Hello, I know this subject has been discussed in previous articles but I really need expert advice on how to come up with a decent looking brick wall mortar.
I’ll explain what I did so far and then you can tell me what I did wrong and what I should have done.
First I must tell you that I’m working on a plastic kit from Walthers, McGraw Oil.
I started by giving the wall a light coat of white water based primer.
Then I painted the wall with the base colour for the brick, I used a mix of 3 water based acrylic paints.
I let it dry for 24 hrs then I applied a coat of drywall plaster to make my brick wall mortar.
I wiped off the excess plaster and let it dry, then I wipe the brick wall with a water dampened piece of cotton and then the brick wall paint starts to come off…
I tried using rubbing alchool and the same thing happens, I also tried pastel chalk powder for the mortar joints and when I start cleaning my brick wall, everything starts to come off again…
After painting my brick wall with the desired colour, what can I use to make my brick mortar so when I clean it up afterwards I don’t wipe the paint off my brick wall ???
I tried different methods but now I’m kind of desperate and going around in circles.
I use dry Hydrocal for my mortar. I rub it in, lightly brush off the excess, and then mist the walls with water, sprayed above horizontally and allowed to fall like rain. The walls must be horizontal to do this, so it’s better to mortar before assembling the building. It needs to be toned down with a thin India Ink wash afterwards, because the Hydrocal is very, very white.
I had good luck with that same kit using straight sheetrock compound. i rubbed it in to the mortar lines with my finger, let it dry, and washed it off the bricks with a damp sponge. then gave it a wash with thinned black paint, and sealed it with dull coat. i like the way it came out.
I agree. The paint shouldn’t come off as easily as you have said. Also, prior to painting did you wash the walls to remove any oil or other material? If the walls are not really oil free you won’t get good adhesion of the paint. Let the paint dry a couple of days before you do your mortaring.
I take a much different approach. I spray my brick walls with the mortar color (usually a grey primer from Wal-Mart). Once that has dried (overnight) I then dab on the brick color, making sure it doesn’t flow into the mortar lines. It’s almost like dry brushing, but you still leave some paint on your brush. You also might want to look in your latest MR. There’s usually an ad for Robert’s, I think. I have never used it but am tempted to try it. I think you paint your wall the brick color, then once dry you rub this into all the mortar lines. You then use a damp cloth to wipe if off the surface. leaving mortar color in the lines.
I’ve had a lot of the same brick/mortar troubles and letting the paint truly dry is important. I had some luck using plastic wood as mortar. I have taken some and rubbed it into the mortar lines on buildings and what didn’t go into the mortar indentation line was pretty easy to rub/brush away. The plastic wood I had was colored yellow, which dismayed me at first, but looked surprisingly like aged mortar on the finished model. You could also pick out tiny pieces to give this the look of mortar that starting to fall apart a bit. This worked best when the bricks were pretty much finished in terms of painting.
I’ve had a lot of the same brick/mortar troubles and letting the paint truly dry is important. I had some luck using plastic wood as mortar. I have taken some and rubbed it into the mortar lines on buildings and what didn’t go into the mortar indentation line was pretty easy to rub/brush away. The plastic wood I had was colored yellow, which dismayed me at first, but looked surprisingly like aged mortar on the finished model. You could also pick out tiny pieces to give this the look of mortar that starting to fall apart a bit. This worked best when the bricks were pretty much finished in terms of painting.
I don’t use acrylics for painting plastics, particularly if it is going to be rubbed or scraped. I find it comes off too easily.
Too many people are saying that the acrylic craft paints like Apple Barrel and other brands can be used for plastic. Maybe they can. However, they were not made for it. Thus they don’t hold up on plastic very well.
Polly Scale paints are water based and can be used for plastics, but they have to be cured before applying any mechanical forces on the part.
I paint the building either a red primer, then wait a couple of days. Then, I make a wash of rubbing alcohol and acrylic off white or antique white paint (about an 80:20 alcohol/paint mixture). I flow on the wash with the surfaces horizontal. I wait about 24 hours, then rub the walls with a dry rag or paper towel. When the walls are where I want them, I spray the walls with Dullcote.
