Then most recent detail from Bryan and myself (Stu was working during this one, alas) was a 21 years old Zinnobar Red BMW M535i belonging to a good friend of Bryan. A car from my youth this one as my neighbour had one when I was young, I've been lookiong forard to this detail - a car that, for me personally, is a proper BMW. (I love the E21, E28, E30 and the E34! ) The night before, Bryan prepped the car ready for machining by washing and claying... The car was ready in the morning when I arrived for machining... This car was going to be a challenge... not from the point of severe defects, although they existed, they were quite isolated. This car's challenge was hugely varying paint thicknesses from panel to panel: readings as low as the 60s (um), and as high as 120-130um. Well - the car is 21 years old, some paint variation can be expected but this doesn mean treading crefully and changing required polishes as we go along: this car saw everytying from Menzerna PO85RD Final Finish on a finishing pad to Menzerna S34A Power Gloss on a cutting pad! Down to business, I started on the bonnet while Bryan fnished taping up. Defects here were medium swirls, some RDS - in all fairness, pretty damn good nick for a car of its age: Testing here revealed the best combo on the 90 - 100um thick paint was Menzerna PO85RDE3.02 Intensive Polish applied on a Meguiars W8006 polishing pad as follows... 600rpm, light pressure, 1 pass: Spread the polish 1200rpm, light pressure, 4 - 5 passes: Beginning to work 1500 - 1800rpm, light - medium pressure, 8 - 12 passes: Working the polish 900rpm, light pressure, 2 - 3 passes: Refining the finish This process delivered the following correction and finish results: Being solid red, real care must be taken when finishing as the colour will punish the slightest hologram or lack of clarity. A finishing polish was kept on hand, but I found that it was not necessary on this paint providing the abrasives of the Intensive Polish were correctly worked. A finishing polish was required on the wing however... Similar defects: However, much thinner paint! 60um in places. The IP on the rotary had shifted around 5um: you could see it on the paint gauge. So, this was out for the wing! Out with the Porter Cable 7424 and Menzerna PO106FF Final Finish on a 4" SFX-2 polishing pad. Gently gently was required here, the polish was worked as follows: Speed 2, light pressure, 1 pass: Spread Speed 5, 4 - 5 passes, medium pressure: Beginning to work Speed 6, 10 - 15 passes, medium pressure: Working the polish thoroughly The results from this were as follows: Good correction I felt, RDS remained but softened, but with the paint thickness as it was, they just had to be left. Finish was also good, and this is a key point with the PC on paint like this. A solid dark colour will show every little mark, including very fine micromarring which some metallic flakes can hide. If a polish is not thoroughly worked by PC, very fine micrmarring will be left, looking like little half moon shaped scratches all over the finish, completely ruining its quality. So great care was taken (and should always be taken on any finish) to ensure the polish was thoroughly worked to avoid any induced micromarring. By contrast, the passenger side of the bonnet had severe RDS marks, and a healthy 120um of paint: So to the other end of the scale of machine correction: Out with Menzerna S34A Power Gloss, and a Meguiars W7006 cutting pad. Applied as follows: 600rpm, 1 pass, light pressure: Spread 1200rpm, 2 - 3 passes, light pressure: Begin to work in 2000rpm, 10 - 12 passes, light to medium pressure: Fully work 1200rpm, 2 - 3 passes, medium pressure: Refine Higher speeds uses here, but I find I get a little extra from the PG at the higher speeds. This was followed with Menzerna PO85RD Final Finish on a finishing pad to refine the finish, appled as follows: 600rpm, 1 pass, light pressure: Spread 1200rpm, 4 - 5 passes, light pressure: Begin to work 1500rpm, 8 - 12 passes, light pressure: Working 1200rpm, 1 - 2 passes, light pressure: Refining 900rpm, 1 - 2 passes, light pressure: Refining The results of this: RDS still there, but far less severe and a good gloss returned to the red paint: The car's owner has ***** Ital, so this was the LSP that was chosen by him. The paint was pre-cleansed using Victoria Lite Cleanse (seems to me to be just as effective as HD Cleanse, yet much easier to use), and the Ital applied. Meant for Italian paint apparently...... pah, rubbish! Its good on any paint type, and added a nice wettness to the red - a very small nice wettness, but nice none the less Owing to the short winters days but the desire to see the car outside and completed, the front half of this car was done to a finish so daylight photos could be taken to see the finish before the car was rolled back in to be completed... So, the after shots: the car is done to a finish from the front to the end of the front doors (machined beyond this)... The interior was also given a quick once over: hoovered, plastics dressed, glass cleaned - no extractor was brought out for carpets... And one last "artistic pic" back in the garage once completed:
Very nice results, vehicle looks great. Just curious was this vehicle single stage or did it have clear coat....sorry if I missed it, I'll go back up and read it again. Oh another question for you Dave, with all the vehicles you have detaild at what point do you consider it to be unsafe to polish a vehicle. I mean if you get 60microns can you still polish at 50microns or 40 microns...I've always been very cautious when I see 50 microns...but just curious and I'd love to hear your opinion. Very nice detail, thank you for sharing with us eace:
you give the most advice of anybody on the net, thank you for taking the time to explain your polishing technique.
This car was single stage paint. Regarding how thinly you can polish, it really depends on what car you are working on and how thick the layers of paint are... Its impossible to know the thickness of individual layers with the paint gauge I have (and indeed, most gauages) so you have to play a few tricks and err on the side of caution... Measuring the thickness on the inside of the door gives you a clue as to how much paint there is with a single layer of clearcoat vs. multiple layers of clearcoat on the body panel. This gives you a rough idea of the amount of paint there is to play with. Its also important to note though that you do not want to be taking the clearcoat down to being very thin, as the thinner it is, the less well it adheres to underlying paint and the more likely it is to flake off... and if you leave a car with a critically thin amount of clearcoat, you wont ever be able to machine polish the paint again in the event of more swirls being added.
Thank you for sharing Dave eace: Yes, I agree with you. Even the PosiTector 6000 wont give me individual layers it just gives me total layers. There is a gauge that will give you individual layers but it's over $10,000.00 and well I'm not ready to purhcase that machine just yet. Any who, I understand what your saying...but thank you for the tip the one about taking readings inside the door...never really thought of that but it makes sense :thumb:
