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Beginner painting and adding mortar to brick building

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Beginner painting and adding mortar to brick building
Posted by Traincraft199 on Wednesday, April 14, 2021 11:10 AM

Sorry I already have a thread on this but I feel like I need to explain myself better.

I've never painted or weathered a building before. I have an ho scale brick building I want to paint because it's too bright of a red and I want to dull it down. What's the easiest and least likely to go wrong method of doing this? Also, what type/brand of paint should I be looking for/avoiding? I already have an airbrush but I really don't want to permanently mess up my building

I would also like to add mortar to the bricks. I've seen people use plaster, paint, ground up pastels, and even toothpaste. What's the easiest/best way of doing this?

Another thing that confuses me is: Wouldn't painting the building fill in the brick cracks and leave me unable to add mortar?

(edit: should've specified the building is completely unassembled)

Building my first layout, 4x8 contemporary urban area in HO scale 

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Posted by dknelson on Wednesday, April 14, 2021 11:41 AM

Depends on how different a red you want the building to be, and whether it is a completed kit or still in parts.   

It is possible to tone down the color of a raw plastic brick structure without new paint.  If the kit is unbuilt, the late Art Curren (the king of kitbashers) advised vigorous scrubbing with a kitchen cleanser like Ajax or Old Dutch Cleanser - something with a light abrasive in it.  This not only kills the shine but because the surface now reflects light differently, tends to change and lighten the darkness and tone of the color of the plastic.  This might be a different enough look to satisfy you. Depending on what details are on the building this may or may not be practical for a completed kit.

Another thing that can change the look is a coat or two of DullCote. It really does seem to change the color but again that is a function of how light is reflected or absorbed by the surface.   If you have clear "glass" windows however it can be a pain to mask every window.

Another benefit to DullCote is that the surfaces now have some "tooth" making the application of chalks or pastels with darker reds or browns effective, to be sealed with another coat of DullCote (and it may take another iteration before this "takes").

This is more iffy and unpredictable but a misting with a combination of isopropyl alcohol and india ink can make a remarkable change on both painted and unpainted structures (and rolling stock).  And this too gives a surface for chalks or pastels.

There are two or three schools on how best to create a lighter color for the mortar between bricks.  I have tried these and have failed and succeeded with them all!

The first is to paint with a very thin wash of diluted off-white acrylic or latex paint (some guys even use the liquid white shoe coloring meant to revive white canvas "tennis" shoes), and when that paint is almost dry, to wipe off the bricks so lightly that only the paint in the mortar lines remains.  I find that a cloth goes too deeply into the cracks.  A cloth wrapped around a flat block of wood or plastic touches only the top surface of the bricks.

The second is the same as above, but let the white wash dry completely and rub it off the surface of the bricks more vigorously again via mechanical means that involve a hard flat surface and cloth or paper towel, or even a pink pearl type eraser

The third is io paint the structure entirely with an off white, or a white with a touch of the brick color in it.  Let it dry completely.  Then "stamp pad" the brick color on - again perhaps with a cloth or sponge on a hard flat surface so that it does not reach down into the cracks.  Don't overdo the variety of brick colors - sometimes you do see old brick buildings with a very mottled look but in general if you stand far enough away from a brick building it looks quite uniform in shade and tone.

Other modelers have their own techniques. 

There are products, one called Roberts comes to mind, of specific premixed washes for mortar lines.  Looking at a variety of brick buildings one sees quite a bit of variety - sometimes the mortar lines are almost stark white, or off white, but often they are almost the same color as the brick.  It seems like the stark white are more likely to be residential homes where that "look" is part of the intent.

Dave Nelson

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Posted by MisterBeasley on Wednesday, April 14, 2021 12:07 PM

It's always a good idea to ask advice before starting a project you've got little experience with, so good for you.

You'll find a lot of different techniques for these things.  When I build a brick building kit, I usually mask off the edges where the glue will go, because any paint that gets there will interfere with glue adhesion.  Then I spray the outside with brick red or red-brown rattle can primer.  I like those colors for brick structures.  I do this before putting anything together so I can spray the walls flat on the ground to avoid dripping and get a good, even coat.

There are lots of techniques for mortar, too.   I use drywall compound, rubbed into the cracks and then rubbed off when it dries a bit.  To be honest, after trying lots of mortar ideas, I have never found one I'm really happy with.  I usually use a thin wash of black India Ink to tone down the stark raving white of the drywall compound.

I'm an old pfart, 74, so some years ago I bought a magnifying lamp to assist my old eyes.  I use this to paint window sills, door frames and other trim on my brick buildings.  I use a small nothing-fancy brush and cheap acrylic craft paint.  The thing that has made all the difference with my detail painting, though, has been that magnifying lamp.

Who made your building?  Different manufacturers do different things which sometimes require different processes to get them right.

It takes an iron man to play with a toy iron horse. 

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Posted by ctyclsscs on Wednesday, April 14, 2021 3:02 PM

I don't have much to add except two small things since Mr B. and Dave did such a good job.

1. Personally, I don't worry about trying to put "mortar" into every joint. As others have pointed in past threads, when you look at most prototype buildings you see the wall as a whole, not every single brick and mortar joint. Unless it's a very small building and you're very close. I've been fairly happy using powdered grey chaulk rubbed into the mortar lines after painting. Then I wipe off the wall using something that won't remove all of the chaulk. A damp finger seems to work quite well. When it's done it dulls down the wall but you don't really see bright white mortar lines. I think you just need to experiment to see what you like the best. 

