Auto Body Repair!
Auto body repair has been a staple in the automotive industry for quite some time. Usually known for being highly expensive, many people around the world have a difficult time being able to afford repair costs for cosmetic damage.
Luckily after today you will understand what auto body repair is and how you can perform it right in your own driveway.
Auto body repair is a specific skill set that allows someone to repair physical cosmetic damage to vehicles. Typically speaking, auto body repair can be broken down into many smaller categories. Scratches, dents, cracks, etc… are all great examples of cosmetic damage.
Getting started isn’t a simple task. Fixing your auto body damages can be very expensive and very time consuming. Auto body repair is usually very expensive but as always it depends on the damage.
We are going to walk you through some brief steps today and outline the basics so you too can get started repairing your own vehicles. The biggest piece of advice we can give you is to be patient, take your time, and don’t panic about your mistakes.
If you make a mistake it’s always fixable no matter how big of a mistake you make. It’s going to happen and all you can do is learn from them. Learning auto body is a completely different world compared to mechanical repairs.
In some ways it’s easier and in some ways it is far more difficult.
The main steps of auto body repair are the following:
- Examine The Damage
- Remove Dents/Scratches
- Fill/Patch Weld
- Smooth The Area
- Painting The Surface
- Blending The Repair
With out steps now successfully listed, it’s time to go into more detail.
Examine The Damage!
You’ve been hit in your vehicle, hit something, or overall just had something happen to your car. The first step is to examine the damage done. It’s super important to collect as much information as possible first. This will help you get the tools/supplies you need.
Additionally this is going to help you determine roughly how much time you may need.
Understanding the entire process is only going to help you complete the job easier. Auto body isn’t a task that is simple to perform. You really have to take your time and do each step carefully to achieve a brand new look.
This can be time consuming but we promise the rewards are totally worth it.
Any cracks, dents, scratches, or any other cosmetic damage need to be removed first. You can start with the easiest repair first which is scratches. There are basically 2 different types, surface and deep scratches.
A surface scratch means only the top clear coat received damage.
To make that easier to understand, you typically have 3 layers of paint. Primer, color, and clear coat layers. A surface scratch is when something small typically rubs against the vehicle and scratches the paint.
A clear coat scratch typically looks like a white line and isn’t very deep.
On the other hand a deep scratch is a scratch that has gone through the clear coat down to the color or primer layer. These are significantly harder to fix, but we will walk you through it!
To remove a surface scratch you are going to need 3 different grits of wet sand paper. 1000, 1500, and 2000/2500 wet sandpaper will be used here.
For best results, soak your sandpaper for about 15 minutes before the repair.
This will prep your sand paper making it glide much easier. Additionally this will reduce your changes of accidentally putting worse scratches in.
We know sanding down the top layer sounds crazy, but it’s what you have to do. The reason we are using 1000 grit to start is because it’s so fine it will only remove the top layer. On top of that the scratches will be much smaller/fine making them easier to remove.
Wet the area you are working on thoroughly with water. After the surface is wet grab the soaking piece of 1000 grit wet sandpaper and begin sanding.
Make sure you are always using a sanding block. The only time to not use one is on odd edges.
A sanding block will keep sanding movements consistent and the same level. This helps achieve perfect mirror like results at the end of the repair. If you are working on a small repair area use a smaller sanding block.
If you are working on a bigger area such as a hood, using a larger sanding block helps significantly. Sand from left to right and up and down movements. Never move your sandpaper in a circle when using a sanding block.
The entire goal here is to remove just the top layer of scratches in the clear coat. Start with your 1000 and then work your way up to 1500 then 2000/2500. The end result should be a flat/dull looking surface. The scratch at this point will be gone and then all you have to do is buff the area (more on that below).
If you have a pretty massive dent in the surface you are working on, this section will cover that. This section will also apply to very deep scratches that have gone through the clear.
For dent removal you have tons of different options. However being that this is a DIY site, we are going to give you a couple of cost effective options.
Option 1 is to pull the dent with a cheap dent puller. If you can get to the backside of the surface you are working on. Take a non metal hammer and try to gently tap and pull the dent out of the surface.
