Jump to content
 

Dirty fingers: Trial and error with bricks and mortar


Mikkel

1,088 views

Here are some illustrated notes from experiments with brick- and mortar-colouring for my 4mm scale station building. Please note that these are just my own bumbling exercises. There are no silver bullets here.

 

Method 1: Flood & Wait
 

001.jpg.5be3dd50b8c9cac688d342fbb4b9480d.jpg

 

So far, my standard method has been the well-known "flooding" method. I paint the brick sheets dark red (Vallejo 70.814 Burnt Red)…

 

 

002.jpg.2588f0916bcaa866a441813dabcbc4b0.jpg

 

… then when dry flood the sheet with a milky white wash (Vallejo 70.918 Ivory). This is then left to dry.

 

 

003.jpg.e28f8c9ee2d977ff123ac40fd834942b.jpg

 

Sometimes I’m happy with the result, as on my stable block above.

 

 

004.jpg.1ef78ab7117fec3bd3f5294df5fc2dc0.jpg 
But at other times it comes out messy, like here. These are SEF brick sheets. I find that the method works best with Slaters sheets which have more sharply defined mortar courses. But my Silhouette cutter doesn’t like them, so I'm stuck with the SEF sheets.

 

 

Method 2: Wipe & Go

 

005.jpg.1ea394847d2f3e42f5441526a1381149.jpg

 

Looking for more control of the results, I tried another time-honoured method - i.e. painting a brick sheet, then wiping off the paint with a finger. This leaves paint in the mortar courses. Not a bad result for a quick effort, though it only adds colour, not texture.

 

 

006.jpg.2a79c942a009ef5f5fbf3ccb73b860ef.jpg

 

Another attempt with the same method, using a darker paint for a different look. I know most people use a cloth or sponge to do the wiping, but in my view nothing beats the subtleness of a finger.
 

 

007.jpg.7d88697367094acd4f405106a964714d.jpg


Lovely mess! I’ve always liked Phil Parker’s credit to “painty hands” in his blog tagline. I agree, it makes you feel alive 🙂

 

 

Method 3: Polyfilla Pointing

 

Turning to another method, I looked at @GWR57xx's lovely 7mm coaling stage, where the mortar is done with filler, using the technique described by @47606odin in this useful video:

 

 

 

008.jpg.8a861e1f6588d6974a8a5135a92f50e8.jpg

 

I have only seen the filler method used on 7mm scale laser cut structures, but decided to try them on 4mm embossed plastic sheets.

 

 

009.jpg.74d9f0db478f2d0a3dc2f60d355c7712.jpg

 

I first tried rubbing lightweight Polyfilla directly onto an unpainted SEF sheet. Decent result, though the Polyfilla fills up the mortar courses almost too efficiently.

 

 

010.jpg.d2cb93d4730a3f918f9bcc9d05562a27.jpg
 
I then tried it on painted test pieces. Here the Polyfilla absorbed some of the paint, turning pink. The paint had dried for 24 hours, maybe longer is needed. And I see that @GWR57xx used Halfords spray paint, which I think is enamel. I used Vallejo Acrylics, maybe that’s the problem.

 

 

011.jpg.1d5bd584dce0243861d49001070f2973.jpg

 
I also had challenges with the Polyfilla acting as a kind of abrasive when I wiped it on, removing the base colour (right). But these could just be teething problems, I may revisit this method later.

 

 

Method 4: Paint & Pigment
 

012.jpg.4079eadd9d0ee66be3e89bbc670066f2.jpg

 

The Polyfilla method gave me an idea for an alternative approach. I painted a piece of SEF brick sheet… 

 

 

013.jpg.9d29848215711182b1fbe9908b4c0861.jpg 
…and immediately stippled on MIG modelling pigment (Sinai Dust ref A. MIG-3023) while the paint was still wet.

 

 

014.jpg.77ef721dfebc0741fa7ca0851556703f.jpg

 
I then quickly brushed most of it off again with a brush. The remaining pigment sticks to the wet paint.

