Im up to the point on my armor model when Im ready to wash. I want to know when you put a wash on a model do you add the wash to the entire model (I mean do you brush the entire model with wash) or do you just add wash to the low spots? I would also like a critique of what Ive done so far to let me know if Ive been on the right path. So far Ive airbrushed a base coat and then added the finish coat using acrylic paint. Then I went ahead and put a clear gloss enamel coat over top to seal and get ready for wash and decals. My next step will be upon completion of wash is to add a dull coat (what type of paint do I use for the dull coat) and apply weathering.

Welcome to Armorama!

You should apply your decals and allow time for them to cure before proceding to the wash stage. You may even want to seal your decals with a dull coat prior to going to the wash stage.

Your dull coat can be enamel, like Testors Model Master, or acrylic. It depends on the type of paint you used as your base coat and what type of paint you use in your washes.

There are two types of techniques to washes. One is to take a big soft brush and literally repaint your model with the wash. The darker color will settle into the crevices and add depth to your model.

The second technique is a pin wash where you take a fine tipped brush and just dab the wash into the areas you want to give shadow to like around bolt heads, panel lines and let the capillary action draw the wash along the low areas.

I use a combination of the two. I will apply the wash over the whole area. Usually using a color like burnt umber (a dark brown) as my primary wash color. Once done, I will use a pin wash to add a black wash to grill areas. I will also do the same thing with rust (I use earth brown) to add a slight wash to areas that may see some rusting.

You'll basically get as many different opinions and techniques as there are folks who respond to this message. There is no wrong way and what works for me may not suit you.

A word of advice is to practice on an old kit or on the underside of your new kit. That way you can use trial and error without ruining the finish.

Robin pretty much covered the topic, but I wanted to add to put the decals on BEFORE the wash, then reseal with the gloss. That way the marking take the same wear and tear as the rest of the vehicle!

HTH

thanks for the advice...Im ready to leave work and get home to work on giving the model a good wash...two more questions question that I have are what ratio paint to thinner to make my wash and if you apply the wash to the entire model do you wipe it off or just let it dry?

I don't use a ratio per se, I just eyeball a little pigment into a small container until it is basically "dirty thinner". I let it dry, but if a big glob of black or brown color gets where I don't want it, I use the corner of a paper towel to wick away the excess.

Gravity will pull the wash down into the cracks and down towards the bottom of the model. I start top and go towards the bottom.

Yep, what Rob said, but I don't cover the whole model. I find it too risky. Also, using a wash just where you want it allows you to use similar paints, i.e., enamel wash over enamel paint, since you're not disturbing the slightly softened paint by running a brush over it.
Also, ignore the magazine stuff about slopping stuff everywhere and wiping off the excess. That's a surefire way of ruining a good paint job and your decals.

Thanks for everyone help....Hopefully everything will turn out great but if not thats alright to because Ive got about 12 more kits I havent even opened yet.