The next option is to use a drill and dent puller. These are around $10 or so at a local auto parts start. To remove a dent with one you simple drill a slightly smaller hole than the bit on the dent puller.
You will have a small hole now that you can thread the end of the dent puller to. Thread in your puller and start slamming the slide hammer towards you to remove the dent.
The final option is to use a stud welder for auto body. This is more of a commercial tool but works great for DIY enthusiast as well. This tool works pretty much the same as a dent puller, this time there is no need to drill though.
If you are using a stud welder, sand the surface down to metal, press the stud welder against it and pull the trigger. As you hear it click and see it perform a weld, lift the gun off and all that will be left is a stud.
Using a pair of grips, a body hammer, or any other tool, pull on the stud until the dent comes out.
For any additional small dents and dings that you cannot get out, you may need to use body filler. More on body filler below!
Auto Body Repair – Deep Scratches.
Sometimes you have it where a scratch goes too deep and hits metal or the primer/paint coats. To fix these you will need to sand the area down till the scratch is gone and the area is flat. Start at a 400 grit and work all the way up to 1000 following the steps you did previously.
It’s the same process as wet sanding with the 1000+ grit but instead of sanding to the surface, you are sanding down to paint/primer/metal.
The scratch should lift out and you can verify this by rubbing your fingers across the surface. If the surface is smooth and you feel nothing, the scratch is out and you can move onto your primer coat.
However sometimes we have a dent/scratch that is just so fine it wont come out. This is where we need to introduce body filler. Body filler gets hard as a rock and can be sanded. Make sure you get a filler that works with your application. Fiberglass filler for fiberglass, plastic patches for plastic, and Bondo or any other body filler that you wish to work with on metal.
Most of the fillers are going to come with the filler and a hardener. Most of the time you will use a dime or nickel sized glob of hardener. The mixture will be different depending on how fast you want it to dry and depending on how much filler you will use.
Using a straight edge or body filler applicator. Mix the 2 ingredients together NEVER stirring it. You kind of want to flip it and swirl it instead to remove any air pockets out. Once it’s mixed apply it to the applicator and lightly spread it.
As you spread the filler onto the panel press down a little harder toward the end to feather it out for sanding purposes. Once it hardens and cures, go ahead and start sanding with 400+ grit paper and work your way on up to about 800-1000 grit again.
You should have nothing but a smooth surface by now and your scratches/dents should be done! You are officially through the word parts of auto body repair and now is a great time to take a break!
Filling/Patch Welding Auto Body Repair!
Surface scratches and dents/deep scratches out of the way, now we move onto more interesting scenarios. What happens if you have a rust hole or if the vehicle has been in an accident? We will touch base now on what to do from there.
Instead of paying thousands to get it fixed we can fix it right here at home here’s how.
If you take a 1/4 panel as an example that gets dented in to the point where you cannot fix it, you have 2 options. Either A you can order a replacement 1/4 panel and weld a whole new one on. Or B, you can cut out the bad section and find a used part to fix it.
Option A is much harder and should only be attempted by professionals only, option B however isn’t so bad.
Many states have “salvage yards” or “junk yards” nearby. Parts are typically insanely cheap because you are pulling them yourself. Instead of cutting out the entire panel you are working on, we are going to find the same vehicle and just cut the section that you need out.
Have your new section ready, line it up with your car, measure and simply cut as close as you can to your new piece. From here, you are lining your new piece up, take a piece of paper with a medium strength magnet to hold it in place. Once it’s in place go all the way around the panel leaving 1 drop of welding wire around the panel.
Once it’s tacked in, remove your magnets/paper (we use paper so the magnets don’t scratch the metal) and then finish welding all the way around your panel. It should now be welded in place so all that’s left now is the same steps we took before.
Using a wire brush/sandpaper, flatten your weld spots down so they are flush and then fill in your scratches with filler or spot putty. Once applied allow it to cure/harden and then sand smooth then paint! Not too bad!
Smooth The Area!
Auto body repair is all about sanding and keeping things smooth.