 

 

015.jpg.6fde0ac8aa2d768e31f2d4410870fbfc.jpg

 
Finally I used a damp (not wet) finger to remove the pigment on top of the bricks. I found that a “prodding” motion worked best, along with an occasional diagonal wipe. The things we learn!

 

 

016.jpg.50e18ca881a8c694fc7bd1a5f5ec7c22.jpg

 

I like the matt texture and slightly uneven look left by the pigment. The mortar courses are overscale, but that seems to be the case on most brick sheets.

 


 

 

 

018.jpg.de47b4c839826f1f3fe7569a3e153bc2.jpg


Here is the Paint & Pigment method used on Slater's brick sheets. Incidentally, comparing this photo to the previous one highlights the differences between Slater's and SEF sheets (different bonds notwithstanding). The Slater's bricks are more sharply defined.

 

 

017.jpg.e36f859869050b4929ea638e3090b03a.jpg


The surplus pigment is not wasted, I worked on a newspaper so most of it was re-used.

 

 

018.jpg.f1b6c9d93d554df0a6101c952063b27f.jpg


The method does have issues. The pigment transforms the shade of paint, so I had to experiment carefully with different colours first, as above. The outcome is also affected by the thickness of the paint, the relative mix of paint and pigment, and how quickly the pigment is brushed off! The type of pigment used also matters, e.g. Humbrol powders didn’t work.

 

 

020.jpg.5e818ad4b69372638ee504effafa1b32.jpg

 

So I had to go through a good deal of trial and error with this method. On larger surfaces like those above I found that I had to work quickly, or the paint would dry before the pigment came on.

 

 021.jpg.e9c09e6b68270c1a7f6dce0594a5f612.jpg

 

I liked the results though, and eventually ended up using it on my station building, as seen here.  

 

 

022.jpg.f79f3e3576d747ebfbb71d2d54091d30.jpg

 
I’m modelling my station in newly built condition so I assume the bricks and mortar should be fairly clean. Although I’m not quite sure what happens to the colour of mortar as it ages?

 

 

023.jpg.cbb11ded8ad5d4d3fdb96398c228cef1.jpg


In any case, a bit of weathering may be in order. I’m currently experimenting with that. I revisited the old trick of rubbing a colouring pencil diagonally across the sheet. A very soft pencil seems to be vital, or it will rub off the paint.
 

 

024.jpg.1517d09937ee4d008e84c733dbf2fdb6.jpg


I got better results with very careful dry-brushing using a dark brown colour. I think I’ll try a bit of that on my station building.

 

 

025.jpg.62514a7023d2741bc40630da2f67de95.jpg

 
So that’s where I am at currently. The “paint and pigment” approach has worked out OK on my station building, but it involves various variables that can go wrong. I’d like to find a method with fewer risks and more control. Or maybe what I really need is a therapist 😊

 

 

Edited by Mikkel

  • Like 26
  • Agree 1
  • Informative/Useful 9
  • Interesting/Thought-provoking 4
  • Craftsmanship/clever 14
  • Round of applause 1

21 Comments


Recommended Comments

mullie

Posted (edited)

I've heard Polyfilla works well on Wills sheets where the mortar course is deeper though I haven't tried it as theses days I mainly use Slaters plasticard. I think I have tried most of the techniques you have tried and had many of the problems.

 

I think current favourite is a coat of matt grey primer to start off with, often from a rattle can, then lightly sand the brick work to remove paint from the brick faces which also adds texture. I then dry brush a variety of colours, usually using artists acrylics and talc for matting effect.

 

The new station building is looking excellent .

 

Always good to see a new post.

 

Martyn

Edited by mullie
  • Like 2
  • Agree 1
  • Informative/Useful 1
  • Interesting/Thought-provoking 2
Link to comment
  • RMweb Gold

The late great Allan Downes was an advocate of the polyfilla method albeit on the thicker Wills sheets 

  • Like 3
  • Informative/Useful 2
  • Interesting/Thought-provoking 1
Link to comment
  • RMweb Gold

@Mikkel, thanks for the compliment 🙂. I must get on and finish it, but I keep getting distracted…

As it happens, I’ve spent the past couple of days 3d printing test piece walls to determine the optimum size for brick spacing and mortar depth to give the best result for the polyfilla method. It works well for me in 7mm, but probably needs larger gaps than 4mm can provide to give a realistic result.