2. If you do add some type of mortar, try to wipe it off at an angle diagonal to the bricks so that you don't go into the mortar lines and remove what you just put on.

Hope you'll let us see your results.



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Posted by gmpullman on Wednesday, April 14, 2021 4:53 PM

My early brick buildings were always painted with flat brick-color paints. Recently it occurred to me that when wiping off the excess mortar it would be beneficial to have a glossy surface, basically, youre grouting tile in a miniature sense.

 RH_grout1 by Edmund, on Flickr

This PRR brick signal tower has beautiful brick work but it is one of the ones where I used a flat paint for the brick surface and you can see where some of the mortar has worked its way into the face of the brick.

 IMG_6016_crop by Edmund, on Flickr

Not too bad of a distraction but I'd like a little less mortar on the face. It does give the look of old brick. I usually use tan or beige latex paint for the mortar. 
A few VERY light mists of wet water will cause the mortar to flow into the joint and make wiping off the face a little easier.

Making mortar lines, like ballasting, is a boon for some and a bane for others.

I rather enjoy both.

Good Luck, Ed

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Posted by doctorwayne on Wednesday, April 14, 2021 7:53 PM

...Another thing that confuses me is: Wouldn't painting the building fill in the brick cracks and leave me unable to add mortar?...

If you use your airbrush to do the painting, the mortar lines will not be filled-in.

There's a thread HERE that shows some brick structures and if you scroll down to the second response, there's one technique showing how to add mortar effects to "brick" structures.

Scroll down a little futher for a "how-to" on adding the mortar.  There are other methods, too, but that's the one with which I've had the most success.




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Posted by NVSRR on Wednesday, April 14, 2021 8:14 PM

First.  Toothpaste?   For mortar?   

i use unsanded grout.   Grout pigments allow color tone shifts.  Even. Where repointing was done.   Also.  Some places paint the whole building brick and all.   Usually a medium grey or white.   More modern painted buildings are done with an elastometric polymer coating.  Basically a sealer that is tinted any color.  

i learned from marklinofsweden that takeing bluejean material wrapped around a small wood block works very well for a lot of things like track cleaning.   And here.  Where the material absorbs the paint but is to stiff to flex into the joints.  Works as good to ink pad the paint on if you start with painting the whole building mortar color first.  

recomendation.  Plastruct and others have blank brick sheets. Get a pack of sheets to practice different methods before going to the building.  



A pessimist sees a dark tunnel

An optimist sees the light at the end of the tunnel

A realist sees a frieght train

An engineer sees three idiots standing on the tracks stairing blankly in space

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Posted by Doughless on Thursday, April 15, 2021 8:44 AM

Painting the components before they are assembled, taking care to protect the places it will be glued, allows for mistakes in color to be corrected the easiest way.  Just respray.

Real mortar fills in the gaps in between the bricks, so something like Wayne's method of filling in the cracks with drywall compound probably gives the the most realistic profile.  I have tried his technique and I am unable to master it, specifically where the profile changes dimensions, around window lentls, pilasters, etc. can be a challange for me since I can't keep the application even.  

Many paint the brick color, then go back over it with light gray mortar color to fill in the cracks, then wipe the surface of the bricks to reveal the color.  Working around windows and pilasters to remove the gray paint evenly is also challenging.

- Douglas

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Posted by mobilman44 on Thursday, April 15, 2021 3:18 PM

One of the first methods I've learned has stood the test of time. 

As I used only oil based paints when building structures, I would "paint" the brick surface with a 50/50 wash of the desired mortar color.  Then, resisting temptation, I would let it dry for a day or two.  That may be overkill but it's what I do.

Then, I would custom mix the brick color.  I seemed to always gravitate to a dark red or brown.  Then, using the flat side of a 1/4 inch brush (which has had excess paint removed), I would "drybrush" the brickwork going from top to bottom.  

I have done the process in reverse, and it works well too.  That is to paint all the brickwork the brick color, and let it dry for a day or two.  Then, using a soft flat brush, wipe the mortar wash (50/50 mix) on and let it set for a few minutes.  Then with a clean soft rag, lightly rub the wall in a downward fashion, which will remove the wash from the brick surfaces but leave it alone in the mortar cracks.

Afterwards, with either process, I would apply a spray of dull cote. 

For a newbie (and we all were at one time), I would get a sheet of brickwork and just experiment.  I know I found the results pretty amazing, and I think you will too.  Oh, have to add.....the above methods worked well for me, and they should for you as well.  But, there are obviously other ways to do this, so I would check into them as well.






Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by wjstix on Monday, April 19, 2021 4:35 PM

I use sort of a reverse method I learned from an MR article years back. I spray paint the building with a mortar color - light gray or tan - and then use an art marker to color the bricks. Art markers are fairly stiff, so it only paints the surface, leaving the mortar color intact. You just rub it over the surface, you don't need to like try to color one brick at a time. It only takes a couple of minutes on each wall of the building. You can also leave the areas above and below the windows the mortar color for contrast.

BTW I paint the kit's walls while they're flat (pre-assembly) and paint both sides with the gray or tan color. That helps block the light if you ever light the building, and leaves a good neutral color inside if you decide to add interior details.

(Sorry if link isn't 'live', problem with this computer and the MR site.)



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