Surface Evaluation
Diagnosis is the key; not guesswork; examine the vehicle panels, a ‘bag-test will ascertain the need for detailer’s clay, and a 3M Sun Gun or a Brinkman light will help you find any evidence of surface blemishes i.e. swirl marks and scratches.
The most important first step in the process of paint surface detailing is diagnosing the paint surface; density of clear coat (hard or soft) or single stage paint, surface condition; ascertain the severity of the surface blemishes with an inspection light and the paint thickness available.
The paintwork should be evaluated with a paint thickness gauge to see what thickness of clear coat remains before you decide how much paint renovation can be safely carried or wither paint preservation would be the appropriate option, before you proceed, measuring with a paint thickness gauge will dictate the choice and abrasiveness of polish / compound for correction or renovation level required or indeed possible
Always follow the rule of starting with the least abrasive combination, i.e. a machine polish and the least aggressive foam or wool pad (working smarter not harder) The most important first step in the process of paint surface detailing is diagnosing the paint surface; density of clear coat (hard or soft) or single stage paint, surface condition; ascertain the severity of the surface blemishes with an inspection light and the paint thickness available.
Measuring with a paint thickness gauge will dictate the choice and abrasiveness of polish/compound for correction or renovation level required or indeed possible. Assess the correction level working through the range of polishes from the lightest abrasive upwards until the desired level of correction is reached. Selecting the correct pad/polish combination for the vehicles paint/defects can take just as long as the paint correction process
When removing defects from the paint surface, consider not only which polish/compound you'll be using, but how you'll be using it. Your choice of machine speed, pad construction, pad size and applied pressure will all impact the abrasive abilities of the polishing liquid.
Decide on a one, two or three step polishing routine and select a suitable pad. After testing a section to confirm this method, Select an area of 18 x 18-inches and tape it off with painter’s tape, as this is an optimal working section to perform a product test spot; this will help establish a process that will produce the best possible finish, once this is established repeat the process over the entire paint surface
Select a ‘typical’ area (one that represents the type of defects that you want to remove) and starting with the least abrasive polish and / pad combination and then proceed until the defects are removed. This is the polish/pad combination you’ll need to use
Rotary Polishers- a high-speed polishing machine, the high-end machines have a direct-drive with selectable electronic speed control that maintains a constant speed under varying loads conditions regardless of the pressure applied
· Porter-Cable 7428 - reliable , 10-amp motor, variable speed 0- 3,000 RPM, 9 Lbs weight
· Metabo PE12-175 – ergonomically sound, on/off switch, feathering variable speed 700 – 2200 RPM, 10-amp motor, 6 Lbs weight
· Makita 9227C –a reliable workhorse, ‘soft start’ trigger switch and variable speed 600-3000 RPM
10-amp motor, 6 Lbs weight
· DeWalt DW849– a reliable machine, 8 Lbs weight, 1000 – 3000 RPM,8-amp motor
Used mainly by body repair / paint shops or very experienced detailers to rectify more serious paint film surface imperfections using a Velcro backing plate, foam or wool pads of varying coarseness and an abrasive compound or polish to remove swirl marks, scratches and paint defects, using their high (revolution) speed and friction (heat) to enable compounds to abrade the paint film surface that requires more power /speed than a random orbital buffer can provide
Experience will teach you how your polish/pad combination ‘feels’ as it goes through the various stages; i.e. cutting, to polishing stage and finishing stages, where the polish lubrication has dried up, this is where you stop, wipe off the polished area, inspect the paint surface and either clean the pad, apply more polish or change it for a clean fresh one
Warning: Always use ground fault protection interruption (GFPI) when using any electrical device around water
1. ALWAYS stay focused on the job while using a rotary polisher.
2. Nearly every rotary on the US market today uses a 5/8 - inch / 11pi arbor spindle for backing plates. (non-US M14) I would recommend getting a hook and loop (Velcro™) backing plate and a 5.5-inch pad to start with as they are more easily controlled.
3. Masking the vehicle (Masking tape and Masking paper) pre-prep as if it were being ready for painting saves allot of cleanup time.
4. A rotary will usually ‘sling’, especially at the higher speeds used with compounds. Priming and using the correct amount of product on the pad will also help minimize ‘sling’ and keep product usage to a minimum.
