HELP: FF Discoloration Tutorial

[thejurasikfrank]

Hi guys,
Tried following FF discoloration tutorial. I'm at part 1.
I must be doing something wrong: After lightly wetting the surface with turpenoid, I'm applying spots of different 502 abteilung colors. Afterwards, using a wide brush lightly dempt in turpenoid, I gently brush the surface. The result is good but here's my problem:
Spots of paint are still visible were I applied the 502 (see picture).

HELP: FF Discoloration Tutorial

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I tough the tupenoid might be the problem, so I switched brand, same result.... I tried all sort of things, like thining the paint a little before applying, working faster, putting more turpenoid, again same result.
Oh, I should mention that I'm applying the discoloration technique straight on top of my base color (tamya), no FFA or any other protection. Could that be my problem?
I basicaly screwed the whole lower part of my model trying stuff.
Please Help!

[tmajor]

I assume you mean your getting a stippled effect over the base coat with the oils?

It could be that your primer coat and base coat could have built up a rough texture. Tamiya flat colours tend to dry really quick and depending on how your airbrushing can be mostly dry when they hit the model resulting in a build up that can create a rough texture. Sort of like little tiny paint balls stuck all over the surface. This provides lots of little pockets for the oils to get in and stain the surface.

To prevent this you can, before applying your base colour lightly sand your primer coat using a really high grit sand paper like 2000 or higher. I think FF says he uses steel wool to rub down his primer coat. Regardless, before you start applying your base coat, the primer needs to be smooth. I sometimes polish mine a bit with a cloth.

For the base coat, I recently started using Tamiya Paint Retarder which really helps extend the dry time of the paint allowing it to settle down smooth on the model. This is especially true if your thinning with alcohol which evaporates really quick. I generally make the retarder about 10% of the total mix of paint and thinner in the airbrush. I know the paint has gone down good if it looks all wet and shiny on the surface. :)

Best thing to do is experiment on some scrap with different methods. Experiment with some different barrier coats as well, see what kind of results you get. Its always good to have that layer of protection between layers.

Hope this helps. I'm sure other will have some good suggestions as well.

[thejurasikfrank]

That makes a lot of sense: my base coat was a bit grainy due to wrong pressure from my compressor. Thanks to some help from the forum I solved that problem. I sanded down the surface a bit to get a better finish but clearly not enough.
Love the retarder idea, I didn't even knew that kind of stuff was around. I'll get some on my next trip to hobby store.
Before moving on to the top (and more visible) section of the ship I guess I'll do some more sanding and a clearcoat, just to make sure.
Thanks a lot major!
Cheers!

[FichtenFoo]

I've had that happen... the thin layer of turp usually prevents that though which is why I started doing it. I agree that it's likely too grainy a base-coat. Thin the Tamiya more I think. Also don't use glops of paint... just tiny flat smears will do. Also try thinning the 502 slightly as well Looks like it's mostly the blue doing it which was a problem I had as well with some Winton oil paints.

[thejurasikfrank]

Thanks for the tips FF.
When I first started painting the kit I wasn't happy with the color so I repainted it... That meens: grainy primer, first layer of ugly grainy grey color and second layer of magnificent falcon almost not grainy grey color. Somehow this grainy word just keeps on popping.
So, guess what? sanded the whole thing, again that twitching face is soooo appropriate.
Transformed my dauther's old princess electric toothbrush into a sanding device. All credit to Grail for that, saved me couple of hours...
Turns out I had so much paint on that I didn't even have to repaint the kit. Learning... slowly  .
Cleared the whole thing with some FFA. Thank god I did some tests on scraps. Dropped my pressure at about 10-12 psi and tried just to mist it on. Got some spots here and there (too much flat base I suppose) but in the end its not bad. Tomorrow: weathering, take 2.
Thanks again for bringing me back on track!
Cheers

[thejurasikfrank]

Transformed my dauther's old princess electric toothbrush into a sanding device. All credit to Grail for that, saved me couple of hours...

Now that I think of it, the tip was from FilmMkr:
http://fichtenfoo.net/forum/index.php?topic=3441.0
Sorry, me bad.

[tmajor]

Transformed my dauther's old princess electric toothbrush into a sanding device. All credit to Grail for that, saved me couple of hours...

Now that I think of it, the tip was from FilmMkr:
http://fichtenfoo.net/forum/index.php?topic=3441.0
Sorry, me bad.

Thats great. So glad I saw this. There are definitely a couple of those hanging around our house. I'll have to commandeer them :)

[srmalloy]

I saw this question come up in, IIRC, an issue of Fine Scale Modeler; the response was that the dot modulation process needs to be done on a gloss surface; flat paint is microscopically rough to scatter light to eliminate highlights, and the roughness will catch enough paint to prevent it from being spread smoothly, even with a wet layer of thinner. The process that they recommended was to put down a thin coat of FFA, then do the dot modulation, and then add a flat layer to seal the surface and eliminate the shine.

[thejurasikfrank]

Yup, right on!
That's exactly what I did and I ended up with great results.

Cheers

[Grail]

I found that a shiny surface just makes it more like a wash or pin wash. I feel like the point is to keep it matte.
What I do in a case like this where the surface is supposed to look hard like metal is buff it lightly. It allows you to get a slight bit of polish on the surface to move paint around and it still looks matte. Or more to the point, like shiny hard surfaces under paint.

I have also used satin coats, but I'm surprised you got the same look with gloss. I do the same as fichtenfoo and use matte most of the time. 
Have you tried applying the oils really lightly too? As in light pressure? I found if I hit the wood part f the brush, I was dotting too hard for example.

ANyhow, glad it's working for ya JF. :)

Actually, one more thing I did that worked in the past was buying crappier paint. ( it doesn't stick as well and has crappy pigmentation, great for weathering )

Cheers.

[thejurasikfrank]

Have you tried applying the oils really lightly too? As in light pressure? I found if I hit the wood part f the brush, I was dotting too hard for example.
Cheers.

You know what? I think that was another major part of my problem; not saying that I was slamming the brush on the kit, but I could have been more delicate.

Thanks Grail, once again, great input!
Cheers

[Grail]

not saying that I was slamming the brush on the kit, but I could have been more delicate.

Yeah, I have "thought" that I was using appropriate pressure and had the same thing happen.

Crappy oils and real light pressure helped me out. Now I do that technique on matte surfaces with no problem.
I'm not too shy with the orderless turp either.
As a little fix up, any obvious screw up paint spots that look a little lame I turn into blaster burns with pigments. 

Glad to know something is working for you.

[thejurasikfrank]

As a little fix up, any obvious screw up paint spots that look a little lame I turn into blaster burns with pigments. 

Great idea! Beats, sanding things down 

Cheers