and that any heat generated during the polishing process is not readily dissipated. Closed cell pads tend to be dense and generally quite stiff and inflexible at any given thickness.
In open cell foams (also known as thermally reticulated foams), the faces of the individual polyhedral bubbles formed during the chemical mixing process are removed by secondary heating (leaving only the bubble skeleton behind), which gives rise to an open pore structure through which air and polish can pass quite freely. This means that open cell pads tend to soak up polish more easily, and are able to dissipate heat far more easily. In addition, this removal of some of the foam material during the manufacturing process also results in open cell pads being less dense and more flexible at any given thickness, and also, somewhat surprisingly, more tear resistant.
Applying these characteristics to the real world, if you’re trying to correct hard paint with an aggressive polish, you’ll be best off using a firm, non-reticulated pad, such as a Menzerna Compounding Pad or a Lake Country Hydro-Tech Cutting Pad. This is because such pads offer a high degree of mechanical cut and a lot of compression resistance, which forces the polish into the paint surface more and gives better correction. If a soft, reticulated pad was used instead, it wouldn’t work the abrasives in the polish thoroughly enough, and correction would be poor. Furthermore, the abrasives may not break down properly, increasing the risk of seeing micromarring in the finish (micromarring is the technical term for fresh defects inflicted during the polishing process as unbroken down abrasives are moved around between the pad and the paint, leaving a faint pattern of very tightly defined swirl marks in the finish).
Conversely, if you’re trying to correct soft paint using a mild polish, you’ll be best off choosing a soft, thermally reticulated pad, such as a Lake Country Constant Pressure Light Cut Pad or a Meguiar’s Soft Buff Polishing Pad. This is because such pads offer limited mechanical cut and a reduced working time, because polish is able to soak into the pad and away from where it is being worked against the paint. As a result, the rate of paint removal is minimised, whilst still allowing a high level of correction to be achieved. If a firm, non-reticulated pad was used instead, it would not only cut the paint more itself, but would also increase the work rate of the abrasives in the polish, and thus potentially remove too much paint.
Pad choice does sometimes tend to be overlooked and I find many people are keen to switch their polish when, in fact, a change of pad would be best. The two are equally, and vitally, important to achieving proper correction on any type of paint. Best practice is always to use the least aggressive pad and polish for the paint type in question, but sometimes it can be difficult to know where to start. Our online guide to paint hardness, which is based on our own long term experience in our detailing studio, gives an indication of which pads and polishes will be best suited for the task in hand. However, if you’re in any doubt, let us know what type of car you’re working on and we’ll be happy to advise you further.
John @ PB