Paint and Body Chythar's 94 Cobra Clone Paint thread

[WhiteCobra95]

Amazing work! Nice job!

 

[Chythar]

It turned out to be a bit too hot during the heat wave, so I pushed my painting until late afternoon Friday. But paint I did. And made a mistake when mixing my paint, I think - so I'll have to sand the bumper smooth and repaint. Ah well.

Setup for paint went much like when I laid down primer. Put up the painting booth and wipe it down to remove dirt and paint dust. Wash & rinse the bumper, let it air dry then move it into the painting booth. Easy, but somewhat time-consuming. Oh, I took a picture of the stand I made to hold the rear bumper. The dowels sit in sharp curves or edges in the back side of the bumper, rather than somewhere else that might warp the polyurethane.

The next part was new - I had never used an HVLP gun before. First time for everything! I found a Youtube video on how to set up the HVLP gun for automotive paint, and the instructions worked well.


View: https://www.youtube.com/watch?v=pNfjSFyGYiM


I have an old Husky 32 gallon air compressor that I bought a LONG time ago to use with impact tools, and it worked great for the job. (Haven't used the air compressor since I got a good electric impact tool, tho) I put the HVLP gun together and added a water separator. The air compressor lets me control the output pressure, so I didn't need a separate one at the gun. Verified no air leaks in the gun, so I was set.

Time to mix up the paint. I bought Dimension paint from Sherwin-Williams, and it requires reducer and hardener in a 4:2:1 ratio. Easy enough to do if you have some mixing cups specifically for mixing paint. I bought a nice kit off Amazon that had everything I needed. Sherwin-Williams recommends three coats of paint if you're color sanding, which I will do - so three coats it is. I wasn't sure how much paint I needed for three coats, so I started with a 14oz batch (4:2:1 in ounces is 7, so I doubled it).

Not-So-Pro-Tip: wear a N95 mask when mixing the paint. Even with California low-VOC paint, this stuff smells nasty! And don't mix it in the house, or it'll take a long time to air out. You'd think I'd have learned that by now...

Paint booth ready? CHECK
Bumper washed and ready? CHECK
HVLP gun and air compressor ready? CHECK
Paint mixed? CHECK

We are ready for paint? CHECK

Did we make a critical mistake? CHECK

The paint I mixed was going on thinner than I expected. It beaded up, but was really thin between the beads. It's possible I added too much thinner. Also got what I think are fish eyes, the paint just wasn't sticking to the primer in those spots. Didn't look like I had enough paint for a second coat (and I needed 3), so I mixed up another 14oz batch. Mixed some of the new batch with the remnants of the old, and this time it went on thick and even! I have no idea what changed, but I was happy. Sadly, the damage was done in the first coat. There was paint left over after the third coat, so I sprayed some more paint over a few spots I missed. Dumped out the rest of the paint left in the HVLP's paint cup - it was still about 1/4 full. Next time, I'll mix up 21oz instead of 28oz (14oz x 2) for a full bumper.

Some advice if you're going to do your own automotive paint - buy the right gear. This isn't like using spray paint - you ABSOLUTELY need a rebreather, and should get a one-piece disposable coverall and some goggles too. Automotive paint that uses a reducer and a hardener is much like a 2-part epoxy, and you do NOT want to breathe that stuff in. An N95 mask is not good enough. I have a rebreather, but I didn't have the rest - I just wore old clothes and shoes. Afterward, I didn't see any paint on my arms but after wiping my skin with acetone I got a lot of black paint off. And my glasses were covered in paint too. I had to rub them down several times with acetone to clean them up. The gear is cheap enough, like $50-$60 on Amazon and you won't have to scrub a bunch of paint off when you're done. I'll be buying a suit and goggles before I paint again.

Another note - that paint is STICKY! That's a good thing I guess, but I wasn't expecting my feet to keep sticking to the plastic floor of the painting booth! Here's a photo from the next day, showing how much paint got all over the floor. And that's not dust that will wipe off, it's permanent.

Finally, cleanup time. I ran some acetone through the HPLV gun to clean it out as per its instructions, then took off the nozzle and paint can to clean them too.

Here's a photo of the bumper the next day, with the paint nearly cured. This spot has most of the fish eyes. The surface was very bumpy right after painting, but it did level out quite a bit. Now, it's all orange peel. The WHOLE bumper. It'll have to be sanded smooth before I paint again. Still, not horrible for my first time using a HVLP gun. The imperfections CAN be fixed.

