does anyone know how to apply MIG weatering pigments without causing the rest of the vehicle to become lighter because of the pigments that havent settled?
and how do you make the pigments settle without damaging the vehicle with the thinners?

Welcome to Armorama.
Not 100% sure what you mean by "pigments that haven't settled," but I assume you mean excess. If that is the case, you can just blow it off or brush it off. In terms of sealing pigments, or getting them to stick without damaging the underlying paint, the key is to use a solvent (thinner) that won't attack the paint. I.E., if you've painted in acylics, use turpenoid or mineral spirits; if you painted in enamels, use alcohol.
I suggest searching this site for an article by Adam Wilder on using pigments. He covers this stuff in considerable detail, and he knows what he's doing.
Hope this helps!

Chris,
I was affraid to use MIG powders at first also.

Here is what I do. After painting, washing, dry brusing, etc. I seal the model with Testors Dull Coat. Then I use regular rubbing alchol as my thinner and it works fine and doesn't damage my paint. Check out my Hummer in the features section and my LAV.

Hi and welcome aboard.

The article Steve is refering to can be accessed HERE. This is a very good tutorial on using pigments.

I know that a lot of people use "Future acrylic floor finish" to seal the kit before going berzek with weathering :-)

Another tip.
A lot of folks dont seal the pigment/pastels afterwards, as the flat coat makes a lot of the effect dissapear. If your result is a little heavier than desired, giveing the problematic areas a slight spray will actually reduce or tone down the pigment effect. This has saved my skin on several occasions!

I suggest using future. Prior to using it myself I would run into issues with making my washes and weathering and having areas of my paint come off.

What I like to do is do my overall coat, and then add my camo etc. I then give it two nice coats of Future floor wax. It makes your armor model look more like a car model at this point but have no fear because this stuff works. Next I then add my decals. After decaling I give it a nice coat of Dullcoat laquer to dull it down. Next I do my wash and and shading etc. After that I finish up with my powders or oil mixed washes, then I coat it one more time again with Dull coat laquer to seal everything up.

Since using those 2 future coats, I have not had one area of paint strip! It really locks it in nice!

That is also a good point. Sometimes if this happens for me, I will just have to go over what I did with my powder and pastels, and then make sure that I'm carefull from that point on not to make a smudge with a finger.

thanks people.i fixed up my M113A2 by tamiya nicely. after that i tried the tips i was told...and the result was awesome!thanks