(Karl A) Baking Flour Mortar

While reading an old thread (2010) I came across a reference to a technique for masonry mortar (perhaps stucco) used by Karl A. Here's hoping he might be willing to explain the technique


  • Sure Terry,
    When I get home from work later.


  • edited April 2022
    For everyone/anyone interested in this I will start off by saying that if you are building a SierraWest kit... FOLLOW THE INSTRUCTIONS.

    Brett's instructions, manuals and methods in his kits are the best in the industry, they have been ground breaking and innovative for over 25 years.
    SierraWest has led the way in this industry for well over two decades and continues to be the best kit you will ever build.

    If you open the box, follow the methods and the incredible instructions contained in the manual you will end up with a model that matches the picture on the box.
    Use the methods, learn the techniques and master the modeling.

    The 'plaster smear' technique, and the other techniques described in the manuals are THE best technique to use where advised in the manual, each technique in the manuals are tailored for each casting, for each kit, and for each specific circumstance, they are developed after extensive research, and then proven by thousands of modellers by their excellent results.

    Following Brett's 'plaster smear' technique on the O scale brickwork for the "BlueSky Cookhouse" yields outstanding, and easy results.


  • edited August 2022
    With that said, a circumstance may arise... a stone wall on a diorama, a brick foundation etc...

    My flour mortar method as below.

    Paint your brick/stone color as the base, water or solvent based paint doesn't matter.
    Once dry sprinkle on some regular plain flour.
    1st pic is HO as its the only old pic I could find.


    Rub the flour into the mortar lines with a finger tip and wipe it off of the brick face.
    Wipe with your fingertip at a 45 angle, NOT along the brick lines, this will ensure the flour stays in the mortar lines/recesses but cleans the brick faces.

    (I've recently seen/watched a couple of youtube 'tutorials' on the technique where they wiped along the brick lines with a finger or brush, this obviously results in removing the flour from the grooves/recesses and is NOT the way to do it.)

    Use a small detail brush to get the flour build up out of any window corners or crevasses where you don't want it.
    Some small amount of dust on the brick face is OK as it will dissolve later.

    A recent O scale scratch build. Dry flour sitting in the mortar lines.


    Spray the wall with dullcoat. This will dissolve the minimal dust from the brick face and also set the flour into the mortar lines, give it a semi heavy spray.


    For this build it still looked too white to me. Once dry it was washed liberally with very watered down 'Hippo Grey' craft paint.
    Because of the dullcoat it flowed off of the brick face and settled in the mortar lines.


    Leave it flat to dry, rewash with the grey if needed and leave to dry flat again.


    Straight walls with no weathering.


    Different build with chalk weathering.


    As noted above... FOLLOW THE MANUAL when building your kit,
    this is only an additional/alternative technique for ancillary items you may use.
  • Thanks Karl
  • outstanding results...
  • Anytime Terry, always happy to share.

    Thanks Kevin.
  • I wonder if instead of flour you could use sanded drywall mud dust. I happen to be modelling in 1:1 scale a lot lately, and whenever I sand my mud down I then clean up the dust with a wipe. The dust is fine and just a little bit of water turns it back to the mud.

    Looking forward to when I can stop the 1:1 stuff and get back to 1:87!
  • edited May 2022
    Like real cement powder, the mud 'dust' leaves a smear on the raised surfaces and doesn't dissolve and disappear into the dulcoat as it dries and leaves hazy streaks. Thus not giving the required effect.
    That was my experience with both.

    Also to wipe down the 'mud dust' from the brick faces with a damp cloth you would not be able to use water based paints as they would wipe off and fade, you would need to use floquil or similar which then basically turns it back into the plaster smear technique.

    Flour is cheap and works every time for me, (also much more accessible to everyone) so that's what I use as an alternative when needed.
  • This is a great tip, Karl. Thanks.
  • Thanks glandesjr, your welcome, hope it helps.
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