Started to do the work on the bed retoring my '55 F100 and the sides seem to have a couple waves in it. I'm working on repairing the bolts holes as seen in my other thread, but wanted an idea of how to get it flat and smooth when i'm done. It seems on a lot of shows on TV they put "skim" coats on the entire panel then sand it. What is a good way to get it all smooth? I was thinking of black paint, but with all the rust and problems, not sure its such a good idea, lol.

 

Use a long sanding board for the flat areas. Work in a cross hatch pattern. The idea is if the board is long enough it wont ride in and out of the low spots but knock down the high areas , you fill the low areas and sand again and keep repeating until eventually you get the flat panel you are looking for.Keep in mind black paint will show every little imperfection.

 

...Jack

Take a look at this forum www.metalmeet.com for lots of info regarding metal working which is the foundation for a great paint job.
Bruce

 

mississauga is right on.
You need a really long sanding block about 1/3 the length of the panel you are working on if you want all of the waves out. For a bed side that would likely be a sanding block about two to three feet long. I would compromise and use something about 12 inches long unless this is going to be a show quality truck.

Make sure the metal is straight, you'll never get it straight if the metal underneath the filler is wavy. I avoid putting the filler on in patches. As you mentioned, a skim coat over the whole panel is the way to go.
I ussually put an entire skim coat of filler on the panel after straightening the metal...sand... patch any visible low spots, and then thin the body filler with polyester resin and put on another lighter skim coat for the final sanding.

For the first rough sanding I will use 36 or 40 grit paper, but for the final skim coat I start with 80 or 100 grit. the finer paper slows me down, and helps keep me from making mistakes. I also do all of my sanding by hand. Power sanders are great for speed, but if you want it absolutely straight, do it by hand.

Lighter colors will hide any mistakes, and choose something with a lower gloss. Shiny paint shows ripples. It doesn't have to be flat paint, but stay away from glossy clear coat if the panel isn't perfect.

The curved panels (rear fenders) are going to be harder to get straight. I like to use old mouse pads, the really thick ones that were popular a few years back, I cut them up and use spray glue to glue two peices together. When dry just wrap the sandpaper around the flexible block and start sanding. The rubber mouse pads are flexible enough to follow the curves, but wont allow your fingers to dig in a mess up the curves.
They make really expensive sanding blocks for this but I'm cheap, and mouse pads are free.

Keep trying, you'll get better every time. I'm better at sanding today than I was a week ago.

 

You'll find long boards (8" to 36") on my website.