DIY: Getting a mirror finish using spray paint

[cianuro]

I was tired of the chrome trim in the trunk door of my ’08 WRX, so I decided to paint it to match the car as close as possible. My local auto paint shop asked me for $35+ for a spray paint can with the color code of my car. This didn’t include the clear coat. So, since I’ve painted plastic trims before, I decided to do it on my own.

I had some leftover clear coat from previous parts I had painted, so all I needed was the closest matching color I could find to make it work. I used Platinum Silver from DupliColor which I found to be the closest. I also tried plain Silver, but it was a bit darker.

So, the point of this thread is showing what I did using spray paint to get that reflective finish the factory paint has. Now, we all know that spray paint tends to leave a porous surface finish. I’ll explain how to get the reflective finish without the need of paying a professional.

First of all, what you’ll need:
1- Spray Primer
2- Spray Paint (your color of choice)
3- Clear Spray Paint
4- Microfiber towels
5- Polishing Compound (not Rubbing compound, I used Turtle Wax brand)
6- 3M Hand Glaze
7- 2000 Grit Sandpaper
8- Microfine Sanding Pads (look at the pics)
9- About 3 days (depending on weather conditions)
10- A whole lot of PATIENCE…



Sorry, I threw away the primer before I took the pic.

Here are the steps:

1- Take the part you want to paint, clean it well. Try to use those nurse gloves or something similar so that you don’t get finger grease on the part. If the part is a bit porous, sand it a little with the 2000 grit, always using water to keep it wet while sanding it. This will elongate the life of the sanding paper.

2- After you’ve cleaned the part completely, make sure it is as dry as possible. Now, you can apply the primer. In my case, I used Engine Enamel Primer because it holds on to plastic pretty well. The coats will depend on you, but I recommend 3 or more. Let the primer sit for 3 to 4 hours.



3- Once the primer is dry, go ahead and apply the color coat you’re going for. As for coats, I gave mine 7 thin coats of the color. If you apply several thin coats, you’ll get a smooth enough finish without the risk of runs or sags on the paint. Now, let that color sit for about 24 hours. I know it is a bit too much, but at least you’ll make sure the coats are cured and ready for the next step.



4- Grab that 2000 grit sandpaper and softly sand the color using water. Don’t apply pressure to sandpaper, just glide it through the part as you hear it scraping the coat. Rmember, we just want to smooth out the color, not remove it. Keep the part wet. You’ll notice that as you continue sanding, the water sticks to the part. This is what you want. Dry it a bit and look at the part under some lighting. You’ll see that it kind of looks like a grain finish. This means that you’ve removed most of the roughness of the part and as you slide your hand across the part, it’ll feel smooth.



5- Dry the part completely. Make sure it is clean and that there is no sanding residue on its surface. Now, you can start applying the clear top coat. Same as the color, I gave it 7 thin coats. You’ll notice that the clear coat will start showing some whitish spots throughout the part. Don’t worry. This is how the clear coats on spray behave. It just means some parts are more wet than others. After you’re done with your coats, let the clear sit for 24 hours. As the day goes by, you’ll notice that the white spots start to fade during the cure process.



And here it is after fully drying:



6- Now it’s time for using the Microfine sanding pad. Grab the sanding pad and start sanding the clear coat the same way the color was sanded. Yes, you need to sand it to get a smooth finish. Same as the color, you’ll use water, and you’ll see the same behavior of water sticking to it. Make sure you get the whole part smoothed out. You’ll see a white foam build up while doing this. Just keep the part wet and keep sanding until the whole part feels smooth. Remember, don’t apply pressure. You just need to smooth the coat out, not remove it.

7- Starting with a small corner, use a microfiber towel to polish the part. Use a different microfiber towel to wipe any excess. Now, take a look at the corner you just polished. If it looks a bit grainy, then you need to use the sanding pad a bit more to get it as smooth as possible, without damaging the clear coat. If it’s a mirror like finish, then you’re good to go with the whole part.



Notice that the right side reflects better than the left. I've polished only half of the part so that you can see the difference.

8- Once you finish polishing the part, use the hand glaze to seal it. Apply it the same way you were applying the polishing compound. The polishing compound will leave the clear coat bare, so this is a necessary step to protect it.

9- All that’s left is installing the part where it goes. Here's my finished product:




I would recommend that you practice this process before doing it where you want it. I had some small dash trims spare from my previous car, so I used these to check on colors and check which one looked better.

As for weather conditions, if you don’t have a well ventilated area with no humidity and good temperature for painting, don’t try this. Spray paint behaves awful under humid conditions. It’ll start to peel off, or graining during the paint process.

