Painting door jambs

D

DWinTX

Member
I'm doing the final sanding (up to 400) in preparation of laying the sealer/base/clear on my 70 Corvette. I'm trying to plan the timing of doing this since there are time windows for each step. Currently the doors, hood and T-Tops are off and I've been prepping them separately. My color, Ontario Orange, is a semi-metallic so I know I need to put everthing back on before spraying the base for consistency.

How would you suggest painting the jambs before I reassemble? I've seen some videos where they don't do any taping. They just spray the jams and some overspray gets on the fenders and quarters. I guess that's OK in the sense that they are going to be sprayed over, but what about the clear? If you base and clear the jambs, and some clear overspray gets on the fenders/quarters, is that a problem to lay base over the clear when you're painting the rest of the car? On the other hand, I could tape it off, but then I guess you have a hard line. Does that go away with the cut and buff?
 
A hard line can be problematic. There are ways to soften it with backtaping, where you kind of fold the tape lengthwise so the sticky side is out, and use that along the edge to make a softer line. It's a little hard to explain. It's not too often at all that we jamb separately from exterior, but when it's necessary I will typically just let the overspray get on the exterior a little (it must be sanded of course). To avoid sensitivity issues, the base is kept confined as close to the jamb as possible, and the clear is extended out a few inches more. This stuff on the exterior must be sanded before continuing, and having the clear completely cover the base prevents problems that can arise from sanding through the clear into the base, it's those fresh featheredges of base/clear that can be a problem, not the clear itself. Hope this makes sense. There are multiple ways to get this done, let's see what the pros say!
 
I've always painted cars apart, usually the body and door/hood/decklid in different sessions using both solids and metallics. I never had a color matching problem, so I would paint the body by itself which makes it easy to get the jams nice and slick and avoid having to cut and buff. I usually put at least 4 clear coats on the body and two in the jams, so skip the jams the first two clear coats. Make your last coat of clear a flow coat.
 
I'm kinda afraid to do them apart. This is my first time. I did a test panel and it came out pretty nice, but I did get a little streaking in one place. I don't know if it's because my overlap/distance/spray angle wasn't right (I'm sure they were all a little off), or I should have done a third base coat.

Crashtech, I know what you mean on the backtaping. Might try that. Thanks guys.
 
I have done it both ways without any problems. The key is to be consistent in your application process.
Here is a truck cab being masked off and painted with a tri-stage paint.
Base Coat Stage 1.JPG


Dash Base Coat Stage 1.JPG


You can see the door leaning on the wall and being used to adjust my spray pattern.
The engine compartment was completely painted and cleared prior to engine installation.

Doors being sprayed:
Door inside Cleared.JPG


Assembled:
Door Left Rear View.JPG


Door Right Rear View.JPG


This car was painted assembled:
Right Front Cleared.JPG


Takes some effort to get the jambs but it can be done:
Right Door Jam Cleared.JPG
 
Those look great. Like you say, the key is consistency. I'm not sure that I have that after painting just one hood. But it sure would be a lot easier...
 
I
I’m not a pro - they pro’s may scoff at this but I see it being done on TV too- “orientation coat” - after you have good coverage with a metallic paint job - last coat = turn pressure/ fluid up just a bit, back off several inches and just spray in a semi random motion. It will fill in the “tiger stripes” - works for me and no one has ever complained about un- evenness- called a “drop coat”
 
Thanks Dave. What kind of motion do you use? Would it make sense to turn the gun sideways, perpendicular to the length of the car, and spray that coat up and down?
 
I have seen horizontal, vertical and diagonal passes done. I used this technique when spraying HOK brandywine Kandy base several years ago. The coverage was poor and it was necessary for me.

I don’t think this is needed with a quality metallic base. Chris and others have explained how to spray these.

Don
 
Old school fog coat or fogging with ss metallics. With BC I think just three or four coats of base may be better but ask Chris and others :)
To be clear, with ss metallics in the 70's some were pretty thin and didn't cover well. You could hardly spray straight up with silvers and golds without streaking, we were taught by manufacturer reps to fog over the last coat to even streaking or mottling. Pressure up, fan out, back off and fog directly over your last coat while it was wet. Base doesn't spray like single stage metallics, I don't think you'll need to fog coat.
Just re-read, Dave and Don maybe right, I stand corrected. That Ontario orange is a beautiful color. I think in base clear it'll be easier to spray than it was in "acrylic enamel".
 
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I already have the base, it's Cromabase, which I think is high quality. I sprayed an extra hood as a test panel, and there was a slight bit of streakiness. Not bad, it's hard to see, but it's there. I didn't really notice it until I put it in the sun. Even then, it's not really that bad.

