Painting buildings with acrylics, advice appreciated

[ColinK]

I'm currently working on the castle seen in the picture below.  In the past I have painted buildings with enamel paints working as follows.

 

Step 1, Paint base colour.

Step 2,  Pick out individual stones in slight variations of the base colour.

Step 3,  Paint the mortar courses by running a dark wash into the joins, then rub any excess off.

Step 4,  A light coat of dirt airbrushed over lightly.

 

I'm now using acrylics but have hit on a problem.  Steps 1 and 2 are no problem, but step 3 is.  How do you paint the mortar courses with acrylics as they dry too quickly, don't run so easily into the cracks and dry before i can wipe any excess away?

 

The building is G scale, but I've had the same problem in 00, where I had to revert to enamels.

 

[tom q vaxy]

are you using a proprietary wash or making your own? 

 

https://tangibleday.com/top-7-best-washes-for-painting-miniatures-and-models/

 

if you have been using enamels, I assume your base material is non-porous (rather than foam). have you tried a clear sealer? and then a wash? the scale you're working may be offering area too great for a wash to flow (?)

 

I would be interested to learn if anyone uses water soluble oil paints for a wash. I have only used pre-mixed since it serves me well enough.

[tom q vaxy]

 

[ColinK]

 Very helpful videos, many thanks.

[ColinK]

Sunny day so I had a go working outside  The castle is G scale so its pretty big and did take all afternoon.   First I picked our some individual stones in slightly different colours.  Then made my own wash using a mix of the sandy base colour, roof dirt and thinners.  Tried to work the wash into all the nooks and crannies then rubbed some of it off with a rag.  Its a bit easier with enamels because they take hours to dry, compared with about 10 minutes max for the acrylics.  But by working quickly it can be done and no nasty smells from the paint.  Normally I would finish the job off with a gentle waft of ‘dirt’ using my airbrush, but I don’t think I need to this time.  I think the result is OK - what do people think?  
 

[ColinK]

Also used the washes on a G scale wagon.  The left side is as out of the box, the right side has had a dark wash applied.