-washes....after I primed the models with white primer, I applied the basecoat, later I wanted to do a wash with thinner thinned colour all seemes to go well but when I reached the fifth model and looked at the first I saw to my horror that the thinner wash ate away the base coat!I screamed bloody mayhem and cleaned them up as fast as I could, I got dead scared and have no clue what to do now, anyone?

Okay, calm down. :-)
If you are using acrylics, use a good matt or Satin Varnish to seal it in before washing.
I suggest Vallejo for these products. Let this coat set for a day and then begin the washes.

Andrew

:-) Basically you require a protective coat between your colour coats and the wash. There are lots of thoughts on this and each to there own. As I mentioned in your post about decals I use Klear. You can find a more in depth explanation of it's use in my article on the Bf110G-2 Here
I brush it on but it can be sprayed. :-)
Mal

I mostly use Model Master Enamels in my models and before applying the oil wash I give a coat of Clear Varnish (Humbrol). The same when I use Acrylics but in this case the Clear coat is acrylic also.
One important thing in both cases is that I let the coats to dry well between eachone, and the last coat (the clear one), I let it dry for about 48 hs so it can reach the propper hardness.