Paint assembled or not

[SRC]

I would love to hear from some experienced shops and painters on their paint process. One common debate in our shop is the decision to cut in then assemble to final paint....or paint while completely apart.

Of course there are many considerations with regard to color choice, metallics, pearls etc.
So disassembled paint is not always even possible.

I've seen many SEMA build posts here and I have see the progress photos done both ways.
With the many products available to correctly tape off jambs I would like to see what others are using. Currently I'm using the 3M 3 step tape that peels in layers from sealer, to base then clear.

Your comments and advice are appreciated.

Thank you

[Rob68427]

I would say assembled. If you don't assemble it Make Sure you have all the panels aligned as they would be mounted on the car. Example doors Don't lay them on a horse and paint them. They should be angled straight up and down. Especially with met. pearls, and so forth. You want the met. to lay the same.
In the shop I work at we got a beautiful 70 Monte Carlo it was painted black met. base with blue candy over it.
But when you look at the paint and panels they don't look the same the tail and front light bezels look like a different color than the rest of the car. Because they weren't painted on the same angle as they would be mounted.
We had to fix a couple of scratches in the paint. It's kinda funny he was picking out the smallest of scratches but he didn't ask us to fix the bezels.

I hope this helps

[elitecustombody]

I like to paint everything apart, that way every panel gets proper attention and material coverage around all edges, so there is no chance of overspray or tape lines. Few important things to remember is to have everything assembled and guide holes drilled for easy re-assembly after paint,remember or write down precisely how many coats of every product applied at what temp and air pressure.

[SRC]

Thanks for the advice. Good idea on the air and temp, somethings that just taken for granted.

[Happyfunballs]

Solid color apart, metallics and pearls together. A simple spray pattern can make the metallics and pearls line up differently giving the illusion of a mis-match in color, especially multi-layered candies.

[ROBS6T8]

Thanks for asking this question. I'm going HOK tangelo and was wanting to do it in pieces. people telling me not to. i was going to mix all the quarts purchased together in a gallon can to avoind any differences there. i already knew about the painting the panels as they hang on the car. I'm not building a show car! lol

[elitecustombody]

You can get the color on when the car is together,apply a coat of intercoat clear, which is nothing more than basecoat binder, take it apart ,touch up areas that were hard to reach and shoot the panels with clear.I like to have nice smooth paint finish in door jambs and around all edges of the fenders and there is no way it can be done with car assembled.

[Happyfunballs]

I have had terrible luck in the past with HOK's SG100 intercoat clear. It never dried and remained tacky. I was told that I had a bad batch and when they replaced it, the same thing happened. Not sure if I mixed it wrong (it isn't THAT difficult) or if it's the nature of the clear. I haven't used it since, which sucks, cause it's a valuable tool.

[elitecustombody]

You can use basecoat binder instead of HOK SG100, I actually use Matrix Color Blender MPB-500, this stuff works great, dries quick,doesn't build up and very easy to spray.

[ROBS6T8]

But then you get into the mixing of products between mfg's! I thought this was a no-no. Pick a brand and stick with them through the end?

[Happyfunballs]

I tend to not intermix companies within the step. IOW, I have no problem with primers from company A, base coats from company B, and clears from company C, but I'm leery of doing what Stefan recommended, although there probably isn't anything wrong with it. Just goes against my grain. (I do intend to look into it however)


Edit: Looks like MCB (http://www.matrixsystem.com/docs/tech/Color_Blender.pdf) is compatible with most things, HOK should be no different. Thanks for the tip.

[elitecustombody]

I mainly use Matrix, so I don't have a problem, but mixing compatible products shouldn't make much difference if any. For example I use Evercoat G2 primer on everything because I like the high-build properties, which eliminates the need to re-prime and quite frankly it has never failed ,15k paint job or 3k, and the best part, it's under $60 a kit. On flexible urethane parts I use Sherwin Williams P30,it's very flexible, easy to sand and has amazing adhesion properties. So I do not mind mixing brands ,as long as I know I end up with positive results .

[Happyfunballs]

Love the G2. I switched to it on the last job having used the Mar-hyde 2k for years. I gotta spray the rubber bumper covers on my 91 Z28 here shortly and planned on using the G2. I haven't used SW primer in a long time. You prefer it over the G2 for plastic? You're not a flex agent advocate are you?