A good typical rule of thumb to follow is if you can feel it, you can see it.
This statement alone will help you so much. If you run your hand across the surface and you feel any bubbling or any lines, then something is wrong. This means a spot on the surface you are working on is either higher or lower than the rest.
You will need to get the entire surface on the same level so you don’t see anything that you have done.
Start Low, Work Up.
Just like before you will start at a lower grit and work your way on up. If you just laid body filler/welded in a new piece, start around the 300-400 mark and increase in increments of 100-200. As a example, if we started at 400, we will sand, clean, and then sand again with 600 grit.
Keep doing this all the way up to around the 800/1000 grit mark to remove any blemishes or scratches you left.
Once you have hit the surface with a 800/1000 grit, clean it off really well and then rub your hand across it to see if there is any high or low spots. If there isn’t you may continue, if there is, get back to sanding until it’s smooth!
There is a huge dispute in the auto industry, that dispute is whether or not you can have a good looking car from a rattle can. You can, but obviously it is much better to get adjusted/used to a HVLP (high volume, low pressure) gun.
This will make laying paint like glass once you get it dialed in correctly, for the sake of this DIY project though, we’re going to assume you only have access to spray cans.
You will undeniably get better results from a compressor/paint gun, but you can get GREAT results with a rattle can if done correctly.
DO NOT USE cheap spray paint, you are going to want quality paint packed into a can for the best results. Many places such as Automotive Touch Up or Kenowa offer exact match original equipment paint in a spray can.
Both are great options and just a couple out of the 100’s that are available for you to utilize.
The painting step is actually super simple. It’s all about distance and being consistent which are all traits we naturally have.
Nice tip: Put your spray paint can in a bowl of warm/hot water to soften the paint in the can. This will help with orange peel and allow the can to spray more even.
Unlike a paint gun, spray cans cannot be adjusted and therefore you are pretty much stuck with what you get. Because of the way spray cans are, the above tip can be a life saver.
Simple Even Coats!
Start by applying a “tack” coat. Hold your can 7-10 inches away roughly and lightly spray the surface you are working on. The goal here is to just get the surface a little wet without laying too primer on. Your “tack” coat should only have basic coverage and you should still see other colors/materials.
Once it dries, follow back through with another coat and now you should have close to full coverage. Repeat this process one or two more times until you have full coverage.
After you have waited some time for the primer to dry, go ahead and sand it with a 1500 grit piece of paper. This will make sure the entire primer coat is smooth and ready for color. Once you have your primer layer smoothed down, move onto color.
Color is typically the easiest coat, following the same steps as before, start with a tack coat. After your tack coat dries, spray 2-3 more coats on until full coverage is achieved and let dry.
Once you color coat has dried, clean the surface down again and get ready to lay down some clear coat.
Clear coat will be the same exact process as color and primer but with 1 extra added step. Wet sanding and blending!
The auto body repair project is near completion and you’re doing a great job! The final step is actually pretty simple, blending and final touch ups.
When we say blending we don’t mean blending your paint, that’s a subject for another time once you get more advanced!
What we do mean though is making sure the whole car looks like new.
If you happened to get any orange peel in your clear coat runs, follow the steps above for removing surface scratches but do the whole surface instead. Work your way on up to a dull even haze. Once you have the dull looking surface, we now know it’s even and needs to be polished.
The first step is to compound the entire car. Make sure the ENTIRE car is clean and then begin applying your rubbing compound. Rubbing compound is going to be a paste that you buff by hand or via electrical orbital buffer or dual action polisher.
There is a ton of information about this in our car restoration post so be sure to check that out as well.
Anyways, for best results obviously buff with a dual action polisher but today it’s going to be done by hand. Apply some compound to your microfiber towel and remember the saying “wax on, wax off”? You’re doing the same thing here.
Apply a couple of small drops and buff it in using tons of elbow grease and leverage. This should lift scratches and swirls out leaving a wet looking surface instead of a dull one. From here repeat the same exact process but with polisher and seal wax to protect the paint coat.
From here everything should looks shiny, even, and the best part is, it will look like brand new!