Ok.  I'm not just slapping things together.  There really is more structure to my methods.  Here's the list of materials that you'll need:

• Durhams Water Putty
• An X-Acto knife
• A piece of 1/16 inch thick basswood
• Elmer's Glue
• Black Acrylic Paint
• A Putty knife
• A hammer and some short brads 
• Some kind of straight edge

So what are the advantages of using water putty over plaster?  Plaster is soft, brittle and tends to shrink while drying.  Water putty dries rock hard, does not shrink and is more stable.  It will crack a bit over time with the natural expansion of your layout (which real roads do anyway).

First you'll need to cut your strips for your forms.  You can buy basswood that's "pre-cut" into 1/16 inch strips but that can get pretty pricey.   It's a lot cheaper to buy a basswood sheet and cut your own. The strips you cut don't have to be consistent in width.  They just need to be thin enough to bend for curves in your road.

Once you have your strips cut, you need to decide how wide you want your road and where you want to locate it.  The standards on road widths can vary from state to state but in general a two lane road can be 18 to 22 feet wide.  That translates to about 1.35 - 1.65 inches in N Scale.  Take a pencil and roughly sketch your road on your layout.  Once your satisifed with the location you can start putting the forms in place.  

Start at one end of the piece of basswood by wedging it between two brads that you've (lightly)nailed into your sub road bed.    

   

Continue to put in brads every two or three inches following the curvature of the road you've drawn on your layout.  As you do this gently bend the basswood so it rests against the brads you've just put in.  Put brads in on both sides of the strip(as needed) to hold it in place.

When you have one side in place you can now start positioning the other side of the form.  I used a small piece of basswood cut to the the width of the road as a spacer for maintaining consistent width between the two forms.  If you need to bend the basswood into a sharp curve, take the piece and soak the part you need to bend in hot water for about ten minutes or so.  That will keep it from breaking when you bend it.

Once you have your forms positioned you'll need to lift them up to lay a thin layer of glue underneath.  Don't overdo it on the glue.  You'll be removing the forms once the water putty dries.  Now set the strips back down in the glue and use what ever you have on hand to weigh them down (I sure did).

If you're doing a grade crossing you'll need to tape off the space between the rails to keep water putty from getting in.  I'd recommend using plaster of Paris for filling in that area (depending on the style of crossing).  Water putty dries rock hard and it will be really hard to carve out the notches for your wheel flanges and you could risk damaging your track. 

You can now start mixing your water putty.  The standard recipe is 1 part water to 3 parts putty.  Well I don't really follow it. 

I just keep adding putty and paint to the water until it gets to be almost as thick as toothpaste. 

As you add the putty to the water you'll need to keep adding paint since the putty tends to lighten the mix up.   You can use either Black Acrylic or Latex paint.  In addition the added paint slows down the curing time which works in your favor.

Now you can start filling the form in with your putty.

You can use your putty knife to scrape away any putty that falls outside the form.   Let the putty dry for a day (24 hours) before removing the forms.  You can remove the forms with your X-Acto knife by cutting where the wood and the putty join.  Don't sweat it if you accidentaly take a chip out of the road.  You can always mix a smaller batch of water putty and patch it just like the real roads.

24 hours later...Here's a shot of the road with the forms...

...and one with the forms removed.

So there you have it.  Put on your hard hat, roll back you sleeves, and get paving! You'll have a blast!

PS.  I opted not to use Plaster of Paris to fill the centers of the crossing. Insted I used re-cycled ties from dead pieces of track....Hmmm...I sense another article coming on.

Cheers!

E