I know I'm going to screw this up, so help. I just repainted and added clear coat to my '87 GT front and back bumpers. They really look good, but certainly not like the rest of the car. I have 1200 grit sand paper and wish to wet sand the areas. But, how much pressure, if any do I use? And while doing each bumper, how do I know when to say - looks great, stop sanding?

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If it were me, I would just smooth it out with the wet sanding, then polish it with a buffer. That should bring out the shine.

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________Marty

Make sure you use plenty of water while sanding. You will actually be able to feel a difference by hand. The surface should feel smoother. Don't sand too much, just enough to smooth things out and finish with a buffer. It should smooth out fairly quickly.

Heres a tip, put a few drop of dish soap in your bucket of water. Not much, just a few drops. This will help ease the sandpaper over the surface.

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________Marty

I'd actually use a little finer grit. I use 1500 grit, and there is a definite difference in the sanding scratches when buffing it all out.

As for pressure, once you start sanding, you'll find out what it takes once you start. Only use enough pressure to sand, but make sure that you apply even pressure. You should be using a flexible sanding pad with your sandpaper to keep the surfaces consistant.

Mark

You should be using a flexible sanding pad with your sandpaper to keep the surfaces consistant.

On bumpers?
Just put some liquid detergent in some water, fold up your sandpaper (1000-1500) and sand till it feels smooth. After it dries it should be dull. Then you need to polish to bring shine back. Go to a decent auto supply and the guys at the counter will help you out. They know what the shops are using and what works.

When you wet sand the clear, dry it off and you will see all little shiney dots where you havent sanded enough. When its the smoothest it can be, you can dry it off and it will all be a consistant dull whitish color. TIP...just sand flat and curved areas, dont sand sharp edges. The buffer will take care of all those by itself with no sanding. Make sure theres enough clear on it to start with....if you sand it and go thru to where color is coming up ( everything should be white while you sand ), you will have to start over painting it.

Also you dont have to get it perfectly smooth, just a good all over sanding will usually be enough. Even factory paint has a small amount of orange peel, even on $100,000 Mercedes.

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quote Originally posted by fuzz: On bumpers?

Yeah, on bumpers. You still need to control the pressure on the sandpaper, and if you are just using your fingers, you can cause uneven sanding.

Wetsanding and polishing are an art, just like spraying a car. Anyone can do it, but how it comes out is up to the guy (or gal) using the tools. That's part of the difference between a paint job and a good paint job.

You always have to ba careful on edges, and in some places using wetsand paper without the block is fine (such as small areas), but the block is important for flat surfaces.

Mark

If it's pretty smooth to start with, try to use 2000 grit. It will make buffing it out a lot easier. Definately be careful on edges. I was wetsanding a panel the other day (just for practice) and I bumped through the clear and the color coats on an edge. As Firefox stated, use a flexible sanding pad as much as possible. They're cheap and worth every penny.