Stucco Texture in HO

[DaKra]

Last year I struggled to make a stucco wall section on a diorama, it took a full day of experimenting with various methods before I basically gave up.   I resorted to "cheating" by lasering a photo of stucco texture onto a gesso prepped plywood panel.  It came out great, but it bothered me that I didn't have a hand-applied method I could include as part of the finishing instructions in a kit.  So here is something I'm working on now, which I think looks just as good.   I'm interested in learning any other methods. 

The model is a 1920s era filling station.  Many of these humble structures were designed with a jaunty style and make very interesting models.   This one will go in a NYC urban scene and provide an interesting contrast with the brick tenements. 

Here is the naked plywood base. 

[DaKra]

Step 1  is mix up a slurry of Durhams Water Putty, acrylic paint and water.   By volume I mixed about 1 part paint, 1 part putty and about 1 part water.  Its not critical but it should have the consistency of butter milk or pancake batter.  This gets brushed on the model, being careful to avoid building up thick fillets under details.           

[DaKra]

I applied two coats, waiting to dry, then sanding in between.  If I were working in 1/48 scale, or larger, this might be the only step.  But HO requires finesse to keep things in correct scale and proportion.  Also its important to consider the prototype.  Stucco comes in many forms.   If I were building a medieval half timber house for a WW2 ETO diorama, in 1/35 I would try to achieve a coarse, heavily weathered look.  But this gas station was coated in a decorative stucco, and since the diorama is set in the 1930s, it will show no more than 15 years of age.  It should not be very coarse. 

So this application gets sanded down.  Basically its going to serve only as a grain filler that provides a subtly wavy and uneven surface for the final texture and paint.  A fiber paint sanding pad makes short work of this.   

[DaKra]

Now two coats of automotive primer go on.   I used Krylon.  For most of my scale model purposes, this stuff is too thick.  I set it aside as useless, until I thought of this.   

The first coat goes on smooth and will serve as a filler for any small scratches left behind by the sanding.   So now I have a smooth but subtly uneven surface, it just lacks a little surface texture.     

So after its sort of dry, like 5 minutes, I hit it again with the primer, but I sprayed it on "wrong".   Instead of holding it the proper distance, I held it back a little over two feet, like a noob does, and ended up with that sandpaper finish that looks terrible on everything.  But perfect for this. 

All for now.  Next I will paint and weather.       

Dave

[eTraxx]

Bravo! Excellent thread. I've used the 'noob' technique for a slight texture for rust.

[Mobilgas]

Dave,    I like the effect for HO didn't cover up the detail on the building......don't look to thick. Being a gas station nut I'm curious as what brand gas will this station be selling?    Craig

[DaKra]

Funny you should ask that Craig, as I don't really know for sure what brand gas station this was.   The prototype photo I'm working from doesn't show the brand, and was taken after it stopped selling gas.   I'll probably make it a Texaco, but I've drawn up decals for other brands.  Shell might be nice, too.   

Dave

[chester]

Interesting technique that seems to work well Dave. Nice results. If you're looking for what others do, I have used a product called Durabond used in drywall finishing. It is a powder that comes in different setting times. (i.e. Durabond 90 takes 90 mins. to cure) It is a lot harder than premixed drywall compound yet easily sanded.

[Ray Dunakin]

Very nice, a good subtle effect!

BTW, does anyone know if that water putty holds up outdoors?

[eTraxx]

It's a gypsum-based filler. The product page says .. "DURHAM'S Putty will withstand weather if kept painted, but paint will peel from damp Water Putty."  .. which I take to mean .. no. You could prob find something at Lowes .. one of the cement products that might work for outside

[finescalerr]

As you were describing the technique, Dave, I was thinking, "Why not spray a coat from too far away?" And then, in the next photo, you described exactly that. HO is a tricky scale for achieving subtle effects and you once again have managed it well. -- Russ

[Malachi Constant]

Nice mix of techniques to get the subtle texture in the small scale!

Cheers,
Dallas

[DaKra]

On the waterproofing, I'd figure if you use Durhams as an additive to a weather proof paint, like an enamel, it won't absorb moisture and cause problems.   I think the stuff that Chester mentioned would work, too, maybe better.   In this case, the material only needs to fill the basic function of a filler to thicken and roughen the paint.   

Durham's is great for a lot of things.  I first heard of it in FineScale Modeler's series on boxed dioramas by Ray Anderson.  He used it very effectively for rocks, masonry, etc.   The series of articles was reprinted in a booklet 

http://www.amazon.com/Art-Diorama-Ray-Anderson/dp/0890240922

Dave

[DaKra]

Now that I have the texture, I need to apply the finish.   I like to brush paint acrylics because I can use thin layers of paint to get nice, natural looking tone variations.   

White acrylic is often problematic because it doesn't have good coverage unless its thick.  But thinning it down makes it easy to lift a previous coat with the next one.   So I was careful to let each layer dry in between, and apply the next layer fast and light.  I stopped at three coats.  Didn't want to obliterate the stucco texture.   

That was followed up by a coat of Future, clear acrylic so that I'd have a good surface for an oil wash. 

[DaKra]

Next step was an oil wash to add some grime and also enhance the texture and the shadows under the trim work.   Have to be really careful with effects like this or it starts to look unnatural.     It will be placed in a city environment so I can justify a lot of grime but still, can't overdo!   

I used highly thinned out W&N Paynes Grey based on the experiment I documented in the other thread.  This pigment is very finely ground so it doesn't clump.  I neutralized the blue tint with a speck of burnt umber.     The Future coat helped it flow and kept it from staining the white paint.

I guess I could have used an airbrush and an undercoat, the way the model aircraft guys enhance their panel lines.  Probably faster and simpler.     

That's all for now.  Next I will dry brush a little white here and there to reduce the grey cast added by the wash.  Dry brushing is another of those areas where less is more, or it will start to look phony!