orngez
04-12-2007, 03:25 AM
Thought I would share some of my experiences with using a rotary with everyone as a "I wish someone had shared this with me when I was learning" thread...if anyone has other techniques they use...I would love to hear them ..I'm not saying the way I do it is the bible to polishing...but it's they way I learned and it has worked just fine for me...if I am doing something backwards let me know...but I haven't burned paint using these techniques so it can't be that bad :p..as I come across more scenarios I will try and add them to the thread...these are basic ones that are common on most cars...
Lesson 1: The bumper
Probably the one area where I have seen the most paint burning...plastic has to be treated very differently than the rest of the body...the paint bonding is much different on plastic bumpers and speed is not your friend...painted plastic needs long working times and slow speeds...you are better off not fully correcting the bumper than trying to work some of the intricate "L" bend of a bumper...that or break out the pc or cyclo...
Here is an example of an "L" bend
http://www.autogeekonline.net/gallery/data/571/medium/Picture_009.jpg
This is where the horizontal face of the rear bumper meets up with the vertical face of the trunk lid...it can be very tempting to just use the vertical face of the trunk as a guide for your polisher...just remember it is very difficut to determine how much pressure you are exerting agains the face of the trunk with the side of the pad...I have seen the face of the trunk lid with paint burn before and the side of the pad is the outer circumference of the pad...which btw is the part that is spinning the fastest...its actually best to tape off the face of the trunk where the side of the pad will touch it..or just be mindful and keep away from the face of the trunk...it can be very easy for the pad to also squeeze in the crack between the bumper and trunk lid and the paint on that edge of the trunk lid can be burned of in half a second..
these rules are also true when polishing the trunk face and the side of the pad would meet the bumper...it is actually even more important to be careful in this scenario because the side and edge of a pad will burn throught the plastic paint much easier than it would the metal face of the trunk
Lesson 2: "Peaks, Hills, and Valleys"
These can be tough....any time the entire pad is not on the working surface is where things can get skittish...common spots for hills and valleys are on the hood...in the example picture the hood starts sloping downward and that back up and over the contour of the headlight...just remember that the greatest amount of paint is in the bottom of the "valley" adn the least amount is at the top...the one thing not to do here is to try to use the pad as a "bridge" across the valley...do not try to polish this area by trying to place the pad over the top of the valley and pushing the center of the pad down to polish the bottom/middle of the valley..instead work each "face" of the valley like in the picture...the edge of the pad should be in the middle of the valley and the pad should only be polishing one side of the "V" shape...in this case it is the right side...
http://www.autogeekonline.net/gallery/data/571/medium/Picture_008.jpg
Another good thing to do is before turning on the machine do an imaginary pass or two on the area...make sure you see what will keep the pad parallel to the surface you are working on because as you move close to the front of the car you are moving in more than one axis..also be aware not to use the valley as a guide for your polisher...do not push the pad into the middle of the valley...you should be trying to keep the weight of the machine directed at the "face" of the valley...the object should be to keep the edge of the pad just a little bit away from the very center...
When polishing a "Peak" where to faces meet to form a raised point...similar to the valley technique...you should polish each face of the Peak separately....you should be starting your polisher away from the center of the peak and move towards it..do not polish over the top of the peak or start you polishing at the peak...in the example pic I polished to the right of the peak and move my way left and stopped when reaching the middle...i did not continue to move left and allow the polisher to "roll over" the peak like a speed bump..you want to avoid polishing peaks as the paint even on a new car is often extremely thin...
http://www.autogeekonline.net/gallery/data/571/medium/Picture_007.jpg
(the center peak in this picture is where you see the scratch stop..you can see the center peak of this hood right under the flash)
Lesson 1: The bumper
Probably the one area where I have seen the most paint burning...plastic has to be treated very differently than the rest of the body...the paint bonding is much different on plastic bumpers and speed is not your friend...painted plastic needs long working times and slow speeds...you are better off not fully correcting the bumper than trying to work some of the intricate "L" bend of a bumper...that or break out the pc or cyclo...
Here is an example of an "L" bend
http://www.autogeekonline.net/gallery/data/571/medium/Picture_009.jpg
This is where the horizontal face of the rear bumper meets up with the vertical face of the trunk lid...it can be very tempting to just use the vertical face of the trunk as a guide for your polisher...just remember it is very difficut to determine how much pressure you are exerting agains the face of the trunk with the side of the pad...I have seen the face of the trunk lid with paint burn before and the side of the pad is the outer circumference of the pad...which btw is the part that is spinning the fastest...its actually best to tape off the face of the trunk where the side of the pad will touch it..or just be mindful and keep away from the face of the trunk...it can be very easy for the pad to also squeeze in the crack between the bumper and trunk lid and the paint on that edge of the trunk lid can be burned of in half a second..
these rules are also true when polishing the trunk face and the side of the pad would meet the bumper...it is actually even more important to be careful in this scenario because the side and edge of a pad will burn throught the plastic paint much easier than it would the metal face of the trunk
Lesson 2: "Peaks, Hills, and Valleys"
These can be tough....any time the entire pad is not on the working surface is where things can get skittish...common spots for hills and valleys are on the hood...in the example picture the hood starts sloping downward and that back up and over the contour of the headlight...just remember that the greatest amount of paint is in the bottom of the "valley" adn the least amount is at the top...the one thing not to do here is to try to use the pad as a "bridge" across the valley...do not try to polish this area by trying to place the pad over the top of the valley and pushing the center of the pad down to polish the bottom/middle of the valley..instead work each "face" of the valley like in the picture...the edge of the pad should be in the middle of the valley and the pad should only be polishing one side of the "V" shape...in this case it is the right side...
http://www.autogeekonline.net/gallery/data/571/medium/Picture_008.jpg
Another good thing to do is before turning on the machine do an imaginary pass or two on the area...make sure you see what will keep the pad parallel to the surface you are working on because as you move close to the front of the car you are moving in more than one axis..also be aware not to use the valley as a guide for your polisher...do not push the pad into the middle of the valley...you should be trying to keep the weight of the machine directed at the "face" of the valley...the object should be to keep the edge of the pad just a little bit away from the very center...
When polishing a "Peak" where to faces meet to form a raised point...similar to the valley technique...you should polish each face of the Peak separately....you should be starting your polisher away from the center of the peak and move towards it..do not polish over the top of the peak or start you polishing at the peak...in the example pic I polished to the right of the peak and move my way left and stopped when reaching the middle...i did not continue to move left and allow the polisher to "roll over" the peak like a speed bump..you want to avoid polishing peaks as the paint even on a new car is often extremely thin...
http://www.autogeekonline.net/gallery/data/571/medium/Picture_007.jpg
(the center peak in this picture is where you see the scratch stop..you can see the center peak of this hood right under the flash)