Weathering cement hopper - suggestions please

[GaryHinshaw]

I'm working on upgrading and weathering a set of cement hoppers and I'm interested in capturing some of the cement grunge that often accumulates around the loading hatches on the roofs of these cars.  Here is an example:

http://www.railcarphotos.com/PhotoDetails.php?PhotoID=30659

and here is my first attempt on a model (on the right - click for a larger version):



I'm having a hard time getting a photo that really shows what I want to illustrate, so that one will have to do.  I'm not displeased with the effect, but I'm looking for suggestions of other techniques to try.  The method here was to use mix a bit of dry Smooth-It (fine plaster from Woodland Scenics) with some light & dark grey Bragdon powders, wet the affected area on the car with washer fluid, then work in some dry mix with a brush and let harden.  I think the material is pretty good, but I wouldn't mind a bit more control over the application of it.  Maybe a spatula or very fine sponge cosmetic sponge?

As an aside, I find that weathering jobs that look good under bright workbench lighting (and magnification) can often look overdone in more typical layout room lighting.  As an example of how much difference lighting can make, here is another similar view with an incandescent fill light added (but somewhat fainter ambient light than above).  The redder tones sure highlights different aspects of the weathering.



If you have any cement examples you like, please show and tell!

-gfh

[Bendtracker1]

Gary what about mixing up a small batch on a palette, then using a small stiff brush, apply it by stippling it on the surface around the hatches?
Might need to damped the area a bit to get the mix to bond to the surface?
Just a thought...

[tom mann]

Natural Grey unsanded grout.   Probably makes a good wash too if overly thinned.

[ednadolski]

This looks like it wants a multi-layer approach.  I'm not too sure about plaster, but I would probably start with paints and powders.  Stipple on a layer, remove a bit with a dampened brush or cosmetic sponge, dust on the powder, spray with a sealer.   Repeat, letting the areas 'grow' with subsequent layers (and varying the colors).   I've seen some interesting results on the old MTW using hairspray as a sealer between layers (but unfortunately those pages are long gone...  )

IIRC it was in MR a while back, someone weathered cement hoppers using small amounts of the finely powdered anchor bolt cement (mixed with thinned Dullcote, but likely any clear coat would work).  However that was HO, so I am not sure how well it scales down to N.   I'll look that up and see if I can find anything of further interest.

In any case it would probably be easier to apply and to obtain better results if you (gently) remove the roofwalks.  That choice will probably depend on how many cars you want to do, and how much time you want to invest.


Ed

[GaryHinshaw]

Thanks for the tips.  I have plenty more samples waiting in the wings, so I'll report back.

I did recall a Mont Switzer article on this topic in MR a while back (Mar 2009 according to the index) but I tossed all my pre-2010 copies when I moved...

[wazzou]

In old experiments, I carefully brushed on a thin layer of Testors Dullcote, from the bottles, if they are still available and loaded a thick bristled brush with AIM weathering powder and tapped the brush so the powder would fall on to the wet Dullcote.

[John]

white powdered chalk mixed into dullcote

[Philip H]

I've got some Arizona Rock and Mineral "earth" at home that is a sort of faded yellow color and very powdery. I could see dusting some of that into wet Dulcoat for a 3d effect.

[BCR 570]

If you have any cement examples you like, please show and tell!

-gfh

Lime service car - close enough?

Tim

[GaryHinshaw]

Nice Tim.  Got any top shots?

Thanks for all the suggestions.  I have a sacrificial top from an old Trainman hopper to try these out on.

-gfh

[BCR 570]

Nice Tim.  Got any top shots?

Not a closeup top shot, but the only one I have on hand; can take a closer one on the weekend if needed.

Tim