Author Topic: Dark spots after painting  (Read 3303 times)

September 19, 2006, 05:22:29 PM
Read 3303 times

go.go

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Hello all, I have recently gotten into modelling and is currently working a on gundam.  I've done alot of research and read alot of tutorials, but I've run into a problem as of late.  I've done the putting/sanding/priming stage and decided to start spraying my gundam today (with an airbrush), where I realized a problem that hasn't been mentioned in any of the tutorials I have read.  After spraying my 3rd coat of laquer paint I noticed some dark spots on the peice, and came to figure that they were the colour of the putty used previously.  Has anyone come across the same problem as me? Did I not do enough sanding or priming in the earlier stages? Or have I just not sprayed enough coats to cover the spots?  These darker areas are extremely visible and I hope there is there a solution to this.  I've search the forum for this topic and have had no luck, sorry if this was mention before.

September 19, 2006, 05:27:01 PM
Reply #1

FichtenFoo

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Can you post an image (non-blurry please) of your problem parts?

September 20, 2006, 09:35:05 PM
Reply #2

go.go

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http://i86.photobucket.com/albums/k106/Go-/ZGMF-X666S%20Legend/darkspot.jpg

Ok here it is.  Though its very hard to tell in the photo (poor camera), the actual spots are more visible in reality.  Having some spare time tonight, I decided to put on a few more layers which made it less visible although not completely gone, and plan to do a few more layers to see if I can fully cover it.  I forgot to mention, when i did my priming, I sprayed really quickly, covering parts I needed to and leaving surfaces that were fine un primed.  Would this have contributed to my problem? Should I always prime entirely, as I would with the actual paint layers?

MOD EDIT: IMAGE TOO WIDE. PLEASE READ IMAGE POSTING GUIDELINES

September 20, 2006, 09:56:28 PM
Reply #3

Artic Fox

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you left spots on the same part un-primed? if so that could count for it, seeing as your spraying onto two different base colors.

September 20, 2006, 10:14:19 PM
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pu_rplecow

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Definitely prime everything...  8)
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I'm trying to decrease my talk : model ratio.
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September 21, 2006, 02:51:16 AM
Reply #5

wingnut

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hmmm...

step-back a bit...decide if you are going to do some weathering on this kit...is this happening all over your kit or is this just happening at the bottom of the feet like what you're showing??? then i think your "dilemna" is actually a blessing...

not unless you're going for a showroom "sparkly" finish...then it's paint stripping time...

justmy2cents...
Everyone grows old, but not everybody grows up..."

September 21, 2006, 12:16:25 PM
Reply #6

G-Sentinel

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possibly your just spraying to much in an area. Did you paint it with the bottom of the foot facing the ground? Because if so, paint will build up in packets towards the bottom an object. Mabye that's what it is.
ou don't need to be hot to model, You just need the right tools.

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September 21, 2006, 10:32:39 PM
Reply #7

T1000

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Quote from: "go.go"
http://i86.photobucket.com/albums/k106/Go-/ZGMF-X666S%20Legend/darkspot.jpg

Ok here it is.  Though its very hard to tell in the photo (poor camera), the actual spots are more visible in reality.  Having some spare time tonight, I decided to put on a few more layers which made it less visible although not completely gone, and plan to do a few more layers to see if I can fully cover it.  I forgot to mention, when i did my priming, I sprayed really quickly, covering parts I needed to and leaving surfaces that were fine un primed.  Would this have contributed to my problem? Should I always prime entirely, as I would with the actual paint layers?

MOD EDIT: IMAGE TOO WIDE. PLEASE READ IMAGE POSTING GUIDELINES


From your pics, I noticed those "black spots" are not actually spots but patches of dark and light undercoat contrasts. If I am not wrong, this problem only occur on red colour right?

I think this is becos for Red colour (and red colour only), it is VERY sensitive to the colour of the undercoat you used. If you do not believe me,  you can spray a layer or two of red over a surface primed with grey surfacer and over a surface primed with white surfacer. You will realise that the red over the grey surfacer will look more dull, regardless of how many layers of red you sprayed.

So my deduction is that the undercoat which you have primed is in-consistent. Meaning that it may be un evenly primed. Esp for red, care have to be taken for the undercoat. So do make sure it is evenly primed. If you intend to use this characteristic to your advantage, it can also be done with a technique called "Reverse Shading". This is how you do it:

1. First prime with a grey surfacer.
2. Use Gloss White to spray the center, leaving the grey shades on the edges
3. Then spray on the red. Since Red is sensitive to the undercoat, you will see a nice shade naturally.

So for now, I guess the best thing you can do is sand it off, prime it with grey and try this reverse shading technique...  8)

September 21, 2006, 11:05:39 PM
Reply #8

go.go

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wow! T1000 I think you are right on.  And yes this only happening to my red peices.  I will be sure to take more care with color red from now on.  As for my peices, they are drying on their 8th layer atm and the darker shades are much less visible(though not rid 100%) so I'll prolly just gonna leave it the way it is. (stripping lacquer paint is a b!tch) Anyhow, thx to all the guys that replied, I've learned so much!