Paint discoloration with salt weathering

[Gyro]

I've been experimenting with salt weathering. The affect works well, but I'm having a problem with the paint I can't figure out. The paint near the salt is getting discolored:

http://www.flickr.com/photos/ringlaser/6439184325/

You can see a discoloration of the grey paint to a lighter shade (sort of a fog/stain). This also happened with another model with the color yellow (took many coats of paint to eliminate).

In both cases I'm using Tamiya Acrylic applied with an airbrush.

Any one have an idea why this is happening?

Thanks.

[Mr. Badwrench]

My guess is the salt is pulling the water out of the paint, causing it to cure unevenly. The good news is, this is part of what the salt method is supposed to do. The reason to use salt rather than, say, peanut butter or dirt, is because salt does weird things with the paint. Don't look at it as a bad thing, think of it as more realistic looking damage. In addition, when you scrub the salt off, don't be gentle. Allow the salt crystals to scratch and abrade the surrounding surface. Then when you add a wash or filter over the chipped area, it will soak into it, adding color and depth.

[Rogviler]

Yeah, I was going to say it looks about perfect.

If you like the effect without the change to the paint, you can experiment with other granulated substances. I've used sand and hairspray before with good results.

-Rog

[ajmadison]

Hate to say this, but the first modelers to recommend "Salt Masking" wanted and desired this discoloration and made a point of mentioning it in their write ups. I remember this from the beginning, and am looking forward to working on model that needed this kind of heavy weathering between different colors or layers of paint.

I realize this wasn't your desired effect, so you should try another substance that won't chemically or physically interact with your paint.

Another idea worth considering is to severely abuse your masking tape before applying it to your model. Cut it into wavy shapes then roughen the edges with a very low numbered sandpaper.

[Kylwell]

It's the moisture in the paint causing the salt to migrate a bit. Yes, this is desired by some people. I've noticed it happens more with dusty salt (stuff that's been beating around and developed salt powder) that cleaner stuff (.i.e. top of the bag vs bottom of the bag). No fix that I know of, I've always just added it to the weathering.

[rocketrider]

if that is not the desired effect, you can try rubber cement. Althought not the exact same outcome, it worked well on my Droid Federation Tank.

glen

[Gyro]

Thanks everyone for the responses.

My guess is the salt is pulling the water out of the paint, causing it to cure unevenly.

This seems to be the prevailing answer and what I was suspecting. I wonder if sea salt will work better.

If you like the effect without the change to the paint, you can experiment with other granulated substances. I've used sand and hairspray before with good results.

Now that is an interesting idea - sand. Though I wonder if it will stick to the model as well as salt.

Hate to say this, but the first modelers to recommend "Salt Masking" wanted and desired this discoloration and made a point of mentioning it in their write ups.

Interesting. The instructions I found on the web didn't mention this nor do I see it in their pictures:

http://www.swannysmodels.com/Salting.html

http://www.scalemodelguide.com/guide/pa ... eathering/

http://www.aeroscale.co.uk/modules.php? ... artid=1307

They also don't really say what paint they are using. I'm thinking this affect won't happen with oil based enamels. I'm going to experiment with Testors oil enamels to see if the same thing happens

[Rogviler]

If you like the effect without the change to the paint, you can experiment with other granulated substances. I've used sand and hairspray before with good results.

Now that is an interesting idea - sand. Though I wonder if it will stick to the model as well as salt.

That's why you need to use hairspray instead of water. By the way, some people use this method with salt too. Use something really cheap and sticky like Aqua Net and work quickly. You can also use a coating of plain hairspray to "chip" the paint by hand after it dries as it gives a bit of a barrier between the paint layers.

-Rog

[Mr. Badwrench]

Interesting. The instructions I found on the web didn't mention this nor do I see it in their pictures:

http://www.swannysmodels.com/Salting.html

http://www.scalemodelguide.com/guide/pa ... eathering/

http://www.aeroscale.co.uk/modules.php? ... artid=1307

They also don't really say what paint they are using. I'm thinking this affect won't happen with oil based enamels. I'm going to experiment with Testors oil enamels to see if the same thing happens

The first place I saw this technique was in an article in FSM a few years ago. It started showing up on the web shortly thereafter, including the Swanny's Models link. Paint discoloration, scratching and abrasion were mentioned there as key features. It does discolor enamels too, but not as severely. Even though this is not what you intended, I still think it looks good, and will look even better with some additional weathering.

[Gyro]

It does discolor enamels too, but not as severely. Even though this is not what you intended, I still think it looks good, and will look even better with some additional weathering.

Thanks for the compliment. I guess I'm weird, but I really don't like the discoloration in this case.

[TER-OR]

You can use a make-up sponge to wipe the area down, or you can lightly buff it.