I’m finding that the 3d resin printed walls need wider and deeper gaps than laser cut ply, mdf or card, probably because with the latter the paint is at least partially absorbed by the material, leaving space in the mortar course, whereas in the former the paint sits on the surface of the resin and closes the gap, which therefore needs to be bigger to start with.

I also found that it is necessary to give the base colour time to fully harden and also give it a coat of Matt varnish to seal it before applying the filler, otherwise the colour can bleed into the mortar.

I’m very impressed by your station building, as I have been by all your other Farthing builds. It is modelling like yours that has inspired me to want more from my own modelling. Thank you.

  • Informative/Useful 5
Link to comment
  • RMweb Gold
Mikkel

Posted (edited)

10 hours ago, mullie said:

I've heard Polyfilla works well on Wills sheets where the mortar course is deeper though I haven't tried it as theses days I mainly use Slaters plasticard. I think I have tried most of the techniques you have tried and had many of the problems.

 

I think current favourite is a coat of matt grey primer to start off with, often from a rattle can, then lightly sand the brick work to remove paint from the brick faces which also adds texture. I then dry brush a variety of colours, usually using artists acrylics and talc for matting effect.

 

The new station building is looking excellent .

 

Always good to see a new post.

 

Martyn

 

Thanks Martyn, very useful. I really like the textured structures on your Upbech St Mary, so will have a play with those tips. And I have some Wills sheets kicking around, will try the Polyfilla method on them. I find them difficult to work with, but one or two of their pre-cut kits are attractive.

 

The depth of mortar courses does seem to make quite a difference to what works best. Which isn't made easier by the fact that sometimes that depth varies even within the same sheet, as I've found in some cases!

 

 

10 hours ago, gwrrob said:

The late great Allan Downes was an advocate of the polyfilla method albeit on the thicker Wills sheets 

 

Thanks Rob, I didn't know that he used this method. BTW I recently discovered that Allan's website is still in place. Mostly stone built structures on there, but I found a video of some of his brick-built structures. Extraordinary as always.

 

 

 

8 hours ago, GWR57xx said:

@Mikkel, thanks for the compliment 🙂. I must get on and finish it, but I keep getting distracted…

As it happens, I’ve spent the past couple of days 3d printing test piece walls to determine the optimum size for brick spacing and mortar depth to give the best result for the polyfilla method. It works well for me in 7mm, but probably needs larger gaps than 4mm can provide to give a realistic result.

I’m finding that the 3d resin printed walls need wider and deeper gaps than laser cut ply, mdf or card, probably because with the latter the paint is at least partially absorbed by the material, leaving space in the mortar course, whereas in the former the paint sits on the surface of the resin and closes the gap, which therefore needs to be bigger to start with.

I also found that it is necessary to give the base colour time to fully harden and also give it a coat of Matt varnish to seal it before applying the filler, otherwise the colour can bleed into the mortar.

I’m very impressed by your station building, as I have been by all your other Farthing builds. It is modelling like yours that has inspired me to want more from my own modelling. Thank you.

 

Thank you, also for the insights! I would be happy if I could achieve the mortar courses on your coaling stage, and  look forward to seeing your 3D printed walls. 

 

It's interesting that the paint is absorbed by the ply/mdf/card, I had not considered that. So we have to consider the nature of the material as well, along with the width and depth of the mortar courses, the "filling" used for the pointing (paint, filler, other), the priming and base coat, the timing of it all, etc. No wonder results vary. 

 

 

Edited by Mikkel
  • Like 5
Link to comment

Thank you for sharing Mikkel. Some very useful hints and tips and I also rather like your 'paint and pigment' method. Many things and techniques to learn before rushing into Bath Stone region. I continue to watch and be inspired Sir.

  • Like 1
  • Thanks 1
Link to comment
  • RMweb Gold

Glad if it's of use Matt. I'm sure stone-built structures have their own particular challenges, I haven't worked much with that. Looking forward to what you come up with. 