5. Learn to steer the machine (not fight it) a lighter more relaxed grip will help to master the process
6. Practice (steering) control of the rotary polisher, on different panels, different orientations (i.e. flat –hood roof and trunk, vertical - doors and fenders) as differing techniques of machine movement must be adopted.
7. Clean your pads before you use them, or start out with a new pad; use a soft toothbrush for foam, and a spur for wool. As a general rule, the more aggressive the polish, the more often you'll need to clean out your pads. I clean out my pad after every panel when compounding.
8. Oxidized paint and polish residue accumulates on the pad surface and will negatively impact polish results
9. Clean (or replace) you pads frequently – a clean or fresh pad will restore the intended abrasive ability, where as a saturated foam pads abrasive ability will decrease (note dried or caked on polish will increase the risk of surface scratches) clean often with a soft fairly stiff brush or pad spur (Duospur).
It is very important that you keep your working pad clean; as you go over the surface the removed polish and oxidation is being absorbed, which will become large abrasive fragments and will interfere with the cutting ability of the diminishing abrasives as the old polish debris will not break down a will affect the desired surface and may also be the cause of surface hazing
10. Practice centering the pad on the rotary; spin it at a low speed to ensure it is properly centered. Higher RPM speeds can give the illusion that it is centered as the centrifugal forces push the foam out slightly making it appear more centralized
11. Before commencing polishing do a test panel on the car, once you have achieved the desired results with the chosen polish/pad combination proceed
12. Diminishing abrasives- you need to allow the abrasives to break down (become progressively smaller) to create a great finish or you may impart surface marring, holograms or worse. When a polish "flashes" from a liquid paste to a light semi-dry haze; its colour changes from the polish colour to almost transparent; the polish has then broken down and is ready for removal. It is important to know when a polish has broken down because if you take it too far you (dry polishing) will re-introduce surface marring.
13. Conversely, if you don’t work diminishing abrasives sufficiently they will cause surface marring; this is due to the size of the abrasive and its cutting ability, once an abrasive has broken down it becomes very fine and will burnish the surface as opposed to cutting it
14. Ensure a ‘wet’ polishing film is always present between your pad and the surface. Swirls are usually caused by using an aggressive polish without breaking down the diminishing abrasives properly, or you may have used too much polish or it may have dried. To remove, spritz the pad with distilled water (un-primed pads can cause marring) do not add further polish) and re-polish using the polish left on the pad.
15. Holograms - A pattern of small scratches left in a finished paint surface by the pad or sander during the sanding compounding and/or polishing operation;
16. Are caused by not allowing a diminishing polish to fully break-down i.e. insufficient work time, the product should become somewhat transparent (i.e. looks like thin cover of Vaseline) A finishing foam pad and polish should remove them
17. Dry buffing
· Using too little polish
· Working a product for too long
· Using an overly aggressive pad
· RPM speed too high
· Pad angle (keep the foam pads flat) etc.
18. Some professionals prefer to polish the surface first in a side-to-side motion and then in an up-and-down motion. I was taught (many years ago) to polish in a figure-8 movement and it's now second nature to me. Side-to-side and up-and-down motions seem awkward to me now. Try both motions and stick with the method that is comfortable for you.
19. Edge (spin-off) – a light sensitive approach is essential, using only the weight of the machine, on vertical panels just enough pressure to maintain contact with the surface (without applied pressure) tilt the contact edge of the pad a few degrees so that only the leading edge of the pad is in contact with the paint surface.
Make sure the leading edge (right-hand side) of the pad is rolling off the panel so that would mean the right side of the pad is rotating off the panel. If you have the trailing edge (left side) of the buffer on the edge it will tend to strongly force the machine out of your hands and burn the edge almost instantly.
A smaller pad surface contact area will increase friction heat so adjust machine speed accordingly As far as the edging goes; normally you aren't going to find excess marring and scratching over the edges. So if your machine in steps (and you definitely should be) save the edges for you last stage of polishing. This way you’re using a least aggressive product and pad with less pressure.
20. Knowing when a polish is fully broken down comes with experience but a good yard stick is when the polish has gone clear and is very easy to wipe off. Holograms or micro marring are again imparted due to polish that hasn’t been properly broken down or too high speeds. Following the advice above or below should cure these.
21. Intermediate polishing horizontally, final polishing vertically, so if there are buffer trails, they will be able to tell which process created them.
