Remove Scratches, Detail Your Truck and Other Secrets
Updated April 28, 2008
You won't get deep scratches out without speed and pressure. Some guys are really good with a high speed buffer but you can burn the paint or buff it down to the metal if you don't know what your 're doing. High speed buffers with lambswool pads generat a lot of heat. Once you burn through you'll have to repaint the spot which will end up costing you way more than a good professional buffing job. If you decide to go the buffing route I'd take it to a detail or body shop that has insurance. If they burn through then they have to fix it. I wasn't happy when I burned the whole edge off the front wheel well below right after I painted the whole truck..
The right way to really get all the scratches out is to wet sand the finish. I painted my truck back in October 2004 at a friends shop who restores 50's era Rolls and Bentleys. He showed me how to get scratches and orange peel out of the finish. The way they get the super paint jobs on the luxury cars is by using tons of labor. After they paint the car, the whole car is wet sanded and put aside to dry for a few months. Then it's wet sanded again and polished.
If the scratch is too deep; all the way through the paint to the primer you have to repaint the spot. There's no way around it. Last year I got back from Colorado and decided to wet sand a couple of spots. My truck is white and the primer is Gray. I ended up sanding out a deep scratch and before I knew it I was into the primer. You can only take out scratches in the surface of the paint or in the clear coat.
Here's what you do: You have to wet sand the area with 1000 grit until there is no more orange peel and the finish is flat. If it's brand new paint use 800 to start. On flat surfaces you use a flat rubber sanding block with the holes. The action of the sandpaper over a block with holes "provides multiple cutting edges, creating a 30% faster cutting surface".
On curved surfaces you use a block that has a soft foam back. Just Google the names of the blocks and you will find them available at a bunch of places. They cost about 5 to 8 bucks each.
The little black squeegee block is a bondo / glaze spreader.
If you really want to be careful take masking tape and tape the edges to protect them from sanding the paint off. Dunk the paper and block into some water. It doesn't hurt to put a few drops of dishwashing liquid in the water. Very lightly start working a small area in a circular motion. Keep the area wet Every so often run a squeegee or a small square of rubber across the surface to see which areas are shiny and which are dull. The shiny areas are low spots that haven't been sanded. Keep it up until the whole surface is uniform. Once again, be careful of edges. It's easy to sand through the paint on an edge. (There's less paint on the edges).
Once the whole thing is uniform you wet sand with 1200, 1500 and 2000. The other papers just take out the scratches from the paper before. For a Hummer you can probably bypass the 1500 and 2000. Just about every Hummer I've seen has a certain amount of orange peel. If you do a good job of wet sanding the area won't match the rest of the truck; it will be better.
Then buff with compound using a slow buffer at 600 rpm like a Makita 9227c with a 3m foam wheel (15.00). I use 3m Perfectit Rubbing Compound 05973.
The buffing pad should be slightly damp but not wet. If the pad is dry sprinkle a little water on the pad and rev the buffer up to a high RPM to throw off the excess water.
Squirt a line of compound on the truck and smear it around with the pad to spread it around before you start buffing. Always buff with light pressure moving the buffer around and run the buffer so the wheel is always turning away from an edge. This means that the rotation of the buffer should be pushing compound 'over the edge' of the corner.
The Hummer is hard to buff because it has so many edges and rivets. I'd stay away from the rivet heads completely until you get good.
To finish it off use 3m foam polishing pad Glaze 50031-05995 (for light cars). This product has fine abrasive and will polish the finish. It's best to use a separate foam pad for each compound.
This is the foam backed polishing pad. Get the rounded edge pads. They make another pad for compounding which is a 3m 05731. These pads sell for 15 to 20 bucks.
You will need a velcro Perfect-it backup pad 05718 or 3M Hookit Pad 05717 for your buffer. These are between 20 and 40 each.
I have a white wagon. If you have a dark color they have a dark glaze. You can get these products at shops that sell automobile paint. The pads compound, sandpaper and glaze will cost you around 100 and a Makita buffer is 200. Here is a picture album from my painting article showing what we did and showing when I sanded off the edge of the front wheel well.
The long and the short of it is this. There are 2 classes of car polishes. One is 'real' carnuba wax and the others are synthetic coatings like Nu Finish. The carnuba waxes look really great and shine better but they only last 2 or 3 weeks (according to McGuires) before they evaporate off the car. So if you're going to be waxing your truck every few weeks go that route.
The synthetic coatings can last up to a couple of months but they don't quite shine like the carnubas.
The paint companies say you don't need any wax at all.
Before you do any painting you have to remove all loose dirt and rust. Right before you paint, clean the surface with a clean lint free rag and a solvent usually called Prep-Sol. This will remove all residue, grease and wax. I picked up the Prep-All at an Auto Zone store.
I like the Eastwood Chassis Black to repaint parts under the truck. It is a thick high solids paint.
I use any kind if undercoating to spray the wheel wells. Just make sure you clean the surface well so you don't trap dirt, moisture and road salt under the coating.
I use the Rust-Oleum professional or industrial primer and paint to repaint my scratched rocker panels and brush guard. This also works well under the truck. There is nothing you can coat the rocker panels with that will protect them from an 8000 pound truck scraping against a rock. When I get back from off roading I just wipe the rockers down with prep-all, primer them and paint them and they look good as new.
Spraying your truck with Rhino Liner or Line X.
All the early Hummers from 97 and back were pretty loud. My 95 was so loud that I constantly got headaches. I did find ways to silence my trucks. During this discussion it was suggested that you strip the interior and spray the whole inside with Rhino Liner. I do remember some owners doing this. At the time AMG supposedly said that the plastic coating on the aluminum body parts could over time cause stress cracks in the aluminum. I don't know if that is absolutly true but one of AMG's areas of expertise is the use of bonded aluminum bodies.
I use the Rust-Oleum rusty metal primer and enamel paint to do my center hubs and parts under the truck. The center hubs are a rough casting so spray isn't necessary and the brushed on paint means you don't have to mask the area.
I've used 2 products to paint areas that are either already rusted pretty bad or areas that are prone to rust. On the Hummer the headlight mounting frames collect a ton of wet and rust up pretty bad. The undercarriage protection, the A arms and the battery tray are other candidates.
Rust Bullet and Por-15 are special formula paints that form a super hard coating and encapsulate the metal so it can never rust again. These paints harden in the presence of humidity.
I've used both and from what I see the Rust Bullet is tougher. Rust Bullet only comes in silver. Por-15 comes in a number of colors. I've tried the black, gray and white. The black Por-15 will turn milky if exposed to sun so it has to be over coated with another paint if you want it to look good.
Both paints are really hard. I've taken a hammer to them and they don't break off.
Unless you have a big panel to paint get the little cans. Once you open a can the paint has a reduced shelf life because as mentioned above they start to cure in the presence of humidity.
Another idea is to coat parts with Linux or Rhino liner which is really heavy duty.
This is my final secret spray. I actually picked it up at Sears as a little kit. Boeshield is a formulation invented by Boeing to spray aircraft parts so they wouldn't rust on the shelf. It forms a waxy coating that encapsulates the part. It can be removed easily with some solvent. You really don't have to ever remove depending on what you use it on.
I bought it to coat the spare parts I carry in my truck. Parts like half shafts, ball joints and bolts were getting rusted sitting in the back of my truck. I cleaned them off and sprayed them down. After a year they still look new.
The little bottle of rust free is a spray that removes surface rust from metal. Don't expect it to do a super job on heavily rusted metal. I'll wire brush the metal first and use the spray as a final wash.