Using real dirt on layout

[wdcrvr]

I have seen discussions of using real dirt on layouts instead of buying commercial substitutes.  Some people have made a point of saying they baked the dirt in the oven first and/or ran a magnet over the dirt before using it on the layout.

What is the reason for baking the dirt and how important is it?  Same for the magnet issue?  What are the risks involved in just using the dirt without these preparations?

Also, it seems that sprinkling dirt on your layout and spraying with diluted white glue would just give you muddy white glue.  Doesn't this mixture tend to flake off of the layout?

If you are in favor of real dirt I would like to know why.

If you prefer the commercial substitutes I would like to know why and which ones you prefer.

There must be more to this than I am aware of, but that is why a newbie like me appreciates the wisdom of all the experienced folk that answer these crazy questions.

I am looking to make my scenery as realistic as possible, so tell it to me like it is.

Thanks once again to all of you who show such patience for us new guys.

wdcrvr 

[mlehman]

Two potential issues with Any Old Dirt. Ferrous metals and bugs.

There is a lot of natural dirt that contains enough iron or steel contamination that the magnets that are parts of motors and speakers pick them up off the track -- with bad results.

As for anything that might hatch, crawl, or propagate from your dirt, kill it or be prepared to live with it. You wouldn't knowingly introduce pests into your home, so you sterilize the dirt to makes sure what's dead stays dead and what isn't dead, is.

You always need some sort of wetting agent or the glue or matte medium (my preference) will pool on top of dirt, scenic materials, etc. Use an alcohol mist or a tiny drop of detergent in the adhesive mix to get it to settle.

I use real dirt in a few places because I model the Red Mountain mining district between Silverton and Ouray, Colorado and its color is very distinctive...

But I only use a small amount for this essential purpose where dirt provides the right combination of color and texture compared to everything else on the layout. For instance, most of the color in Red Mountain itself is acrylic paint.

The hobby products are just so much easier to use, more consistent, and no worries about stuff in them. YMMV

 

[joe323]

I do not kow about the muddy white glue.  White glue dries clear or you can buy Elmers clear glue.

The Baking is to kill off any nasty critters or germs that might be in the the soil.  I think it can't hurt.

The magnet is remove any magnetic particles in the soil that migh be sucked up by the magnets in the motors of your locomotives and damage the gears and other parts.

Hope that helps

 

[gandydancer19]

The hobby scenery products are more consistant and you can get the same results all the time.  The only non nodel RR hobby scenery product that I use once in a while is sand.  But I also get it from a craft store so I don't have to do anything with it before I use it.

[carl425]

mlehman

The hobby products are just so much easier to use, more consistent, and no worries about stuff in them.

Agreed.  The other issue for me is that real dirt is out of scale.  A grain of real sand is about the size of an HO scale golf ball.

[cmrproducts]

I use Kids White Play Sand (I get it from the Big Box Stores) $3.00 for 50#

It is sifted and sanatized - can't get much easier than that - once one tries the backyard dirt and having to bake it and run a magnet through pounds of it!

The Big Box Store also have Morter sand - which is the same cost - but it needs to be sifted.

It has a more Brown color to it and it works great for the Western PA ground color!

Save your time and just purchase a bag and get on with your scenery work.

BOB H - Clarion, PA

[cacole]

We've used quite a bit of real dirt on our HO scale club layout, mixed with craft paint and plaster, and have had no problems with it.  Here in the dry Arizona climate I see no reason to bake it -- the sun has already taken care of that.

 

[mlehman]

joe323

The magnet is remove any magnetic particles in the soil that migh be sucked up by the magnets in the motors of your locomotives and damage the gears and other parts.

Joe,

You could try removing all those particles with a magnet, but I wouldn't trust the stuff still. Best just to use the magnet to test for the presence of ferrous metals. If the test is positive, then best to move on and try something else IMO.

[selector]

I sifted garden soil, with loam in it, for my second layout, and I thought it turned out pretty well.  I used panty-hose, and mixed the fines with some plaster of paris.  I rolled it about 1/8" thick and then wet it all with a yellow glue solution.   It hardened nicely and stayed put unless I got careless and lifted a scab of it.  A replaced scab, rewetted, was an easy fix.