22. ‘Buffer hop’ is when the rotary jumps across the paints surface usually due to insufficient polish/lubrication and as the foam pad grips the paint it jumps. Try spreading the polish more evenly across the pad, add more polish, distilled water or quick detailer (QD) This can also be caused by a bogged down pad – clean / spur / replace pads often.
23. For the neophyte user, I would suggest starting out by using a smaller pad, 6.5 – inch I have even found 4- inch pads to be very useful for polishing small tight spaces and smaller panels.
24. Speed – With a rotary, as you move away from the centre the pad is moving faster to complete a revolution as it is covering a greater distance towards the edge of the pad and therefore producing for friction, the higher the RPM the friction increases along with the abrasive power. Reducing the size of the pad reduces the faster moving area, reducing these factors, so the speed needs to be raised to make up for this.
You can see this in action if you drop the pad size from 6inch to 4inch, but keep the speed the same you'll always see a drop in cut, where before you may have been getting perfect correction it'll drop off. Up the speed and the previous results return.
High RPM i.e. >1700 will cause high surface temperatures (should be limited to 1000F / 300
25. 115.F / 45. C < spot temperature will damage clear coat to the point that it requires repainting.
26. A rotary requires no more pressure than that required to ‘hold’ it on the paint surface
27. Always tape pinstripes; it doesn't take much to wipe them right off the paint, or thin them out
28. Inspect your work under full sun (or use a 3M Sun Gun®) Holograms, fine marring hooks, etc. are very difficult to see under man made light. There's nothing more frustrating than having to strip off your LSP and re-do.
29. Remove all polish residue and oils before applying your LSP. This is a general rule of thumb for best results across all product lines, and you will notice an overall improvement in the clarity, gloss, and overall 'look' of your finish.
30. If you're new to rotary polishing start off by only using finishing pads and do not exceed 1500 RPM < faster is not better and it may cause you problems. Let the rotary do the work, you'll be surprised at what you can correct with a finishing pad and a mildly abrasive polish.
31. When you shut down the machine never let the pad stop on the surface. Bring the machine to the closest edge of the panel and slowly let it roll off with an angle facing inward to the panel, this will help prevent marring.
32. One of the biggest problems when using a rotary is product sling. However when using highly lubricated polishes sling is a sign that you’ve used too much polish or you have turned the speed up to too fast, too soon. No matter how much you try and avoid it you’re still going to see it. Cover areas you don’t want to be covered in product and mask off trim with blue painter’s tape if necessary and cover windshields or other vehicle parts with towels. Be careful around moldings, antennas (aerial’s to us Brits ) and other trim pieces
33. Do not to put the chemical on the pad as the product will sling. The rotary should be in constant motion, if you're putting the chemical on the pad, then that means you are starting from a standstill. That also means that the rotary isn't spinning when it touches the paint, rather you are accelerating up to speed while already on the paint. Another reason you want to put the chemical on the paint is that the chemical is acting as a lubricant between the pad and the paint.
34. Do not remove compound or polish grit/dust with a dry towel; as this will cause surface marring. Use a damp Micro fibre towel with minimum downward pressure and a no-rinse type product (Optimum No Rinse) that contains surfactants to encapsulate the debris
35. Moisten the pad with distilled water as it stops the pad absorbing too much product and provides a longer ‘working’ time.
36. A smaller pad on the PC has more cutting power than a smaller pad on the rotary An 8- inch pad on the rotary will have more cut than a 6- inch
Pad Trailing and Leading Edge
Looking at a pad that is on the paint surface; the trailing edge is the left side (between 7and 5 o’clock) and the leading edge is the right side (between 11 and 1 o’clock)
A light sensitive approach is essential, using only the weight of the machine, on vertical panels just enough pressure to maintain contact with the surface (without applied pressure) use a lower speed 1000 – 1200 RPM and keep the pad moving. Tilt the contact edge of the pad a few degrees so that only the leading edge of the pad is in contact with the paint surface. Make sure the leading edge (right-hand side) of the pad on a rotary polisher is rolling off the panel so that would mean the right side of the pad is rotating off the panel
If you have the trailing edge (left side) of the buffer on the edge it will tend to strongly force the machine out of your hands and burn the edge almost instantly.
Optimum Micro Pads and Hyper Spray – Shake the polish and then apply two sprays to prime the pad and then use one spray per panel. Random orbital polisher; spray the pads perimeter as the product will migrate to the centre during use. Rotary polisher; spray the centre of the pad as centrifugal motion will spread the polish outward
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