  • Like 1
Link to comment
  • RMweb Gold
GWR57xx

Posted (edited)

6 hours ago, Mikkel said:

Thank you, also for the insights! I would be happy if I could achieve the mortar courses on your coaling stage, and  look forward to seeing your 3D printed walls. 

 

Kind of you to say Mikkel, but I'm still fumbling my way along picking up gems of advice from the really good modellers here...

 

These are the latest test pieces I've been experimenting with:

DSC05808.JPG.cc7ac5996776de0511ca8b370f6e3529.JPG

 

The two pieces on the right are laser cut card, one of which was sealed with Mod Podge before painting & filling (just to see what, if any, benefit it gave).

On the left are my first three trial 3d printed pieces. These are U shaped, intended to wrap around the base of a buttress. The top course is chamfered.

Top was a test to see if the wall could be printed face down on the build plate (for speed). Answer a resounding NO as the "elephants foot" has completely obliterated the brick detail.

Middle: as my laser's kerf is approximately 0.2mm, this piece also has 0.2mm gaps between bricks. Hardly any filler has stayed in the gaps. The photo makes it look better than it is because of the very low sun producing nice shadows.

Bottom: a test with different gap widths. Starting at the top row of chamfered bricks, left to right two bricks at a time the gaps are 0.3; 0.4; 0.5; 0.6 & 0.7mm. Then below that, top to bottom two courses at a time the same sequence of gaps. From this I picked 0.4mm as the gap to use on the next test piece.

 

DSC05809.JPG.c2ba4524d82929a7c7a5fcf9a269de9e.JPG

 

I printed two copies, the lower one having a small amount of texture applied to the surface of the bricks. It is not very noticeable though, so probably not worth the effort.

These are prior to applying the filler, to show that I haven't flooded the gaps with paint but neither have I worried too much about getting some paint in them.

 

DSC05810.JPG.0fc6f18637e0f46906afe5c7f04357d3.JPG

 

The filler has been freshly applied here. I'll leave it to fully dry and set then give it a brush over to clean the excess off the brick faces, but I think it compares quite well with the mortar on the laser cut pieces.

 

Edited by GWR57xx
  • Like 8
  • Craftsmanship/clever 4
Link to comment
  • RMweb Gold
Quote

And I see that @GWR57xx used Halfords spray paint, which I think is enamel. I used Vallejo Acrylics, maybe that’s the problem.

 

Mikkel, Halfords paint is actually acrylic, though the key difference is that it is a solvent based one (I have yet to find a suitable solvent to dilute decanted paint and soon gave up on the idea). I'm thus guessing it's down to Vallejo being water based (right lines of thinking, just a subtle difference).

  • Informative/Useful 3
Link to comment
  • RMweb Gold

Mikkel and GWR57xx,

@Simond suggested using polyfiller on my stone walls, but I was concerned that he had used it in 0 gauge and I was not sure the mortar gaps would be big enough in 00.  Thank you, I think I have my answer.  If I did the sort of experimenting that you have done I am not sure I would finish anything.  (Now, now, I have finished at least one model, I think).

 

As to the milky thickness of paint to fill the mortar, I have used that successfully on the Ratio station kit of ?Corfe Castle, but the gaps between the stones was huge so I was surprised how well it did on your trial.

  • Like 3
Link to comment
  • RMweb Gold
Mikkel

Posted (edited)

18 hours ago, GWR57xx said:

 

Kind of you to say Mikkel, but I'm still fumbling my way along picking up gems of advice from the really good modellers here...

 

These are the latest test pieces I've been experimenting with:

DSC05808.JPG.cc7ac5996776de0511ca8b370f6e3529.JPG

 

The two pieces on the right are laser cut card, one of which was sealed with Mod Podge before painting & filling (just to see what, if any, benefit it gave).

On the left are my first three trial 3d printed pieces. These are U shaped, intended to wrap around the base of a buttress. The top course is chamfered.