My early attempts at mortar were frustrated by my attempts to make each mortar line perfect. I was directed to look around at real buildings. I learned that imperfections in our attempts to reproduce something like mortar can look quite good depending on the building being modeled. Buildings in industrial or other extra dirty areas may not look so clean and neat and usually shouldn’t. And don’t forget the 3 foot rule. Apply your paint, weathering, etc. and stand back to judge how it looks in the process.
On rubbing off paint using the plastic wood - rubbing may be too strong a word to describe what I did. If the wood filler is fresh and moist, you’re really just wiping it on to fill the mortar lines and then wiping off excess after a minute or two. I wouldn’t say this is for every building because the color of the filler may not be a good match for how the bricks are painted and weathered.
I have been painting exclusively with acrylics for years because I don’t like the solvents needed to use enamels. I have had excellent results.
I attended a train show last year where a woman was demonstrating paint techniques. She was using acrylics, with terrific results.
Here was her technique, in a nutshell, with lesson learned from my own experience.
Wash the plastic pieces thoroughly in dishwashing detergent and allow to air dry. From this point on, use cotton or latex globes to handle the pieces from here on out.
Prime the plastic and allow it to dry for 72 hours.
Apply your acrylic base coat (brick color). Use a color that is darker than the desired final color. Allow to dry for 72 hours. Acrylic is a polymer, and the paint bonds well to itself. If you apply pressure to the paint before it has cured fully, it will peel.
Apply a thinned wash of the mortar color (she used concrete). 1 part paint to 8 parts thinner was her formula. She used 70% rubbing alcohol to thin. Then pass an absorbent cloth or shop towel across the surface of the model. Use just enough pressure to keep the cloth on the surface without forcing it down into the cracks. This takes some practice to get right. I could not do it the first couple of times I tried without wiping all the wash away. Traces of the mortar color will remain on the bricks, and that’s ok – it looks like real brick. Don’t sweat it if you wipe too much off… just let the wash dry (a couple of hours) and repeat.
Let dry 24 hours. Then apply a very thin black wash sparingly over the whole thing.
I nuke my models for about 30 seconds to cure the paints. I started doing that about 20 years ago and I’ve never once had any problems with paint curing, adhesion or peeling over time.
For brick mortar I’ve always used either a wash of mortar colored paint, or used spackling compound rubbed into the brick. Either way I’ve gotten decent results.
Hello CTValley, (I’m sorry but I don’t know your name), I would like to have additionnal infos regarding your reply to my post.
You stated that you “prime” the plastic; what colour do you use and is it an acrylic paint?
You also mentionned at the end you apply a “thin black wash”, can you please give me your reciepy?
Thank you everybody once again for your generous informations, you don’t know how much this helps me.
Today I tried applying the mortar after giving the brick colour a dull coat, once again I messed it up and I scrubbed the parts to their original colour.
It’s common to use avatar names on here; don’t worry about it. If it makes you more comfortable, my name is Ben (my wife often calls me Jackass, but we’ll leave that off the forums [:)]).
To answer your question, I use Testors spray primer in either white (if the overlying color will be light) or gray (if the overlying color will be dark). I’m not sure what the woman at the train show was using. The parts had been primed a week before the show. It was white, though, whatever it was. I’d use the gray for brick. I’m not actually sure whether this is classified as an enamel or not. It’s stocked with the enamel spray paints in the LHS, but it doesn’t say “enamel” (or acrylic, for that matter) on the primer can.
My black wash is 1 part paint to 12 parts thinner. You don’t need a lot of this, just enough to flow down into the cracks and make the detail pop.
I like the idea of nuking (microwaving, for our friends for whom the American vernacular isn’t their specialty) your parts to cure them. I’ve never tried that, but it should work. You just want to be careful with the time and power settings.
And I just thought of something else, too. Are you airbrushing or brush painting? If the former, you may be spraying from too far away, allowing the paint to dry too much before it hits the model, thus reducing its adhesive capabilities.
