Seal the deck with Testors flat laquer and then carefully wash with a mix of mineral spirits (thinner) and black artists oil paint. This is a developed skill so.....
Test your skill on an old model or a painted piece of scrap to get your bearings with this, and have plenty of Q-tips handy for screw-ups.
I use this same method on armor however use burnt umber in my armor weathering wash.
Black is best for washing ships with........ I have found.