 

[Chythar]

Sanding progresses. The process is the same as smoothing the primer coat: sand with 120/240/320/P600 grit. The Dimension paint I'm using recommends P600 as the final sanding grit to avoid fish eyes, so I use P600. I switch the direction of sanding when I go 'up' in grit, so: 120 horizontal; 240 vertical; 320 horizontal. I sanded P600 in swirls rather than a single direction. Since I was smoothing out orange peel, I needed to stop sanding as soon as the orange peel was gone. The top coat would be very thin at that point, and it would be easy to sand all the way through the top coat and into primer. Which I did in several places, but oh well. As usual, most of the work was done with 120 grit. Here's a pic of paint that's mostly sanded smooth. The black spots are low spots in the paint still.

As I mentioned before, I tape off edges on the bumper so I don't sand over them and round them off. This ends up taping off different 'panels' to sand at one time. I've finished sanding the panels I was working on, so it's time to tape off the other side of the edges and sand the remaining panels. I thought this was a nice contrast: orange peel versus smooth paint.

 

[Chythar]

Wow, it's been almost a month since I last posted? Let's fix that. Painting time! Same drill - set up and fixed the painting booth, brought the bumper outside then washed it and dragged it inside the painting booth. This time, I was super careful to mix the paint right. I also bought a set of painter's coveralls and some goggles to go with my rebreather. Shot paint and...

Orange peel again. It's not so bad this time, but I obviously didn't fix the problem. Le sigh. However, after checking the paint the next day the orange peel didn't seem to be so bad as last time. And no solvent pop, so that's good. I'm going to try polishing this one, and see how it goes. If I sand through the top coat, I only lose a bit of sanding time.

Best guess on the orange peel problem, is that I'm not getting enough air to my spray gun so the paint isn't atomizing right. I read online that there's some pressure loss from the tank to the spray gun, and the longer the hose the more you lose. I have a 30 foot hose bolted to the top of my compressor, so that's possible. Gonna buy an air regulator to put on the spray gun, make sure I'm getting the 30 PSI to the spray gun that it says it needs.

EDIT: Paint's already gotten thin in a few spots. Looks like a third repaint is in my near future.

 

[Chythar]

After some research and a lot of procrastination, I figured out why I was getting orange peel. I'll tell you what I learned, but I'm sure you're more interested in pictures. Try to ignore the ugly idiot holding the phone. Note the reflector indent on the right.

Not. Bad. But lost points for holding the phone vertical. Oh well.

Took these photos today, the day after painting. I'm sure I'll get better with more practice, but this paint is good enough to sand & polish.

Okay, let's rewind a bit. When we last left off way back in May, I had guessed that my orange peel issues were caused by not enough air pressure. Turns out I was right. I bought a pressure regulator and hooked everything up to see what the pressure drop was. You test the pressure on an HVLP paint gun when air is flowing through the gun. You do that by pulling the trigger halfway, which lets air flow without releasing paint. Of course, I'm testing so there's no paint in the gun; but I digress. So, I pull the trigger on the gun and the pressure read...2 PSI. When it should have been 30 PSI. That would be a problem! I cranked up the pressure regulator on the air tank until the regulator on the gun read 30 PSI, and the tank read 95 PSI. What? That's a lot of pressure loss. I was concerned that I wouldn't have enough air in the tank to spray a coat of paint, so I wanted to bring that number down. Some experimentation later, and the main problem was the cheap water separator I was using. Bought another one that claimed "high flow" and the tank read 65 PSI. Much better!

One of my tests was to remove the water separator and hook the gun (with the pressure regulator) directly to the tank - no hose. This is obviously useless for painting, but it should eliminate any and all pressure losses. I was able to drop the pressure from the tank down to 50 PSI when the gun showed 30 PSI. How do I have a 20 PSI loss between the tank and gun, with nothing but a coupler in between? I don't get that.

Alright, air pressure problem fixed; time to find a good day to paint. It's been really humid here on SoCal lately, around 80-90%, which is really unusual. And way to high to paint, even with a water separator. But the weather report showed the humidity was going to drop to 40% yesterday and today, then jump back up to the 80's. So I took that small window to paint the bumper. You saw the result above. I still need more practice, but I am getting better.

Had a weird problem with the paint gun after spraying the second coat. Paint started dribbling out the nozzle, and it wouldn't stop. Didn't dribble when spraying, fortunately; but still got a few drops on the paint. That's no worry, I can carefully sand those out. After I was done, I noticed that paint had drained backwards through the gun and into my new water separator, destroying it. Sigh. At least it wasn't too expensive. I have been cleaning the gun after each paint attempt, but clearly not good enough. I'm guessing the gun needs to be taken apart and cleaned better.

And that's the State of the Bumper. Next up: sanding and polishing.

 

[Chythar]

Well. Here we are, nearly six months since my last post. Feels like it was much longer.

TL;DR - Bumper is COMPLETE and installed on my 94 Cobra clone.

