Keeping your four-wheeled pride and joy looking spick and span is, well, a matter of pride and a thing of joy.
Like it or not, the more time you spend on the road, the more scratches, chips, dings, and other scars the road leaves on your car's paint. Even storing your vehicle outside will sooner or later let the sun take a swing at spoiling the beautiful shiny paint on your vehicle.
Taking your car or truck to the body shop for a repaint is time-consuming and pricy-the 500 dollars 3-hour paint job you see sold in cheese ads will leave your car looking worse than the chipped version you're looking at now.
While becoming a true-blue paint guy takes years of training, do-overs, and costly oopsies, with a bit of knowledge and a few basic tools and supplies, you can make the paint on your gas guzzler and neighbor waker-upper look, if not like new, then very close to it.
The Layers of Your Car's Paint
From top to bottom, your car's paint consists of the following:
The buffing compound is there to make the clear coat look nice and shiny and offer additional protection.
Clear-coat (multiple layers) is designed to separate the layers of paint on your car from the distractive nature around them.
Multiple layers of pigmented catalytic urethane paint( paint that hardens when combined with chemicals instead of drying as most do-it-yourself paints do. Those same poisonous hardener chemicals put catalytic paints out of reach of most of us working in home garages.
Stepping further down, you'll find primer, which is basically paint designed with superior adhesion qualities to hold on tight to the metal of your car and provide a grippy surface for the tinted paint layers sprayed on top.
Below the primer, you'll find a layer of rust treatment. And below the layer of rust treatment, you will find your car's bodywork, or if you are unlucky and someone skipped on rust treatment-rust.
Diagnose The Damage
Different types of damage call for different approaches to fixing them.
Before you start sanding, spraying, and applying your enthusiasm to other sorts of mayhem, it's important to clarify what you're trying to fix.
Clear Coat Scratches
Clear coat damage is shallow damage to the see-through layer that hasn't reached the layers of paint. Your vehicle will acquire it thanks to UV light exposure, water, a variety of unpleasant chemicals, and bird waste(which is surprisingly one of the most acidic and damaging concussions likely to come in contact with your car's paint).
Base Coat Scratches
Base coat scratches are a bigger issue—they go through the clear coat and damage the paint layers themselves. Small base coat scratches can be handled by touch-up paint pens; for anything larger, you're looking at spraying or brushing paint.
Deep scratches, or primer scratches, are damage going all the way through the clear coat, paint, and primer, reaching the metal below. This is the worst scenario; left alone, deep scratches will result in rust. And rust will spread away from the scratch itself, corroding the metal underneath the paint in the vicinity of the damage.
Tools and Materials
Working with paint is very much a time-sensitive process, leaving you no room to run out and get sanding paper or a touch-up brush. Before starting, gather up the following:
- Rubbing compound (rubbing alcohol)
- Sandpaper of various grits from 350 to 1500
- Rubber gloves,
- Tack rag to pick up dust or an air compressor
- Base coat paint
- Clear coat
- Touch-up pen.
- Electric buffer
- Buffing pads
- Buffing compound
- Automotive Wax
The key to a good-looking paint repair is finding the right tint of paint to match your vehicle. Red paint on a Ford is just different enough from red paint on Toyota to make it noticeable.
While matching up paint from your local big box tool store to your car's paint can come out looking pretty good, your best bet is either a car maker/model-specific touch-up pen or a jar of paint designed specifically for touch-ups on your vehicle.
On the inside of your driver's side door, you'll find a panel with the date of manufacture, model, and, most importantly, the vin number of your car or an actual color code.
With that number in hand, a dealership will tell you exactly the paint you need to match your car and sell you the paint you will need( at dealership prices, of course).
Catalytic paint relies on chemical interaction to harden and is not affected by the outside environment to the same degree as the paint we, DIYers trying to avoid exposure to dangerous chemicals, do.
Most paints will have a minimum temperature during which they can be applied listed on the container. If it does not, it's safe to assume that for the best results, you should stay above 50 degrees Fahrenheit.
The moisture content of the environment in which you're working affects the time paint needs to dry. The best environment to work in is between 40 and 50 percent relative humidity- a bit of moisture in the air is a good idea, as it prevents the paint from drying too fast and becoming brittle.
Prep is 90 percent of the painting's success. Yes, it sounds cheesy, but it's 90 percent true.
Start with washing the area you'll be working on with soap and warm water. Let it dry, or use a microfiber rag or compressed air to dry it.
Use a solvent to remove any traces of grease or wax. The idea is to produce a surface paint that can grab onto-a microscopic layer of oil produced by something as simple as a touch of a human hand will serve as a nonstick insulation layer between the paint and metal and ensure peeling paint and all your effort wasted.
If you're dealing with surface damage, like fading or sun damage affecting just the surface layer, the following steps will get your car back to its prime condition.
- Spray the damaged area with automotive clay oil (it helps clay bars slide over the surface without scratching the paint).