Top was a test to see if the wall could be printed face down on the build plate (for speed). Answer a resounding NO as the "elephants foot" has completely obliterated the brick detail.

Middle: as my laser's kerf is approximately 0.2mm, this piece also has 0.2mm gaps between bricks. Hardly any filler has stayed in the gaps. The photo makes it look better than it is because of the very low sun producing nice shadows.

Bottom: a test with different gap widths. Starting at the top row of chamfered bricks, left to right two bricks at a time the gaps are 0.3; 0.4; 0.5; 0.6 & 0.7mm. Then below that, top to bottom two courses at a time the same sequence of gaps. From this I picked 0.4mm as the gap to use on the next test piece.

 

DSC05809.JPG.c2ba4524d82929a7c7a5fcf9a269de9e.JPG

 

I printed two copies, the lower one having a small amount of texture applied to the surface of the bricks. It is not very noticeable though, so probably not worth the effort.

These are prior to applying the filler, to show that I haven't flooded the gaps with paint but neither have I worried too much about getting some paint in them.

 

DSC05810.JPG.0fc6f18637e0f46906afe5c7f04357d3.JPG

 

The filler has been freshly applied here. I'll leave it to fully dry and set then give it a brush over to clean the excess off the brick faces, but I think it compares quite well with the mortar on the laser cut pieces.

 

 

Very impressive results! Thanks for sharing them. Your experiments may also interest @David Bigcheeseplant who is 3D printing Princes Risborough station (although in 4mm scale, which of course is a different kettle of fish in this respect). The 3D printed pieces do look good. I can see why you experimented with texture on the 3D prints, I like the textured look of the lasercut pieces.

 

You mention that the 3D printed piece in the first shot looks better than it is, and that little filler stayed in the gaps. What I find interesting though is that it looks quite similar to the (Edwardian) brickwork at e.g. Newbury.

 

P1040411.jpg.8dea1f998535a6637984b05ca8d97f89.jpg

 

Which makes me wonder whether we sometimes exaggerate the visual impact of mortar courses on models - especially 4mm ones. I may have mentioned it before, but when I look closely at this great model on Jim Smith-Wrights New Street (built from SEF sheets by the the way), I'm not sure he has applied any pointing at all. Yet I think the model works very well.

 

It does, of course, depend on the style of pointing on the prototype. Here's a photo of the (sadly closed) pub just above Newbury station. A very different look compared to the station.

 

P1040442(2).jpg.0017a01ed1f7189a9e45953129c19ada.jpg

 

 

Edited by Mikkel
  • Like 6
Link to comment
  • RMweb Gold
14 hours ago, 57xx said:

Mikkel, Halfords paint is actually acrylic, though the key difference is that it is a solvent based one (I have yet to find a suitable solvent to dilute decanted paint and soon gave up on the idea). I'm thus guessing it's down to Vallejo being water based (right lines of thinking, just a subtle difference).

 

Ah, thanks for clarifying that. I've always been curious to try out the Halford's range as they seem to give very good results. We can't get them here though. So I suppose it will have to go on my shopping list next time I cross (under!) the channel.

 

13 hours ago, ChrisN said:

Mikkel and GWR57xx,

@Simond suggested using polyfiller on my stone walls, but I was concerned that he had used it in 0 gauge and I was not sure the mortar gaps would be big enough in 00.  Thank you, I think I have my answer.  If I did the sort of experimenting that you have done I am not sure I would finish anything.  (Now, now, I have finished at least one model, I think).

 

As to the milky thickness of paint to fill the mortar, I have used that successfully on the Ratio station kit of ?Corfe Castle, but the gaps between the stones was huge so I was surprised how well it did on your trial.

 

Chris, I can't remember what sheets you used on Traeth Mawr, but it seems the Polyfilla results partly depend on that. Maybe you have some off-cuts to try it on? 

 

 

  • Like 1
Link to comment
  • RMweb Gold
4 hours ago, Mikkel said:

 

Ah, thanks for clarifying that. I've always been curious to try out the Halford's range as they seem to give very good results. We can't get them here though. So I suppose it will have to go on my shopping list next time I cross (under!) the channel.