This project has been really overwhelming. When we last left off, I had decided to sand and polish the bumper despite getting orange peel again. It was a lot more work than I expected. I'd get tired or frustrated after sanding for less than an hour, then not look at the bumper for at least a week. After sanding the paint level, I got some momentum and made better progress. It was a lot of sanding, but if you want a mirror finish ya gotta put in the time. Don't forget to use painter's tape to protect your edges. I used 3M 06525 Precision Masking tape. My sanding process is:

1. 800 grit, horizontally across the surface. Stop when the paint is almost 'level'; you should still see some different-colored spots that haven't yet been sanded.
2. 800 grit, vertically - 90* across the last direction you sanded. Sand until the paint is level and a uniform color, and all the horizontal scratches are gone.
3. 1000 grit, horizontal - until the 800 grit vertical scratches are gone.
4. 1000 grit, vertical - until the 1000 grit horizontal scratches are gone.
5. 1200 grit, horizontal - until the 1000 grit vertical scratches are gone.
6. 1500 grit, vertical - until the 1200 grit horizontal scratches are gone.
7. 2000 grit, horizontal - until the 1500 grit vertical scratches are gone.
8. 3000 grit, use small/medium swirls. Sand until all horizontal and vertical scratches are gone.

You can shine a light across the sanded paint to see any scratches in the surface.

That's a lot of sanding! But again, the smoother the paint the more reflective it will be in the end. During a break from sanding, I decided to paint up a few parts. The seller I bought the Cobra bumper from had removed the metal side brackets, so I bought a set off of eBay. I decided to paint them red. Why bother, since no one will see them? Because I will know they're there. I also painted the gray plastic behind the rear reflectors black. On my original bumper, I could barely see the gray plastic behind the reflectors - so I wanted that gone. No need to polish those parts, so I just used some rattle can paint I had. The red is actually some leftover VHT caliper paint.

With the sanding done, it was time to polish the bumper and get it all shiny. I was originally going to use a power drill with a polishing pad to polish the paint, but decided to just do it by hand with the same polishing pads. Didn't take much longer than using the power drill, and I had better control of the process. I moved the polishing pad in small swirls across the paint, and I overlapped the swirls about 50% as I went along. I'm using Meguiar's polish products, and some generic polishing pads from Amazon.

1. Start with Meguiar's M105 polish with a coarse pad. One pass across the paint, but overlap the swirls as mentioned earlier. Wipe off polish when dry.
2. Next is Meguiar's M0216 (Mirror Glaze 2) with a medium pad, until all visible scratches are gone. This took me two applications of polish. The reflections in the paint will still be kinda fuzzy, though. Wipe off each application of polish when dry.
3. Final pass is Meguiar's M0316 (Mirror Glaze 3) with a fine pad. I did two applications of this polish. Wipe off each application of polish when dry.

This first photo is from the first Meguiar's M105 polish pass. The transition between polished and non-polished paint is really noticeable.

This next one is after two applications of Meguiar's M0216 (Mirror Glaze 2). Paint is reflective, but not sharp and clear.

After the final polish, it was time to remove the old bumper and install the new one. The old one came off easy, but the new one was really tight. I could get one side on, but I couldn't stretch the other side far enough - it was always a little bit short. Maybe I was supposed to leave the bumper in the sun to let it soften? It was night and cool out, so no luck there. But eventually, I got the bolts to line up and got the sucker installed.

Looks like the paint needs to be polished better, hand polishing doesn't seem to be enough. But it looks to be a good foundation.

As a reminder, the "COBRA" lettering is the original red paint that was on the bumper. I had masked off the letters, and hoped they would polish up nicely - which they did. It would have been much easier to just paint over them then paint the letters again in red, or just use a set of decals. But I like the idea that the red is the original paint, and not just something slapped on over the top.

And that's the end of the rear bumper project. I'm not done, of course - I still have to paint the rest of the car. But it will be a couple of months or so before I start on the next part, which will be the front bumper. For now, time to enjoy a job well done.

I realized a while ago that the rear bumper on the 94-98 cars is the most complicated part to paint. There's a lot of curves and grooves to watch out for, and ya gotta paint and polish them all. In hindsight, it would have been easier to learn on a less complicated body panel. But learning on a part that wasn't already on the car had its advantages; I could take as much time that I needed, and I sure needed a lot of time. It's been 16 months since I got the Cobra bumper and started sanding it. Hopefully, things will get easier from here on out.

 

[Chythar]

Short update. Decided to try polishing the bumper's paint with a power tool, which is just a power drill on 'low', and the polishing pads. The results are below. I wouldn't call this 'show quality', as there are some minor imperfections I'm not going to show you, but it's pretty darn close.

 

[hoopty5.0]

Awesome! Kudos for giving it a go. I often think about it but cant commit

 

[Chythar]

Awesome! Kudos for giving it a go. I often think about it but cant commit

I was like that for many years. I wanted to do it right, but there was too much to learn. It paralyzed me for way too long. But I ended up learning most of what I needed to know through other projects. You can practice laying down paint and polishing it with cheap rattle-can paint, no need to practice with the expensive stuff. That helped me a lot. Just realize you'll have to paint over your practice areas with better paint in the future, as the cheap paints will fade within a year or so.

