Using D/A on non-flat car surfaces

[RyanNowlin]

Am thinking of purchasing a D/A polisher and have watched all the videos, but they are always working on a flat surface like the hood of the car. What about for parts of the car where there are significant curves, etc. -- is it best to just do these by hand?

Thanks,
Ryan

[Amature Detailing]

Re: Using D/A on non-flat car surfaces

Am thinking of purchasing a D/A polisher and have watched all the videos, but they are always working on a flat surface like the hood of the car. What about for parts of the car where there are significant curves, etc. -- is it best to just do these by hand?

Thanks,
Ryan

Using the D/A on curved parts of a car is perfectly fine. The G110 v2 wont burn paint like a Rotary would with improper experience. It was designed not to. Your results would be best with the meg 4" pads/backing plate on the small curved area's like the A-Pillars and such.

[Shawn T.]

Re: Using D/A on non-flat car surfaces

Using the D/A on curved parts of a car is perfectly fine. The G110 v2 wont burn paint like a Rotary would with improper experience. It was designed not to. Your results would be best with the meg 4" pads/backing plate on the small curved area's like the A-Pillars and such.

Agreed. 4" pads work great on those curved surfaces but you could also roll the pad over the surface. Instead of going side to side, go up and down on the curved on the surface keeping as much of the pad on the paint as possible.

[subjectzero]

Re: Using D/A on non-flat car surfaces

I think the only areas you would have worry doing by hand are where there are grooves in the body molding that run the length of the car under the windows. Unless you have some kind of bonnet that will mold itself to the structure of the surface. (If you do please share where you got it! I want one!) I also have a small 6" diameter section under my mirrors I have to do by hand because the angle will not allow the buffer reach.

[Black1]

Re: Using D/A on non-flat car surfaces

You won't have any issues with polishing curved/rounded surfaces while using a D/A. If you are working on the Porsche in your picture, the small areas around the front bumper cover and under the rear wing would have to done by hand, because you can't fit the D/A in there.

You just have to be careful not to "roll" the pad over (exposing the backing plate) on the paint while using the machine. But that is actually pretty hard to do when using the new Meguiar's 2.0 pads. Other than that, just take your time and have fun! You'll get the hang of it in no time.

[Michael Stoops]

Re: Using D/A on non-flat car surfaces

Have you read through D/A Buffing 101 – An Introduction to the G110v2 and similar tools yet? It should help you out quite a bit if you've never used a D/A before.

The images below are taken from that article. See how the centerline of the pad stays in contact with the curved panel in the animated image below, rather than using the edge of the pad? That's what you want to do on convex surfaces.



Going to the edge of the pad on a convex surface like this will cause the pad to stop rotating, and you want that rotation.



Now, when you get to some concave surfaces you can't keep the centerline of the pad in contact with the paint because the edges of the pad will be on the upper portion of that concave panel and the center of the pad won't be touching the paint. In those cases you want to sort of roll into the concave from multiple angles in order to reach it all. Small pads certainly can help with this, depending on how small an area you're trying to reach.

Paying close attention to the rotation of the pad is key. Some people like to make a few reference marks on the backing plate with a Sharpie or a piece of masking tape so they can more easily see the rotation.

[mattya802]

Re: Using D/A on non-flat car surfaces

Now, when you get to some concave surfaces you can't keep the centerline of the pad in contact with the paint because the edges of the pad will be on the upper portion of that concave panel and the center of the pad won't be touching the paint. In those cases you want to sort of roll into the concave from multiple angles in order to reach it all. Small pads certainly can help with this, depending on how small an area you're trying to reach.

Paying close attention to the rotation of the pad is key. Some people like to make a few reference marks on the backing plate with a Sharpie or a piece of masking tape so they can more easily see the rotation.

This is the issue for me. Seems there are some areas you just can't get to from whatever angle you try...Well you can, but the pad stops spinning (going by the sharpie mark I made on my backing plate). If the pad has stopped spinning, that means I'm not actually inducing any "cut" right? I should just do that area by hand then?

[Michael Stoops]

Re: Using D/A on non-flat car surfaces

If the pad has stopped spinning, that means I'm not actually inducing any "cut" right? I should just do that area by hand then?

You're still getting some, but it's greatly reduced. Still, for those few tight areas you may still get all you need, especially if you increase the pressure. It really comes down to adapting as you go and sort of forcing the issue with the tool - to some degree at least. But sometimes it does come down to having to do some small spots by hand if the buffer simply won't reach into the area.

[GaulGW]

Re: Using D/A on non-flat car surfaces

I am not sure I understand the instructions for concave sections. I have a 1967 Mustang and it has a concave area that runs down the length of the car on both sides including the front and rear fenders as well as the door. The radius is pretty large on the fenders but pretty tight on the doors.

Will I be able to do these areas with a D/A? Will I need special small pads? Is there a special technique or angle I will need to use?

[BillE]

Re: Using D/A on non-flat car surfaces

You SHOULD be able to do those area fine. One nice thing about a DA is, it is pert near impossible to burn the paint in the 'closed-in' areas.

Give it a shot, the worse that will happen (my thinking) is those area won't be a 'nice' as those on the flats. Then, you want to go down to 4" or just my hand.

Bill

[Michael Stoops]

Re: Using D/A on non-flat car surfaces

Those areas on the fenders and quarter panels of the Mustang should be no problem at all. On the tops of the doors you should still be able to get the edge of the pad (not the vertical edge, but the outer edge of the pad face) to conform in there and get the job done. It's going to feel a bit odd at first but you should be able to work the pad around there with all the compression a foam pad will take.

[GaulGW]

Re: Using D/A on non-flat car surfaces

I think I understand, but let me make sure. On an earlier post in this thread,you show an example of a pad on its edge on a convex surface and say that is what not to do, but on a concave section that might be the only way to get into the area. The picture also shows the part of the pad you want to make sure stays in contact with the surface, as opposed to the outer vertical edge or rim area.

When I am working on the edge of the pad like it shows in the "not to do" picture, do I need to use light pressure to make sure the pad keeps rotating or can I get better results with more pressure and just rely on the oscillating motion of the pads?