M> I've never used Hydrocal. If I decided to go this route, and if I
M> added pigment, sand, dirt, etc. to the Hydrocal, does it still need to
M> be painted? And shoud the layer of Hydrocal be very, very thin? 1/8
Depends. Since the pigment, sand, dirt, etc. would be 'universal' in a
given batch and if you needed some small area to have a different base
color, it might make sense to use the 'majority' color for the Hydrocal
mix and then paint the 'minority' areas the minority color. It also
depends on how 'uniform' you want your base color. You can apply paint
(or a wash) heavily or lightly in a locally specific way. Pigmented
Hydrocal would be more universal / uniform (which is unnatural).
It is generally cheaper to not put the pigment in the Hydrocal -- it
takes a lot to get a heavy color and you can get the same effect with a
thin layer of paint on the white Hydrocal. Of course the dirt and sand
will 'color' the Hydrocal as well, again it depends on the amount. You
also want to avoid putting too much stuff in the Hydrocal -- this will
M> inch? 1/16 inch? thinner?
I've not actually measured an exact thickness. I just sort of smeared
it on -- the thickness varied, probably from 1/8" to 3/16", but could
be thinner or thicker at places, generally at places where there were
problems with the foam shaping process (nicks, chip outs, etc.). This
is not an exact science.
Suggestion: use some *scrap*
pieces of foam and build some 'throwaway'
hills / mountains. Mix up a small batch of your Hydrocal mix and smear
it on and 'experiment' until you have what you are looking for. You'll
probably also discover the mix and technique for other places in your
layout. Note: the Hydrocal sets up fairly quickly, so you'll need to do
this in small batches anyway. You'll want to prowl the local Dollar
store and get a supply of cheap plastic mixing bowls.
M> > There are several schools of thought. *I*
would cover it with a *thin*
M> > layer of textured Hydrocal. Mix the Hydrocal so it is thick (not
M> > runny) and include something to add texture, like fine sand or
M> > something. Smear it over 'wetted' foam (spray the foam with wet water
M> > (water + drop of liquid dish soap). Once the Hydrocal has cured, it
M> > can be painted with a thinned wash of Woodland Scenics Earth Color.
M> > While the coat of color is still wet, dust it with ground foam and/or
M> > talus -- the grade and color of the ground foam and talus depends on
M> > the specific scenery for the locale in question -- eg fine bright
M> > (grass) green foam, no talus for a hilly golf course, a rougher darker
M> > stoner mix for under a forest (say in New England). You'll want to make
M> > several passes (dribble on wetted 50/50 diluted white glue between
M> > passes).
M> > I've found that it is hard to get either a really smooth surface (which
M> > you really don't want) or a finely textured one directly in the foam --
M> > the foam tends to 'chip', particularly at the layer joints with shallow
M> > slopes. The Hydrocal fills in minor gaps (particularly at layer joints)
M> > and can be smoothed on to get just the contour detail you want (an old
M> > saw blade or fork or other random 'implements' can impart various fine
M> > surface details) and can have a realistic texture (with the right
M> > texturing additives). It also takes paint better, since it has a
M> > smoother surface. Also it is easier to apply a thin wash of dirt brown
M> > to the white Hydrocal than to the *pink*
foam -- you don't
M> > need such a heavy coverage to hide the *unnatural*
color of the foam.
M> > You can also dump pigment in the Hydrocal, although you would much more
M> > pigment to get things right. Of course mixing finely ground *real*
M> > into the Hydrocal might be a cheaper option (I've not tried this
M> > myself) -- cheap texture and the right color too.
M> > M>
M> > \/
M> > Robert Heller ||InterNet: email@example.com
Robert Heller ||InterNet: firstname.lastname@example.org