How should I prep for a color change over existing good paint?

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Righty Tighty

Righty Tighty

Blame it on the dog
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Hey all, this is not for a Mopar, so I apologize in advance.

I'm helping a neighbor replace her busted up door and fender, so we found some parts at the junkyard. Her car is red, the replacement door is light blue, and the replacement fender is white. My question is what's the process for prepping the existing parts to paint red?
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My uneducated guess is to sand with maybe 120, 220, or 320 grit, shoot with primer, shoot the color, then clear.

Am I on the right track? Both replacement parts are straight and require no filler -- simply a color change.

I'm also wondering how to remove this trim piece. I can't lower the window. Does it simply snap into place?
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If it matters, the car is a 2010 Camry. Thanks in advance.
 
Sand and spray the door jam and the inside of the fender first, test alignment of new panels and then sand the outer surfaces to paint. Be sure the paint is a good match, otherwise you will have to blend it to the existing paint.
 
Thanks. What grit do you recommend? Am I simply scuffing the surface, or trying to remove any layers?
 
Righty Tighty said:
Thanks. What grit do you recommend? Am I simply scuffing the surface, or trying to remove any layers?
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Take a look at the TDS sheet of the paint you'll be using and it'll usually tell you what grit they recommend.

As far as the surface, it all depends on what type of guarantee you want. Scuff the surface and shoot paint over it and you're rolling the dice on a reaction. No way to tell what will happen.

Me personally, I'd use epoxy primer (prep surface per that TDS sheet first) and then paint over that for peace of mind. So far I haven't seen epoxy react with anything and it kind of seems to give you a "start over from here" layer. Then again I don't paint all that often so this is just general DYI advice.
 
Sand the door or fender that is damaged down far enough to see what color primer or sealer is directly under the red paint. Replicate that when you start painting the replacements. If her car is still drivable, clean it up and take it to the auto paint store you will be using to buy the paint and get them to scan the existing paint so they can feed that info into their computer and make a better match to the older paint, instead of using the stock mix codes. It may still stick out like a sore thumb if you just paint those 2 panels without blending onto the hood and rear door or quarter a little ways. Get on You Tube and watch some of Paint Society's video's. He has several showing how to blend. If the replacement parts are completely dent free, wet sand them really well with 600 before sealing them with same color sealer that was on the original parts under the red. The wrong color sealer will change the color of the base coat. Good luck with it.

:thumbsup:
 
In addition to the advice already given, I would highly recommend using PPG DBC basecoat. PPG formulas are much closer and have more formula variants to choose from than other paint systems. Take the bad fender or gas lid to the paint shop, have them match it and do a spray out.

The belt moulding usually is attached with plastic clips that you will have to replace after removal if they are available separately. If not you may have to purchase the entire mldg if that is the only way to get clips.

You didn't mention the paint code for the car. If it is a 3 stage paint you should plan on blending the hood and rear door or quarter, whichever is the next adjacent. If just 2 stage metallic I would at least blend the rear door or quarter, and would jamb the replacements out, hang them on the car and do the outer panel painting and blending that way.

If it is a solid color with no metallic you may get by with just panel painting the replacement parts if you have a really good match. Totally worth it to spend the money for the PPG DBC for this alone.
 
Thanks everyone, lots of helpful advice.

The damaged fender is already removed, so I'll take it in for a paint match. She already has some paint leftover from when someone else painted her bumper, but it won't be enough for the door, fender, and blending. The paint is metallic, but I don't know if it's 2 or 3 stage -- I'm a complete novice when it comes to paint & body work.

So, I'll sand the damaged panel to get the correct color of the sealer. Wet sand the replacements with 600, epoxy primer, sealer. Paint the jambs and inside of the fender off the car, hang them on the car, then paint & blend as necessary. Does that sound about right?

And a quick search says I can buy a replacement belt moulding fairly cheaply.
 