 

 

Chris, I can't remember what sheets you used on Traeth Mawr, but it seems the Polyfilla results partly depend on that. Maybe you have some off-cuts to try it on? 

 

 

 

Mikkel,

I have used Slaters, random stone, so the mortar lines are not very deep between the stones.  On the platform facings it is SEF and the mortar lines are deeper.  They might be better for the polyfiller method.

 

Mortar.  I think older mortars were more grey than white, especially with time, but as you say it depends on the building.  Most houses around here are 40-50 years old and have red bricks with distinctive yellow mortar, but the ones over the back to us have much paler bricks with a dark mortar.  Photos of your buildings are always helpful, but the bricks and mortars will have aged and, depending on where the building is the air quality will have changed.  Since the smokeless zones came in during the sixties many buildings in cities have been cleaned up, and even where they have not been they would have been cleaned by the rain,  (I always thought that the Natural History Museum was a dirty brown colour naturally, until it was cleaned and exposed the beautiful multicoloured stone work.

  • Like 1
  • Informative/Useful 2
Link to comment
  • RMweb Gold

Interesting. So when it comes to stone sheets SEF have deeper mortar courses than Slaters? On my brick sheets it's the other way round. In other words, no universal rules can be applied.

 

Regarding mortar. I have been wondering whether and how much it darkens over time naturally. I have not noticed it in houses I have lived in or known - but that is also a short timeframe. Newbury station is now 114 years old. And then there is the environmental effect that you mention.

 

And then of course the effect of repair work and modifications. Here is one end of Newbury station. Quite a lot of stuff going on here, brick and mortar-wise:

 

P1040416(1).jpg.0bddcb864b0bfb43c5cbbca22aa3d238.jpg

 

 

P1040416(2).jpg.6afbb837edf3863c9e2966e1eafaa25e.jpg

  • Like 7
Link to comment
  • RMweb Gold

Not a lot of relief there, and thin mortar lines. An argument for brick paper. In fact, it looks like brick paper!

  • Like 1
  • Agree 4
Link to comment

Nice work, but don't forget that mortar was sometimes tinted and rather than having darkened with age, it started out that colour.

  • Like 2
  • Agree 1
  • Informative/Useful 1
Link to comment
  • RMweb Premium

Nothing to show you now, and talking small sizes of buildings in 0 scale, but in the past I’ve painted embossed plastic sheets for bricks or stonework by an overall wash, using Humbrol flat paints, maybe patchy dabs of slightly different tone. Then do a paint mix for mortar and load a sprinbow pen, going along all the courses and risers by hand. This is tedious, but the courses aren’t as prominent as when you’re flooding and wiping.

 

p.s. There’s always doing this, which looks great for old buildings:

 

https://www.westernthunder.co.uk/threads/old-parrock.6209/page-5#post-172805

 

 

Edited by Northroader
  • Like 3
  • Informative/Useful 1
Link to comment
  • RMweb Gold

That's an interesting method with the springbow pen, hadn't heard of that before. Thank you.

 

The Pendon method in the link gives a lovely result. I believe it is also the approach Stephen Williams used on his stone-built Faringdon structures, as seen in his GW Branchline Modelling books. 

 

P1050183.JPG.b4dbc903bbf298d963956c7afb38e804.JPG

 

 

  • Like 3
Link to comment
  • RMweb Premium

Excellent master class as per usual.  Like the paint and pigment method out of all your experimentation too.  Assuming that the SEF sheet is the lower one in that picture I prefer it to the top one even though you say the Slater’s brick is better defined - it just looks like the mortar is more realistically sized to me.  

  • Like 1
  • Thanks 1
  • Interesting/Thought-provoking 1
Link to comment
  • RMweb Gold

Thanks Mike, interesting thoughts on the SEF vs Slater's sheets. In my view the both suffer from overscale mortar courses. Not sure why really, perhaps it's easier to print - or maybe it's like figures where heads have traditionally been modelled larger than they are because we expect the features to be clearly visible.

 

 

 

  • Like 1
  • Interesting/Thought-provoking 1
Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...