Auto body paint | 350Z front bumper

For my second attempt at painting auto parts I took photos with my camera to get higher quality documentation. For this project I would be repairing and painting a black 350z bumper to championship white NH-0. I chose this color because it’s the color I plan on painting my 1999 Acura Integra sedan once I get the type R front and rear for it. I did this in my garage without any plastic sheeting, I wanted to see how bad the overspray would be.

This left table held most of the items I would be using, including 2 Harbor Freight HVLP guns, paint, reducer, clear coat, hardener, primer and body filler.

This is the paint, primer and body filler that I used.

The condition of the bumper was really poor and turned out to be more work than I expected, but it gave me a chance to test of some different methods of repair. This thing was loaded with stress cracks, chips, dents, torn mounts and etc.

One of the first steps was to wash the bumper and remove all the pieces that I did not want to be painted. This reminds me of when I asked MAACO to NOT paint certain things on my 240sx and they did anyways. Everything came off easy, even the emblem which just needed some heat and a little pulling pressure.

After the pieces were removed I looked over the bumper and made a small game plan on how I was going to take care of all the damage.

I figured I would sand all the damage spots with 220 grit and go from there. That sanding step took out a decent amount of chips and scratches.

This mounting tab was split and held together with zipties. I used bumper epoxy and mesh to repair it. This repair ended up working really well but was not pretty.

Here’s were the disaster began, with the body filler. I took some filler out of the can, put it on the mixing board and added a bead of the hardener. By the time I started to apply the filler to the bumper it was already hard! So I applied what I could then mixed up another batch with less hardener. Same thing happened! I used what I could and pretty much gave up. Later on after watching some youtube I realized I should have used a lower grit sandpaper for the body filler zones.

Here is everything filled up, some spots I didn’t apply filler to so I could see how it turned out.

It appears I didn’t get a photo of the body filler after sanding, but some spots I didn’t get 100% flat to see if it would show after base and clear. Turns out it did lol, noted.

Disaster pt. 2

Before getting the primer ready I cleaned the gun, I haven’t drilled out the tip yet for primer but I wanted to see how the 1.4mm handled the thick primer. After getting everything cleaned I reassembled the gun but forgot to put the fluid adjustment needle spring back in. But of course I didn’t realize this until it was time to fill the cup.

To clean all gun parts I use a general solvent.

While setting the gun up I broke the regulator so I took a trip to harbor freight to get another one and I saw they have an updated version that uses more metal. I also got the slightly more expensive air filter that has a metal insert for the top. Using plastic threads are so annoying.

After getting the gun setup I opened the primer to mix it up and noticed how crazily separated the contents of the can were, was super difficult to mix, nearly impossible without spilling. I added the hardener or whatever then began to stir with the stick. It was super clumpy but I still poured it into the cup. As I was pouring the primer into the cup, the primer started to drip out of the tip on the gun!!! I didn’t realize what was going on and primer was spilling everywhere. After the cup totally spilled through the gun I took the other gun apart to see what I missed. The fluid needle spring! Which I even threw away thinking it was a part of the broken regulator. I got the second gun ready to go and didn’t have any paint spill through. I went to test the spray and fan on cardboard but didn’t have the cup lid on and forgot. I pivoted and stood up after test spraying and SPLAT, spilled painted on the floor and on the cover I had on my subaru engine. FAIL, but luckily the engine was covered. When I finally got to spraying the primer, it gelled up very quick to the point where it was unusable, I was able to cover the bumper right before this happened.

After that mess I got the gun cleaned up and ready to spray the base coat, I used about 3 coats.

These photos came out cool, the sun rays coming through the garage door window illuminating the floating overspray.

Here are some of my notes, I take notes that way I can reflect on what I did right and wrong so I can improve with each job I do.

I let the base coat flash off and rest for about 30 minutes then got the clear coat mixed up. After doing some youtube research I learned how wrong I was applying the clear coat. I should be only doing 2 coats while keeping a wet edge and about 50% overlap. I was just shooting from the hip the entire time with no real technique.

Bumper was looking fairly glossy but with heavy orange peel from me not laying it down heavy enough.

I let it sit out in the sun the next day and evaluated my work. The body filler spots where I sanded down the right amount came out pretty decent but the places where I did not sand enough came out with a hard noticeable edge. I definitely need a lot more practice using body filler. The paint aspect came out pretty decent but I should have sanded the bumper after primer to give the base and clear coats a smoother surface to adhere to. Knowing these mistakes I can improve on my next project. I have many friends wanting me to paint various items and whole cars for them so I am trying to get as much practice as possible so I can provide the best service. I picked up an integra hood and front fenders to practice on.

Thank you for reading!

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