Talk to the guy at the paint store about the sealer. Sealer is usually epoxy primer that is thinned out more so it goes on smoother. If that's the case with their sealer, that may save you a step. If you don't have any degreaser, get you some of that and some tack rags. They will have some blender that is in a spray bomb, to spray on the point the new clear meets the old clear, so ask about that too. You just hit the edge of the new clear with it and it melts it and the old together. What size is the tip on your spray gun? 1.3 or 1.4 is best for everything you will be spraying.
 
Thank you. I'll ask about the sealer and blender while I'm there. I do have tack cloth and lots of degreaser, so I'm good in that dept. I'm glad you mentioned tip size, I would've forgotten to check.
 
If your talking Base coat clearcoat I sand the adjacent panel with 1000 grit. Paint said part in base color then blend color partway into adjacent panel, then clearcoat all. No blender needed.
 
JDMopar said:
If yours is a bigger one, like 1.7 or 1.8 that is for primer, you can get one of the cheap Harbor Freight purple guns that is 1.4
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I do have one of the purple guns, a Bostitch, and a Nieko. I don't remember the tip sizes of the other two.
Kendog 170 said:
If your talking Base coat clearcoat I sand the adjacent panel with 1000 grit. Paint said part in base color then blend color partway into adjacent panel, then clearcoat all. No blender needed.
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One of her coworkers painted her bumper a while back, but it looks pretty rough. Maybe I'll test out my skills and redo her bumper while I'm at it. If I do that, would it make sense to just shoot clear over the entire car?
 
Righty Tighty said:
I do have one of the purple guns, a Bostitch, and a Nieko. I don't remember the tip sizes of the other two.

One of her coworkers painted her bumper a while back, but it looks pretty rough. Maybe I'll test out my skills and redo her bumper while I'm at it. If I do that, would it make sense to just shoot clear over the entire car?
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She must be pretty hot!
 
Alright, alright, I won't shoot clear over the entire car. But yes, she's pretty easy on the eyes. Were very good friends--I wouldn't do this for just any old neighbor.

I finally had some time to get started. Wet sanded both pieces and primed the fender. Heading out of town this weekend and will try to get this buttoned up on Sunday. I appreciate the help so far, this ain't too difficult...yet.

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Just curious as to what color the factory primer/sealer under the red on her car was? I had to get the tailgate fixed on my red Dodge truck. The shop used light gray primer/sealer and sprayed the red and clear, which turned out beautiful except being the wrong color. Factory put black or dark gray under the red. Now that I know more what I'm doing, I'm gonna redo the tailgate and a nice factory step bumper so it will match.
 
It was light gray. I remembered the advice here and I sanded a patch on the old fender to check.
 
So far, so good. Shot the jambs with base and clear. The times between coats were much shorter than I was expecting, so the process moved quickly. I'll hang the door and fender on the car tomorrow and finish up.

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Dang dude....that looks good! Shines good, so you weren't afraid to lay the clear to it on the 2nd coat. When you give a progress report after you get the door and fender on, maybe just mumble a little bit until the very end word. "I'm mmfd bblrzt door nnaqrt fndrz bwc hung."

:rofl:
 
One thing I have been taught is different colors, some are way more transparent than pothers, thus require more coats. I also figure some brands of paint and their "levels" have more solids and cover better.
Another thing, IF a person, like me, does not have proper lighting, it is hard to tell whats what!!
 
10-4 on enough lighting! When I built my garage, I made sure the separate room where I do my painting had enough lights to burn a wet mule running...lol.
 
JDMopar said:
Dang dude....that looks good! Shines good, so you weren't afraid to lay the clear to it on the 2nd coat. When you give a progress report after you get the door and fender on, maybe just mumble a little bit until the very end word. "I'm mmfd bblrzt door nnaqrt fndrz bwc hung."

:rofl:
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Thanks guys. The instructions for the base said 3-4 coats, so I decided on 3 for the jambs and I'll probably do at least 4 for the exterior The clear said 2 coats, so that's what I did.

Should I have been more hesitant to lay the clear down? It was actually surprisingly easy.
 
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