 

[Marty C]

I have used both real dirt and commercial products. I have a lot of real dirt on the layout. Once sifted it appears realistic enough to my eye. I did not bake or use a magnet on it and have never had critter or ferrous metal problems but I do not use it for ballast. The detergent/white glue approach has worked well for me also. I then sprinkle commercial ground cover on the dirt if I am looking to add some color. I have also collected soil from the geographic area the railroads depicts and I think it adds a little to the authenticity and does reduce the cost when trying to cover large areas.

 

Marty C

[HaroldA]

I use real dirt in many places.  I either gather it from one specific place or I buy ripped open bags at Lowes and get a discount.  After baking to dry it out, I run it through a kitchen strainer to separate out the small sticks and other pieces of stuff which I save and use in other places.  It can be run through a fine tea strainer to get it down to dust but I don't bother.  Once it's spread around and other materials applied, I spray it with wet water and then dilute matt medium.  Works like a charm.

Nothing like the real thing.

[cowman]

I have some sand that I collected for the layout.  Sifted it through several screen sizes, then I ran a magnet over the fine dirt.  The amount of material on the magnet was amazing and very difficult to get off the magnet.  I did use the sifted sand after several magnet passes, but I kept it away from the tracks "just in case".  I sprinkled it on the wet paint and it has held just fine.

Good luck,

Richard

[crhostler61]

I use real earth quite a bit. Northern Nevada has a wide range of colors and you don't have to dig to get them. Vegetation is thin and there are in my immediate area at least 8 distinct tones that can be seen roadside. I scoop a coffee can full and take it home and sift to the grade of fine sand. I also have several cans of grave used for when the local municipalities rehab roads...this stuff translates in HO scale into boulders and rocks from about truck tire diameter and smaller.

Mark H 

[trainnut1250]

I use real dirt all the time with no problems.  No baking and no magnets. Here is a quick run down of the techniques I used with real dirt to create the look in the bottom photo.

 

I found some dirt whose color was close to the area I am modeling.  I sifted it down to fine powder.  Biggest issue here is color of the dirt after glue application.  Most dirt dries considerably darker after gluing than the dry material that you start with..  Some testing will be needed to get the color right.  Get a shade of light grey (powered pigment, or dirt) and mix with your dirt until you get the right formula.

 

I applied the dirt in layers.  For the first coat I applied the dirt to the track and tried to get it as perfect as I could.  This was sprayed with wet water and soaked with a diluted white glue solution.  last part is to spray (lightly) water over the area to wash dirt off of the sides of rails etc...After drying there will be voids, etc. 

 

The next coat is a fill coat that is applied and wetted and glued to even out the base coat.

 

After drying the area should be well covered with no holes.  The finish coat is done by sifting the dirt into glue applied to the dirt surface.  The glue must be carefully placed so that it doesn't wick up rails etc...

 

Depending on the look of the last coat when dry, I will usually sand the surface with 120 grit paper and finished with some weathering chalks to give the right dusty look.

 

 

 

 

Here is the look after the base coats but no sanding.

 

 

 

 

 

 

 

 

 

Here is the finished look after sanding but without weathering powders.

 

 

 

 

 

 

 

 

 

Here is the look with sanding and powders.

 

 

 

 

Real dirt does require some patience and experimentation, but I think the final result is worth it.

 

Guy

[wp8thsub]

wdcrvr

Some people have made a point of saying they baked the dirt in the oven first and/or ran a magnet over the dirt before using it on the layout.

What is the reason for baking the dirt and how important is it?  Same for the magnet issue?  What are the risks involved in just using the dirt without these preparations?

I use real dirt as the base ground cover literally everywhere on my layout, and also use real dirt and sand for ballast.  Maybe this makes me naughty, but I never bake it or use magnets on it.  I've been using dirt like this for about 30 years and never had the slightest problem with critters or other issues.  That isn't to say such problems can't occur, but I think there's more fear about their potential than actual bad experiences.  

I remember one modeler say he ended up with so many metallic particles in some ballast it caused him trouble shorting the track.  I don't recall what material he used or where he got it.  Such things may not be magnetic, so if in doubt try a test section of any material before committing to it as ballast.

Also, it seems that sprinkling dirt on your layout and spraying with diluted white glue would just give you muddy white glue.  Doesn't this mixture tend to flake off of the layout?