[elitecustombody]

Try the black G2 ,it's the bomb!Because of high content of zinc ,it sands so much easier than gray. If I were you, I wouldn't use it on urethane bumper of the Z28,unless they have become rock hard. On raw flexible parts I always use Plastic Magic by Urethane Supply Company,it's great adhesion promoter,used it for very long time,then I prime with SW P30,. What's nice about P30, is that it comes in variety of colors,so it makes chips not as noticeable,sometimes I even mix together for a very close color, it also can be converted into a sealer,it is very dense and few ounces mixed can cover quite a bit go the only downside to it is the cost, I think it's between $300-400 a gallon, but very well worth IMO,once you get a hang of it and know it's capabilities. As for flex agent, I have a opinion that if something gets hit, it will get damaged, needing repairs, most of the products we use nowadays are more flexible than old lacquer.Using flex agent might be OK, but if you ever tried buffing paint that had this stuff mixed in, you'd know, also I just finished doing a color change on 93 Honda that was painted with flex agent, that garbage would not feather ,it kept rolling off, needless to say I ended up buying new bumpers,lol.

[Happyfunballs]

Adhesion promoter? Really? That's almost as bad as the flex agent IMO. Can't bring myself to use it.

[elitecustombody]

No,sir. Adhesion promoter is a must on all flexible plastics that do not have flexible primer, I don't care how hard you try to sand and scuff, the mechanical adhesion is 1 on a scale from 1-10.Most adhesion promoters chemically bond to TPO and many other types of plastics, it's amazing what few coats of adhesion promoter can do. The stuff that I use is like water, it doesn't build up. You spray it one wet first coat, let it flash for 10-15 minutes, come back with medium coat ,let it flash again 10-15 minutes and shoot your color. I've been using it for well over 12 years,it has never failed,and I would recommend it to anyone who wants the paint to stay on . If you deal with alot of late model cars, this stuff is a must. All new Toyota,Lexus,Scion bumpers come in raw shiny black TPO plastic ,and adhesion promoter is the only way to keep the paint on them. I fabricate custom one off bumpers and grilles ,I also deal with Stillen and Street Scene bumpers and other parts that are made out of black urethane and I always use Plastic Magic.

The reason I use Plastic Magic, is because I was using Bulldog and after hitting a raccoon with my 95 Impala SS that had brand new bumper with fresh paint, I had to look for another product that actually works. The paint came off the bumper in about a foot by ten inches sheet,though the bumper didn't even have a scratch, I know it was thoroughly scuffed and washed prior application of Bulldog ,so I made the switch and could not be happier,because I can sleep at night knowing I won't have to re-do customer's bumpers because of poor adhesion.

[Happyfunballs]

Interesting. I put a Street Scene TPO bumper cover on my black 99 F150 (YEARS ago) and used the Mar-Hyde 2k without flex and without adhesion promoter and never had a problem. You're making me nervous. :lmao:

[67 455 Bird ragtop]

I plan on painting the jambs, inner fenders, dash, windshield frame, firewall, etc .. then assembling the car and painting it assembled since it's a metallic.

[Satatic]

Is there a big difference between painting a "metallic" paint job and a "pearl" paint job? I always considered metallic to be the large flakes and pearl to be the small flakes. I painted my car in my garage with a pearl basecoat/ clearcoat in pieces over weeks without orienting things in the way they would hang on the car. IE the doors and fenders were laying on top of paint stands. I had no issues with things matching and meshing with other parts of the car. I did body one day, doors and trunk sometime after, Fenders after, couple other pieces like front panels and spoiler. And hood last. Used 3 different temperatures of reducers. Never even seemed like a big deal to get everything to look the same way.

[ROBS6T8]

Is there a big difference between painting a "metallic" paint job and a "pearl" paint job? I always considered metallic to be the large flakes and pearl to be the small flakes. I painted my car in my garage with a pearl basecoat/ clearcoat in pieces over weeks without orienting things in the way they would hang on the car. IE the doors and fenders were laying on top of paint stands. I had no issues with things matching and meshing with other parts of the car. I did body one day, doors and trunk sometime after, Fenders after, couple other pieces like front panels and spoiler. And hood last. Used 3 different temperatures of reducers. Never even seemed like a big deal to get everything to look the same way.

That's what I was planning on doing. However, I would have the doors and such hanging as if in place when painting them. I'm not building a trailer queen here. I'm going to drive the piss out of her! If it comes out half as nice as the mailbox, I'll be happy!
https://static1.pt-content.com/images/pt/2011/06/mailbox-1.jpg

[MuscleRodz]

it depends on what you are painting and whose paint your using. Solids you can get away with painting apart most the time, but on low coverage colors you better pay attention to number of coats and gun path. Metallics and pearls can be painted apart, but really should be painted at the same time in the booth with panels hanging as they would on the car. That way you minimize any defiations between panels. On candy jobs we jamb the car, assemble for candy, 2-3 coats of clear, disassemble, block and reclear apart.