Help weathering concrete

[jcopilot]

I've sprayed-painted a CMR turntable pit with Krylon H2O Niagara Ivory Mist as a base color for concrete.  I thought I could add age and dirt with a wash of some kind, but I haven't been entirely happy with my efforts.

In the October, 2007 issue of MR, Cody Grivno says he used 2 teaspoons of sepia ink in a pint of rubbing alcohol and brushed that over his concrete floors and platforms.  When I tried it on a scrap piece, the color was distinctly rosy pink.

I've tried diluting Ceramcoat paints with a lot of water and the results haven't been entirely satisfactory so far.  Maybe someone has tried this and can tell me the ratio of paint to water (and what colors) to get a better result.

I've found some comments in the Forum about using artist's acrylic paints.  What colors are good?  Are they diluted with water or alcohol?  In what concentration?

So, my question is "What have you used to wash or stain a base coat of paint to represent old, dirty concrete?"

I'm looking for something I can brush on, not apply with an airbrush.

Thanks for your help,

jcopilot

[UP2CSX]

Go to a craft store and get a set of pastel chalks, the more colors the better. Use the blacks, greys, and browns. Shave some each color off in a disposable cup with a dull excato blade to make a dust. Use an old brush and apply to the concrete, changing color combinations until you get one that looks good to you. If you don't like a combination, you can wipe it off with a damp cloth. Once you've got it the way you want it to look, spray it with a coat of Dulcote and you're done.

[simon1966]

Black India Ink diluted in alcohol followed by some weathering powders works for me.

[wjstix]

Ink and paint are great for "wet" weathering (oil, grease, etc.) but for "dry" like coal dust, better to use chalk or the real thing (more or less) - powdered charcoal!! Should be available at a good art supply store near you. I like powdered charcoal because unlike chalk, you can seal it in with flat finish and it doesn't fade or disappear (so you can handle your model without weathering your hands too!!); and unlike paint or ink, if you don't like the result, you can wash it off and start over (at least up until you seal it in with dullcote spray).

 

[Greg H.]

For darking areas I like to rub in some graphite.   This works real well, for making 'cracks' in the concrete stand out. 

[MisterBeasley]

After attending a free clinic at my LHS, I've become a fan of weathering powders, too.  They are ground finer than pre-packaged chalk powder.  I did buy a few packages (oh, that's why free clinics work) and I think they do an excellent job.

Our instructor told us to use Dul-Cote both before and after applying the powders.  The first coat gives the model a good surface for the powder to adhere to, and the second coat keeps the powder there forever.  Dul-Cote also give a nice, flat, non-reflective look to the model, which is part of the appearance of concrete.  The glossy look of most spray paints won't look right, so you need to think of the texture of the surface, too, not just its color.

One of the colors I picked up is an off-white, which looks a lot like concrete dust.

[topcopdoc]

Concrete Color

Concrete has various colors in nature. After much experimenting to get the right concrete color I settled on these two for all my concrete. Delta Ceramcoat Sanstone diluted to your taste with White Ceramcoat for walls and bridges where the elements have had time to work on it.

I use Delta Ceramcoat Mudstone for station platforms, inspection pits, and turntables etc. where oil and dirt have built up over the years. You can dilute with white paint.

A wash on top of these base coats using India Ink or diluted (browns, blacks or grays) paints or caulk should give you the results you want but you have to experiment. The object is to settle on the base coat first and then apply the aging.

Doc

 

[loathar]

That Delta Ceramicoat Sandstone is a great old concrete color. I tried that brown India ink and it came out purple. I like the weathering powders or pastel chalks better. Avoid using the artists charcoal sealer. Works on canvas, but I've had it glaze over on paint. Use Testors or Krylon dull coat.

[jcopilot]

I'll have to pick up some chalks and experiment with them.  As for the 'tooth', I plan to lightly sand the paint with 220 grit to give it a rough surface.  Won't the spray of the Dullcote blow away some/much of the chalk?   How do you minimize that?

The pit is already painted a 'concrete' color and I'm looking for ways to 'age' it.

Would someone who uses artist acrylic paints tell me his methods for weathering?

jcopilot

[MisterBeasley]

  Won't the spray of the Dullcote blow away some/much of the chalk?   How do you minimize that?

I rub the powder in a bit, usually just with my fingers.  (It washes off easily with water.) The Dul-Cote might further "blur" it, but it doesn't blow it off.  I spray it lightly from a distance, so I don't get a powerful jet from the can, more of a lighter misting.

[Dave-the-Train]

Try this thread

http://www.trains.com/trccs/forums/1014520/ShowPost.aspx

and do a search on "concrete"

[PA&ERR]

If you use the pastel chalks for coloring/weathering, make sure you apply make them a little bit darker than you think they need to be. Just about the time you think, "OMG that's too dark" should be about right. The reason for this is that when you "fix" it with dullcoat, the dullcoat tends to lighten up the color a bit.

George

[jcopilot]

Hi All,

Just got back from A.C. Moore with a pack of 24 Artist Pastel chalks with black and a lot of browns and grays.  Picked up a can of Krylon spray matte finish at Wal-Mart (half the price A.C. Moore wanted), so I should be about ready to go.

MisterBeasley suggests spraying first with the matte finish to provide tooth to the surface.  I like that idea better than sanding with 220-grit sandpaper.  Thanks MisterBeasley.

When it comes to scraping the chalk to make the weathering dust, do you find it better to scrape each color into its own cup and mix them later or do you scrape all the colors into one cup?

George suggests applying the chalk until I think it's a little too dark because the matte finish will tone down the colors.  I had read that somewhere before, but had forgotten about it.  Thanks George.

I'll be a few days experimenting with this before I tackle the turntable pit.  Can't wait.

Thanks all,

jcopilot

[jcopilot]

Bump

[UP2CSX]

I'd scrape the colors in separate cups until you get the kind of weathering you want. Just remember to keep a list of what you applied first, second, etc. so you reproduce it again when needed.