A lot of the work is shaping the paint and primer. You have to have a feel of the shapes in the parts you're painting, and how to sand them to keep those shapes. I learned that when fixing the driver's rear quarter panel on the Cobra. Once I finished that project, I realized I knew a good chunk of what I needed in order to paint the car.

There have been so many times I wanted to quit. You could say I did quit several times, when I let the project sit for days or weeks. Many times I only came back out of guilt. I had invested so much time into the project, I would feel worse if I abandoned it. Sometimes, success is persistence and stubbornness.

If I'd give any advice to anyone, it would be this: If I can learn to paint a car part that well, so can anyone. I am not a professional body or paint guy. I won't be one when I finally finish the car, and I don't intend to ever do this for a living. I haven't taken any classes or had anyone teach me directly, just what I can find on the internet and some advice from @95steedamustang. Most of the tips and tricks I've learned were from screwing something up pretty bad, and learning how NOT to do that again. But again, anyone can learn how to do a professional-level paint job. It will just take time and practice.

When a project gets overwhelming, I try and break the work into smaller pieces. Break those down into smaller pieces, until you get a small enough piece that you know how to do. Sometimes, that small piece is "research XXXX on Google." Sometimes, you won't really know how to do a piece until you try it. Even if you mess up, the practice can help you understand what you have to do better next time.

 

[Chythar]

It's been a while. Went through a forced move where I had to throw out a lot of stuff and reestablish myself. I expected things to suck for a while, but they haven't actually. I'm working for a Ford dealership now, so I'm surrounded by car guys, and I live closer to my good friends who are also into cars (but not Mustangs). So overall, I'm in a better place. Enough of that, you're here to read about painting!

This summer's been too hot & humid to paint, with humidity over 70% most of the time. The general rule of thumb that I've read is to paint with temperatures over 70* and humidity below 50%. Too low of a temp and/or too high of humidity can cause issues with the paint curing properly. At least, that's what I've read and I don't know enough to know what the exceptions are. So, no painting all summer. But the first weekend in October, I checked the weather report and saw a weekend with humidity in the 40's! W00t! Time to get the painting project off the back burner and paint my front bumper.

I had to trash my old painting booth, but it's easily rebuilt. There's a concrete patch in the back yard of the place I'm living in now, which is a perfect place for a new painting booth. I limited my last booth to 8ft x 8ft because I only have my 'Stang to transport parts in, and I can only fit 8ft long boards and still close the trunk. Like so:

But an 8x8 booth is too small for a bumper, so I screwed two boards together and extended the booth to 8x12. Here's a photo of the frame already built with some of the plastic stapled up.

I had already sanded most of the front bumper over a year ago, so I just had to finish up sanding everything with 320 grit. Sprayed down a coat of adhesion promoter, then a few coats of SEM flexible primer. The extra room made it really easy to maneuver around the bumper. All done and cured. I built the bumper stand high enough so I could easily spray the ends of the bumper.

I let the primer cure for a week, and fortunately the next weekend also had low humidity. So, time to paint the top coat. Last time I painted, the paint gun started dripping paint out of the nozzle when not in use. This time, I disassembled the gun entirely and soaked the parts in acetone for several days. I had flakes of paint floating in the acetone within a few hours. I cleaned the gun out, then reassembled it. A test with water in the gun did not reveal any leaks, so I'm guessing the dribbles were caused by me not cleaning the gun properly. Oops. As for the orange peel I was getting, an online article suggested that the paint wasn't atomizing properly. So I bumped the air into the gun up 2psi to 32. After painting four coats, the orange peel seems to be mostly gone. But I laid down WAY too much paint, and got several runs. Those will take a while to sand out.

I'm going to let the paint cure through the winter, then work on sanding & polishing the bumper in the spring sometime. Unfortunately, my new neighbors decided they didn't like the sound of my air compressor, so my landlord said no more painting around the house. Boo! Will have to find a new place to set up my paint booth, or find someplace that rents booths or something.

 

[AeroCoupe]

Can you run the compressor in the house?

 

[bird_dog0347]

Can you run the compressor in the house?

Or the garage? Maybe just talk to the neighbor and ask if there's a time that they won't mind you doing it as it won't be a regular thing?

 

[85GTStangGuy]

Unfortunately, my new neighbors decided they didn't like the sound of my air compressor, so my landlord said no more painting around the house. Boo! Will have to find a new place to set up my paint booth, or find someplace that rents booths or something.

Or maybe make a "dog house-type enclosure" with sound absorbing material inside.... enough to muffle the sound to an acceptable/not noticeable level.