Here are some pics, but it doesn't really show:

My first BC/CC panel

Some of you guys have been helping me with my first attempt at painting (outside of painting one engine bay with SS). Thank you very much for that. I'm restoring my 70 Corvette and decided to try a test panel before I do the whole car. I'm using an aftermarket hood on the car, so I thought...
www.spiuserforum.com

I think it's probably either that I should have sprayed 3 coats instead of 2, or more likely, that I just wasn't consistent in my spraying technique. This is my first time painting.
 
Another factor in metallic consistency is the use of a quality gun (they atomize better). Not that you have to use a stupid expensive gun. You can lay down metallics with lower end guns but its not as easy. If you do have some streaking, a "fog coat" as mentioned above will generally sort it out.
 
For modern basecoats using a "blender" or intercoat like SPI's is much safer and preferred technique than a drop coat. If you have experience doing a drop it's ok. But if you are a noobie it's easy to really make a mess trying to do it.
First thing is to always use a high quality reducer. Meaning reducer that the basecoat TDS calls for or SPI Reducer. No economy reducer....ever. SPI is the best urethane reducer I have used and I use that whenever possible. And when doing an overall use slow, no matter what the temperature or season is. (ideally you want to be painting in at least 68 degree temps). Just give it more time to flash.
I never do drops, if I'm having an issue, I use blender or an intercoat. If you search "blender" and my username you will find a lot of posts where I cover it and also proper technique when spraying. Using the proper techniques will keep you from having issues 9x out of 10. When you do that is where blender comes in. Usually it's used when blending a repair.
Also like the guys said above usually the issue is not having enough coverage or tilting the gun one way or another. Modern basecoat the only colors that can be problematic are the silvers and golds. Darker colors if you are using proper technique are almost never an issue.
Don't spray base wet. Light-medium to medium coats are all that you need. Usually I spray four coats, all light-medium on any metallic I think is going to be problematic. Using a quality slow reducer allows you to spray light and not have issues with dry overspray too. Always a good idea to tack between coats or every other coat as well.
 
As for your first question, I've seen guys tape off a vehicle so that they could open and close the doors or have the doors and other jamb areas open like "68 showed above and do it that way. I've never like that way myself because it makes spraying it more difficult, and being relatively unlucky I usually have something go wrong. Plus my "OCD" makes me want to get it looking a certain way and I personally can't achieve that doing it the technique described above.

Before I describe this let me say I feel the best method is to spray everything separately, but oriented in the correct position as it would be on the car. Everything should be hung so that you can spray both backside and front, all at once. Ideal but oftentimes not possible or with some color and finishes not possible. Candies would be one. Flaming something would be another. So what I describe below is how I do it. Labor intensive and uses a lot of tape, but it does work for me.

Only way I have had success on an overall (not collision repair type quality) is to get to the point where I am ready to do the final wet sand on everything. I then finish the jambs and paint all the jamb areas. I will back tape like Crash describes, and also mask everything else off. You never want a hard line as it is very difficult to remove it without affecting the underlying area. Backtaping works best with minimum 1 1/2" tape, 2" works better. Just lay it back on itself and use more tape to hold it in place. Done right you can do wonders backtaping.
So after masking and shooting the jambs, let them cure for a several days so that you can tape the jambs without affecting the clear. That is important, because the tape will be on there for a while. I then will tape the jambs, backs of doors etc. Door jambs, trunk jambs, backs of doors I only will use tape. Tape it up completely. Inside edge of a door I tape to the point where the skin is folded over to the inner door. I leave that untaped. If I have to reassemble the doors or other panels back to the body I will do a backtape to ensure I have no hard line. Any slight fuzziness is easily taken care of afterward with sanding and buffing. Keep that spot (like on the rocker) inside the door though to ensure that UV light doesn't eventually cause it to show. Done right it's not an issue and will last many years. Hoods and fender jambs I will tape and sometimes use paper, but tape works really well and allows for everything to shut and not have to worry about bunching like masking paper does. Taping to a hard line close to the edge of the exterior (like the with a door skin or where the quarter skin folds over) works well so look for those areas when taping. Give those untaped areas a little scuff with a grey pad before shooting the exterior. Just be prepared to use some tape. I use a combination of 3/4", 1 1/2", and 2" when doing this. 2" works best for backtaping. It's easier to tape then reasssemble than it is to reassemble then tape. Then final alignment once everything is painted.
Keep in mind it's a lot of work and requires some patience
 
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