Nope.  I apply basic ground cover by brushing diluted glue onto the layout surface, then applying the dirt/sand over it.  If anything doesn't absorb glue, I'll spray with "wet water" (water with a surfactant like alcohol or detergent added) and glue again.  When using sand for ballast, I apply just like any other ballast, then spray with the wetting agent and add glue.  The latter process applies to larger talus material too.  The process doesn't create mud if done right.  It's also very solid and stays put.  It won't flake off without taking the underlying scenery plaster or foam with it.

If you are in favor of real dirt I would like to know why.

I like having a naturalistic color and texture in place.  Other commercial materials like ground foams or static grass can benefit from something under them so thin spots don't look like painted plaster or foam.  

Natural dirt/sand/rock can fill and smooth the scenery surface to a more realistic contour.  They can build up railroad embankments so they look like actual fills.  Commercial alternatives are usually much more expensive, and lack variety in color and/or texture.  With larger rocks for talus material, those sold commercially usually have the fine stuff sifted out so you can't replicate the full range of textures.

Here's a scene where I'm establishing basic ground cover and fill contours with fine sand.  The railroad fill and road are built from different colors of sand, and they naturally form realistic shapes.  Underneath all this is plaster hardshell.

This is the completed scene.  The road received dry-brushed acrylic weathering.  Once the base sand layer dried, it remained stable while additional coats of diluted glue were brushed on or applied from a bottle as I added grass, ballast and other scenery materials.

This area was finished mostly the same way.   Here I also planned to use some larger rocks to create the fill and build around the bridge abutments.  Again dirt/sand will be used under all of the ground cover.

With the dirt/sand/rock glued down the same location looked like this.  A lot of texture variation is possible.  Color can be adjusted too.  I dry-brushed the rocks with acrylic to lighten them after they were glued down.  Doing so allowed me to match the natural rocks to my painted plaster rockwork.

Natural materials create much of the texture here.  They show through and around the other ground cover, creating an effect that wouldn't be nearly as easy to achieve without them.  Colors were adjusted as needed with dry-brushing to match the plaster.

[HaroldA]

I can agree with Rob's comment - "It's also very solid and stays put.  It won't flake off without taking the underlying scenery plaster or foam with it."  I had to remove a section that was glued down and I needed to take a chisel to it.  Not only did it finally come up. I also brought some of the plywood base with it.

One more comment about my dirt, since I model a portion of the Upper Peninsula of Michigan, I usually collect my dirt from one specific two track back  in the woods up there.  I didn't get there this summer so I bought play sand from Lowes but I just won't be the same. 

[rrebell]

The only real problem with real dirt (after sifting) is that in many areas it is just too dark, some mix in plaster to lighten it and are happy. I personaly went with zip texturing which uses plaster and pigments, like that alot as I can start with a basic mix and change the color as I move toward the background creating a forced perspective.

[BATMAN]

I have used real dirt and have baked it, sifted it through some very fine strainers and used it to great success on the layout. I think it really depends on where on the planet you live as to whether you would want to use the local stuff. I had no magnetic bits come up and it sifted almost to powder form.

Since I got my airbrush I have been using tile grout and thinset left over from doing bathrooms I just put glue down with a paint brush and sprinkle it around. If the colour is not right I use the airbrush, or squirt bottle and even weathering powders to get a good shade of Prairie farmland, West Coast or Rocky Mountain terrain.

My $4.00 magnet pulls all unwanted bits off the layout, even from great heights.

 

[CTValleyRR]

I think the real reason people use dirt is because it's free for the taking.  I've never been sold on its superior realism over commercial products. It's all about how you put it down.  It can be used to build terain forms, but so can Sculptamold.  By laying a layer of earth colored foam under the green stuff, I achieve the same effect as using dirt over paint.

Where I live, I KNOW there's iron in the soil, because my well water is loaded with it (I need a special filter to get rid of it).  Likewise, the soil here is teeming with life, so I would never risk bringing something inside that wasn't sanitized.

And dirt is only a good color match if you're modeling an area near your home, otherwise you have to travel to get it.  A minor headache, at least.  For me, commercial products are easier to blend to get the look I want.  Plus, the commercial stuff comes ready to use, no nylons, cheesecloth, or tea strainers.