hi can anyone tell me how to weather a model using a wash I am new to modeling so if you can be as basic as possible I tried to wash a sdkfz 251/1 model and the wash went into the cracks but stayed on top of the model and would not come off so I had to airbrush it again I don't understand the washes very well thanks for any help or suggestions

Welcome to Armorama!
Sounds like you're getting close and you know where you're going. Try using a much smaller brush, no larger than a really good, fine pointed #1. Smaller if you can. Dip your point into the wash, should be about 90% thinner. Dab it lightly at recessed panel junctures and capillary action will pull the tint along hte sepression. WHen it's dry, you may need do add couple more applications,
Washes work best with enamels and oils, the pigment is generlaly finer and the viscosity of thinner is more conducive to capilarry action than water.
You can improve the effect by laying down a gloss acrylic barrier after you've added your decals. Yes, decals should be applied before the wash so they'll blend into the model better.
Hope this helps clarify things.

Good points all Al.

A couple more. If your color is laying on top and not flowing into where you want it then it is possible that your paint is not properly thinned. I go by sight rather than a actual ratio but remember, a wash is more tainted thinner than thinned paint. Also, try adding a drop of dishwashing liquid to the wash. This reduces surface tension and helps it flow into cracks and crevices where it belongs.

thanks for the advice guy's I will give it a shot

guys, great advice, iam struggling with washes also!

Thanks
Frank

Check out this article

http://www.missing-lynx.com/rare_world/rw04.htm

It should give you enough knowledge on how to do a wash, different types of it too.

I suggest you also check out other weathering articles by Mig Jimenez

http://www.missing-lynx.com/rareworld.htm