A wash is just a very thin, India Ink consistency mixture of dark earth tones to black, which usually is a oil based paint and Mineral spirits. Most modelers seal the paint with a clear gloss to protect it from the Mineral Spirits and it allows the Wash to flow into all the nooks and crannies. Once dry, you have achieved both a shadow effect and dirtied up the clean raw paint.

There are hundreds of videos on U tube on modeling washes. MIG has a few really good ones.

Hope my short explanation helped.
Joel

Thanks Joe!!!! Very clear, I will looking for in U tube

Pipes... a lot of pipes!!!

After many time, I still with the Horten. I try some weathering with pastels. Brown, red and light grey and some dry brush with silver in black area in turbines. Welcome advices.

Here the original model

Alfredo,
Those twin engines look fantastic compared to your posted picture of the real ones. The level of detail for the engine sub assembly is just amazing.
Joel

Thanks I glad you like it