As per the can instructions, I gave each coat 10 minutes. This is enough time for the paint to get tacky, but not dry, allowing the other coats to blend in while you apply them.

The clear coat I used stays a bit yellowish on top of the silver during the cure process. Since I practiced on some parts before using what I wanted to paint, I noticed the yellowish look fading off as the days went by. I hope the same happens when I look at my part a week from now.

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[ADAS1223]

that looks really nice. gj

[Amnizu]

Process is really good, great work here. Only comment I have is you can see a color difference between the factory paint and the painted trim piece. I imagine that this would happen even if you were to have used the $35 dollar exact paint match from the paint shop due to the adjacent panels not being blended.

I am interested in doing a similar process but to a flat black finish on this trim piece. Something to match the color of the rear diffuser, other than using a flat black paint (obvious), how would you change the process? I am assuming I would still want to put a clear coat over this.

[JLAG]

Wow nice write up. this is going to help in painting in general.

[cianuro]

Originally Posted by Amnizu

Process is really good, great work here. Only comment I have is you can see a color difference between the factory paint and the painted trim piece. I imagine that this would happen even if you were to have used the $35 dollar exact paint match from the paint shop due to the adjacent panels not being blended.

I am interested in doing a similar process but to a flat black finish on this trim piece. Something to match the color of the rear diffuser, other than using a flat black paint (obvious), how would you change the process? I am assuming I would still want to put a clear coat over this.

About blending, I know it's not an exact match. I practiced with some parts before actually doing this and noticed that the clear sets in about a week or two. I did this on a white part before and got the same results. It was a bit yellowish when I finished it, but after a couple of weeks of exposing it to the weather, the yellowish tone faded away. That's why I said at the end that I hope that this part behaves the same.

As for your flat black idea, I think that what you'll need is a "Satin Clear Coat" over the flat black. I've used flat black alone on inside trims and it behaves pretty good. I don't know how it'll behave when exposed to rain. I know I've seen satin clear coats in spray, but I don't remember a brand or a place because it is a bit uncommon.

I believe the process would be the same, except sanding and polishing the satin clear. If you do find it, practice on a plastic part (straight enough surface) so that you can have an idea of what the end product will be.

[NitroTrike]

Did you also wet sand the primer, or did I miss that somewhere?

[NCORWRX]

Originally Posted by Amnizu

I am interested in doing a similar process but to a flat black finish on this trim piece. Something to match the color of the rear diffuser.

For a closer match to the diffuser I would think a satin black would work best. imo.

OP, looks great!

[cianuro]

Originally Posted by NitroTrike

Did you also wet sand the primer, or did I miss that somewhere?

I've sanded the primer on previous ocassions, but I've found that the color coat sticks better if you leave the primer unsanded. Sanding the primer will leave a really smooth finish on the color coat, and it'll be close to the mirror finish you want. I don't do it as much because I pay more attention to the color and clear coat finishes.

In conclusion, it's up to you. I managed to get the mirror finish I wanted without sanding the primer, so the decision's yours to make.

[cianuro]

Originally Posted by JLAG

Wow nice write up. this is going to help in painting in general.

That was my aim. I believe I saw some of these techniques on Discovery's American Hot Rod once, but just the part where they worked on the clear coats. The rest I just applied it to using spray paint instead of a paint gun with compressor.

[cianuro]

Forgot to add...

All of this was done by hand. I tried using an orbital polisher and a polishing disk for drills, but these devices tend to rip off the coats because they get too hot during the process.

So, practice by hand, do it by hand.

Here's some of the stuff I did on my previous car:

[disaster999]

wow that interior looks like crap

[cianuro]

Originally Posted by disaster999

wow that interior looks like crap

As in dirty, or that you don't like how it looks?

[SlowMoe]

nice final product and write up!

[NitroTrike]

I remember a guy doing his trim in WRB years ago. Looked pretty sick. I don't think he was able to find it in a spray bomb though.

[k2skater]

Originally Posted by disaster999

wow that interior looks like crap

.... what looks crappy about it??

but good write up and paint looks good

[SedonaScooby]

Originally Posted by k2skater

.... what looks crappy about it??

but good write up and paint looks good

probably how trashed the floors look?

and how the new paint is glossy black and how the dash is a light black/dark grey....

the quality is awesome on inside and out, but i do agree with it looking like crap, there is dust and stuff all over...

[1fly05sti]

great write up on the suby part but the interior pieces i think that shiny black gives it a bad look, like cheap i think if people go off to paint their interior pieces a flat black or matte black is the way to go

[wisconsinsubaru]

looks pretty damn good, you took your time