Help on technique on paint correct plastic bumpers

Hi all,

Can you provide me some tips how to successfully paint correction (light swirls) on bumpers that are plastic w/ scratch resistance clear coat (i have a BMW)? Can I use the same pads and compounds to remove defects on the plastic bumper vs. metal door panel? Or should I never use a cutting pad on anything plastic because it will melt through the paint? Also I've been getting mix advice on moving the buffer. Some tell me to move it quicker than you would working on a door panel, some tell me to use same pace as you would working on a door panel.

All of these tips are confusing and I dont want to burn through anymore paint. Im using a dewalt849 with soft buff pads from megs. Currently i have SIP, 106ff, and Megs #82. Please advise.

 

I would use a yellow or tan meguiars pad and set your speed at 900rpm's. Mist your pad lightly with QD or water before beginning. Keep your pad flat and the buffer moving slowly. Buff until the polish flashes or turns clear and then remove residue with a good mf towel. Do not buff to long or until it starts to dry. I mostly use 6.5" pads and 4" pads on the tight areas like bumpers. Feel surface occasionally with your palm to make sure it is not getting too warm. I hope this helps.

Try first with just the 106ff and if that is not strong enough to remove what you are trying to then go to the SIP and finish with 106ff.

 

As far as I know, the paint on your bumpers is the same as the paint on the body of the vehicle. It's just what is underneath is that you have to be careful with.

I use the same pads and polishes, just at a much slower speed.

 

ya be alot more careful on plastic bumpers, they are so much easier to burn into..use same pad and polish though

 

I dont think you should be priming pads with QD.

 

Would you keep the same pace as you would do a door panel?
Would you also use a cutting pad on a plastic bumper?

 

A lot people have been telling me this just waters down the product.

 

i would turn the speed down on the buffer just a tad bit, but i would keep the same speed moving my hand motion, and yes using a cutting pad is fine

 

Prime your pad with a quick spritz of deionized water, no QDs.

 

I dont prime my pad with anything. But if you're going to, then use water, not a QD.

 

If your using a Dewalt I'd be very cautious of using a cutting foam pad. The Dewalt has lots of torque and foam pads produce lots of heat. I have noticed that correcting the plastic peaces is much easier compared to any other panel of the vehicle, not sure if it's just the extra heat that gets built up or if it has anything to do with the panel it's self that is made of plastic but that's just something I've noticed.

I personally just use the same combo (pad and polish) that I use on the rest of the vehicle on the plastic bumpers, yes lower your speed a bit and polish the areas at the same pace as you would be doing on the rest of the vehicle. I sometimes don't even bother lowering the speed but you get more heat build up, sometimes you need more heat to correct but that's what can cause you to burn through the clear and the paint.

Well just my opinion, hope it helps.

 

Thanks for the tips Nica. I guess the only way to perfect this technique is through experience. I recently got the dewalt to use on my BMW since the clear coat on it is so much harder than my Acura. My DA couldnt buff out anything with the BMW on the door panels, but worked well on the ACura.

From my older post, I was the one that riped through my buddy's prius' front bumper with the DA, however the DA didnt do any damage to my BMW front bumper. I think it was too weak, and didnt correct anything.

I went to a Meguiar's training class a couple days ago and asked the instructor how to approach issue this with the BMW front bumper, he responded and said Meg's went through 2 years of research investigating how mercedes/bmw clear coat worked, and suggested the only way to cut into it was to set it at 1700 and go really quick front to back with it. But you guys all say to lower the speed and work it the same way. I"m thinking this was a very aggressive approach that he suggested. I'm still heistant of what method to try next.

 

Well to be honest 95cent sometimes I'll go slow and lower the rpm's but sometimes doing this does nothing to remove the swirls, so I have to bump the speed up and use a soft pad like the 3M blue polishing pad or the megs polishing pad (kinda yellowing colour). Every vehicle is different yes, but it just takes a bit of trial and error to find that combo that works best for that particular vehicle.

1700rmp is not that fast but at the same time I agree with what you have been told, don't use the same pace as you would on the rest of the vehicle, you'll have to go a bit faster...a bit..you don't want to go to fast that you don't let the polish break down and end up with buffer marks or holograms. But yea just speed it up a big..mmm....I think I made a video of me polishing the 3M on the front of a vehicle...on the 3M I go a bit faster compared to the rest of the vehicle, you have to or else you'll damage the 3M....I'll look for the video so it gives you a bit of an idea as to how fast to polish...hang on.

 

Okay I found one of the videos I was talking about, again this is just how I polish, it works for me but may not work for you but hopefully it will help you.

 

Dont use as much pressure on plastic.

According to 3M, you arent supposed to use a polish on clear bras.

 

I talked to a 3M rep out at SEMA this year about polishing clear bras and he said it was fine to do. He said not to use any compounds or wool though.

*By no means does that mean he is/was correct*

 

On their site it says no abrasive polishes or compounds.

 

I wonder if they just tell the public not to to inorder to help them with less warranty claims?

 

Im going to play this really really safe and go with 106ff w/ white pad or even a black pad on the bumpers without pressure letting the machine do the work, but moving it faster than normal. What do you guys think?

 

Give the black pad a try, but don't think it will do any correction. You can't hurt anything.