I posted this on LCOOL but others may like the info on here.
Disclaimer: I run a professional commercial car detailing business. I dont advertise for retail work as i work almost exclusively for car dealers. The info below is not to pimp my business in any way.
I was asked a question on machine polishing by a member and as the info may benefit all ill answer it in here. Members name removed (unless he wants to be known).
Originally Posted by anon
Hi Stewart, I was wondering if you could give me some advice on how to use a buff machine. I bought one to buff the scratches out of my car at the paint supplies shop. Watched some tutorial videos and thought it looked straight forward. It has a hard foam pad, I'm using septone Mr Buff cutting(?) compound. I struggle to hang on to it, it has a quoted speed range of 1 to 3 thousand RPM, I have it on number 5 out of 10 so I figure that's around 2,000rpm. Everyone on Youtube looks like the buff is just gliding along on the polish. I'm a pretty big/strong bloke and I'm hanging on like crazy to prevent it throwing along the panel, if I try to change direction off it goes. I'm not sure if it's relevant but I have the handle on it that causes me to hold it over the centre of the spinning pad, tomorrow I'll put the side handle on and see if that gives me more control. My young bloke pulled out a little Black and Decker polisher he'd bought, we tried that, no problems to control, he finsihed off the panel with it and cleaned up the mess I was making? It has a lambswool bonnet on it but the guy at the shop said foam vs wool is just personal preference, a bit like Ford vs Holden he said. I just want to work out if it's me or if the guy has sold me dud? Any tips would be appreciated cheers anon (we were trying different techniques and my son covered the foam in compound and turned it on before contacting the panel, I was standing beside him and I'm still trying to get compound out of my ears and nose)
OK, ill split this into sections (ill come back to edit more info in as i get time)
Types of Machine polishing.
RO or Random Orbital
A RO is more commonly seen as a sander. Most move around 5mm in a random action but dont rotate. Very safe to use, dont create a lot of friction and hence very little heat but also take a long time to achive anything. If you have use a RO for sanding then bought a belt sander you will know the differance in machines. A decent RO for detailing needs to move at least 8-10mm. The $30 ones from supercheap etc and completely useless and doing it by hand is faster. Dont waste your money. Most decent units start around $150+. Most 6" ones with a decent throw will do the job.
This one isnt bad. (no affiliation with these guys nor the products)
Rotary's can use a 2" to 10" pad. As the name suggests, they rotate but dont oscillate. This means they can generate more heat, work faster and cut better than the RO will. They are also much more dangerous and a misstep will find you at a panelbeaters for a respray. In the right hands, they will do a far better job.
What is a Polish and why do we need it?
Polish is an abrasive, it is not there to protect the car. The idea is to get the surface as smooth as possible. The smoother is is the more it reflects and the better the shine. The other advantage is the smoother it is the harder it is for anything to stick to it (ie dirt). Old white oxidized paint (that is more yellow than white) will actually act like velcro to contaminants and draw them into the paint. Have you seen the ad on TV where they stick a piece of chalk into food dye? Thats what your paint does to mud and dirt.
Do i wax, polish or seal? Why?
Polish is to smooth the paint by an abrasive action. It doesnt do anything else except maybe cleans a little too. There are as many grades of polish as there are grades of pads. Different combo's of polish/pads will work differently on different cars. Polishing can also be refereed to as "compounding" and polish as a "compound" (usually by our USA friends)
A sealant is to protect the paint, it doesnt cut. It can act as a synthetic wax to enhance the shine and often lasts a lot longer than wax. Being synthetic a sealant will generally stick to the paintwork better than a wax and last longer. 4-6mths at best.
Wax is a natural product (from a palm tree). Remember the talk about smoothness? What a wax will do is fill any rough paintwork and give the impression the paint is smooth. Its almost like a temporary clearcoat. When it looks smooth is shines. The better quality the wax the nicer the shine (within reason). Being a natural product it often only lasts a few months at best before its washed away
Both a wax and a sealant can also contain UV protectors. Marketing companies will often call a sealant or a wax "polish" or polish a wax and generally assist with confusing you.
Most if not all products advertised as paint protection are nothing more than a sealant and an insurance policy when damage does occur. The products themselves are often very cheap, poor quality and last 3-6moths at best. NOTHING on the market, anywhere in the world will protect your car for "years" and ensure you wont ever need to polish it again. (remember, Paint protection isnt a polish). These products are designed for one thing and only one thing. To make dealers money. The policies are so full of holes its unlikely a claim will ever be made and by that time the dealer wont want to know and passes the problem to the "insurance company" called XYZ paint protection who finds you didnt abide by their conditions so warranty on the product is voided. Not only dont these products work as they say, they are no longer even on the car after 6mths. Spend a few $$ on decent quality detailing products, a quality sealant and a wax and the car will be in far better condition 10yrs later than any paint protection scam.
(Discliamer: I do apply paint protection for dealers. I make very good money from it. I DO NOT sell it to anyone who comes direct to the shop.
What Pad do i use?
Wool has been around for years and is still used in most panel shops. Panelbeaters arent detailers and want to work fast. Wool is also fairly course so on an oxidised paint it will cut quite quickly but it wont bring the shine up that a softer pad will. Very few professional detailers will use wool anymore as the tech in foam pads means any level of aggressiveness or softness can be achieved.
As stated, foam can be either very soft for no cut and just applying the sealant and quick shine right upto a very aggressive cutting pad for removing the harshest scratches and imperfections. Knowing which pad to use for what application can take years to master and with new pads coming out all the time what works on one car wont work on another. I have a range of over 50 pads from 2" to 8" for everything from glass to perspex, paint types and even some specifically for some brands of cars. For most people a medium pad and a soft pad will be enough. If your car needs a hard cut then its far cheaper to call in a pro as 1 small error when cutting hard can mean respraying a panel or bumper.
Most paint is around 80-150 micron thick. This will be made up of a clear coat, colour and undercoats. Toyota 4x4's are at least twice as thick as their 2wd siblings and in some cases much more. This means polishing wont hurt the car. A decent polish will remove at best 0.5-1micron, often much less so the horror stories of wearing out your paint from overpolishing is a myth. You can however burn the paint bring us to our next point.
Friction = heat. Too much friction and you can burn the paint. When this happens you can discolour it or it can be heated to the point that it comes off the metal/plastic etc and you now have a hole in the paintwork requiring repair. With a RO its almost impossible to do as its action is very mild. Its also why it takes much longer to achieve results. With a rotary it can happen in seconds.
Wash the car first
Claybar to remove contaminates.
Work in the shade not full sun
When using either a RO or rotary you wont need a lot of polish. a 10c sized dab on a applicator pad will do around 2-3sq feet of panel. If it splaters you have WAY to much.
Usually i put the dab onto the pad direct then dot it over the panel ill be working on to spread it out. remember, minimal is better as too much as it goes everywhere, clogs up the pad and is a waste of money.
A RO is the easiest to use. its simply a case of moving back and forth over the panel, first one way then 90 degree's to it. You should notice the polish begin to break down. Sometimes it will feel a little gritty and the more you work it the smoother the grit gets. The smoother it gets the better the shine. Some polishes will stay quite "wet" were others will turn to dust pretty fast.
BTW, if there is interest ill run a detailing class in Brisbane. Please note the disclaimer at the top, im not soliciting for work, i have way to much as it is.