- Rub the area with an automotive clay bar to remove microscopic dirt and debris.
- Grab an electric buffer and wet buffer pad and buff the area using a buffing compound (about 1 tsp will do). Use overlapping strokes, continually moving the buffer. Or you can skip the electric buffer and apply some elbow grease.
- Repeat until the damaged area is back to its former glory.
- Apply a layer of car wax.
If the scratch you're dealing with is more severe, it is time to roll up your sleeves and start sanding. Remember-you're not trying to destroy clear-coat and paint surrounding the damage-restrict your efforts to the area directly around the chip or scratch you're trying to fix.
Using 1000 and up grit sandpaper to create a nice, flat surface for the paint to grab onto if the damage has not gone below the primer. If the scratch is all the way to the metal, sand down, making sure you've removed all rust-painted over rust will spread under the paint, producing bubbling and peeling of paint later on, resulting in a need for much more involved repair. A spray of rust arrester on the naked metal will give an extra layer of protection.
If the paint around the damaged area is loose and starting to flake off, remove the loose bits and sand the area they covered.
With sanding done, wash the area with soapy water and another round of degreaser.
Small Scratches or Chips
Scratches and chips that have gone into the paint layer but not through the primer and are less than a quarter inch in size can be touched up with a touch-up pen.
Make sure to use the pen that specifically matches the manufacturer color of your vehicle-even when the repair calls for a simple black color; there are dozens of options when it comes to automotive paints.
- Apply enough paint to come up a little proud above the surrounding, nondamaged surface. Move the paint pen from side to side as you're painting, and make sure not to apply too much, creating a drip.
- Give the fresh paint time to fully harden-most paints will require at least 24 hours, but err on the side of caution and give it more time if you're painting in colder or humid conditions.
- Test the paint by slightly scratching the surface with your nail.
- If the paint shrunk too much and is now below the surrounding surface-you can apply a second coat. If new paint is still sticking up, -a careful bit of wet sanding will bring it to level with the old paint.
- Once done leveling and sanding-apply a coat of automotive wax.
Medium Scratches and Chip
With damage more pronounced and reaching through the primer to the metal, fixing larger damage to your paint will involve a bit more effort and a few more steps.
Start with the surface prep, making sure that the area is sanding down to the metal, the flaky surrounding paint is gone, and no sign of rust in the area. Sand the paint edges around the damaged area to gradually slope to bare metal.
If the damage occurred long enough back for rust to develop, sand it out and apply a rust arrestor on the bare metal to ensure you won't have to redo the job in the future.
Brush or Spray?
With prep work out of the way, it's time to decide if you're planning on brushing the paint on or spraying the paint on with an air sprayer or a spray can.
The benefit of using a paintbrush is an easier learning curve and avoiding the need for masking the area around the scratch.
The downsides are a lower quality finish and having to apply the paint in fewer layers (the rule of thumb in painting is that the thinner layers you manage to achieve, the better looking the final result will be). A smaller area, especially if it's a scratch and not a chip, will benefit from a brush instead of a spray.
A spray can or spray gun connected to an air compressor will allow you to lay thinner, more professional layers. The downside is having to tape the area around the scratch, and the extra time waiting to let each layer dry will take out of your day.
If you're planning to use a spray method, it's time to tape around the damaged area to avoid putting primer and paint over an undamaged clear coat.
Apply automotive primer over bare metal or rust arrestor, brushing a thin layer with a fine hair brush if you've gone the brush road or spraying 2-3 thin layers with a spray gun or a spray can. Wait at least 10 minutes between each layer.
Test the primer with your nail to make sure it's fully dry. Wet sand it to create a flat surface if the chip you're working with is over 1/2 inch in size.
While the color of the primer doesn't matter much -the paint layer will be constantly on display. Test how well the touch-up color you've chosen matches your vehicle's paint on an out-of-the-way part of the car-door jam will do nicely to make sure you have a close match.
Try to stick to the same brand of primer, paint, and clear coat to avoid compatibility issues.
The application of paint with a brush is very similar to a primer. Layer at least two layers of paint, wet sanding gently in between, and allowing each layer to fully dry. Start with 1000-grit paper and finish the final layer with 1500-grit.
If you're using a spray gun, this is the time to lay as many thin layers as possible, drying and sanding with ever finer sandpaper in between.
Aim for at least three coats of thinly sprayed paint, with a final layer sanded down with 1500 grit to match the pain around it.
Allow the paint to dry fully.
Now that the paint is dry and sanded, make sure the area is flat (if you do so by rubbing your finger on it, like most everyone, apply a round of rubbing alcohol).
Paint or spray a couple of layers of clear coat, waiting for the previous layer to dry before laying a new one. You're looking to end up level with surrounding paint, but the more layers of clear coat you apply-the more protected your new repair will be.
Give the clear coat at least an hour to dry and apply rubbing compound.
In a week or so, grab an orbital buffer and a spoonful of wax and buff it over the entire area.