Foam mountains and Cast Portals

[jacon12]

Am I apt to have trouble with this portal? I do not plan on running modern, long cars or engines, the time period will be mid 50s.

Also, as you can see below, I have a 2 inch foam base and I'm currently building foam hills..

I'm wondering if I should somehow fill the vertical cracks between foam sections (after the layers are glued together) and simply paint the hills and other base or use the hydrocal soaked paper towel method and cover the foam based hills thus taking care of any cracks between sections of foam. If its to be fill the cracks what is the best filler to use?
Other than hiding any decrepancies underneath, what is the advantage of using the hydrocal method?
Thanks,
Jarrell

[grandeman]

I don't see any problems at all with the tunnel portal. I'd recommend that you cover the foam with plaster cloth (or go the cheap route and use paper towels) and scenic the hills from there.

[Medina1128]

If you're worried about the cracks (which I wouldn't) there is a foam putty that will fill them in. Once you cover them with plaster, they shouldn't show. In fact, with a little creative carving along those cracks, you can make some great erosion effects. Not to mention the inevitable cracking rocks do when the weather changes.

[simon1966]

Hi Jarrell,

If your tunnel is on a curve, take your longest locomotive and rolling stock and run them thru the tunnel as you have it set up now to verify that there is no possibility of an overhang hitting the portal. Adjust the portal from side to side to get the best clearance.

I used a thin layer of plastercloth and then a thicker coat of Gypsolite plaster and these hide any small gaps and irregularities in the foam sandwich layers.

[selector]

Use PL300 to glue the portal to a fairly flu***unnel face, Jarrell. youonly need a couple of dabs to hold it in place. Then, as the others seem to agree, use plaster cloth in thin strips, and overlay them a couple of times for added strength. Erosion could be good, or just cast some plaster rock faces, and place them around and over the portal for a dramatic blasted-out look.

Paint the portal BEFORE INSTALLATION with a somehat dilute mixture of acrylic paint. I used some yellow, some slate grey, and maybe a very little burnt umber to make it look rock-like, and then smoked up the arch and upper side walls with acrylic black in a heavy wash. Don't use straight black, as it will look odd.

[jacon12]

I appreciate the advice. I won't lose sleep over the cracks but I'll try to keep them as small as I can. I need to find another sheet of the foam and get this hill up to its final height so that I can work on the spur running from it down to the yard (about 16 feet away). After that I've really got to work on turnouts, sidings and other spur tracks.
I don't know what I'd do without ya'lls help. Well, yes I do.. I wouldn't even have attempted this.
Jarrell

[jacon12]

QUOTE: Originally posted by grande man

I don't see any problems at all with the tunnel portal. I'd recommend that you cover the foam with plaster cloth (or go the cheap route and use paper towels) and scenic the hills from there.

I kinda like the cheap route, if it works. I need to save up some money for a Shay and a mainline steam locomotive. [:D] When you say paper towels, do you mean the heavier duty kind like the solid blue or brown ones found in auto garages?
Thanks Grande man.
Jarrell

[jacon12]

QUOTE: Originally posted by simon1966

Hi Jarrell,

If your tunnel is on a curve, take your longest locomotive and rolling stock and run them thru the tunnel as you have it set up now to verify that there is no possibility of an overhang hitting the portal. Adjust the portal from side to side to get the best clearance.

I used a thin layer of plastercloth and then a thicker coat of Gypsolite plaster and these hide any small gaps and irregularities in the foam sandwich layers.

Simon, thats one of my problems right now... I only have two diesels and I want to get a steam locomotive, something like would have been used in the foothills of the North Carolina/Tennessee area around 1940. So I don't know how much overhang I'm going to be faced with. I do know those were not huge engines so hopefully I won't have a problem. I do know that a steam engine that is being used today in the area for the tourist business is a 2-8-0 Baldwin built in 1942 but I need to check todays models and see how much overhang they have.
I appreciate your help!
Jarrell

[grandeman]

QUOTE: Originally posted by jacon12


I kinda like the cheap route, if it works. I need to save up some money for a Shay and a mainline steam locomotive. [:D] When you say paper towels, do you mean the heavier duty kind like the solid blue or brown ones found in auto garages?
Thanks Grande man.
Jarrell

I used the better quality kitchen towels but the heavy duty brown type would work better and hide dings somewhat later on. Mix standard plaster to a very thin consistency (soupy) double the towels, dip them and apply. When dry, go back with a thicker coat of plaster.

*Tip-- An old toohbrush does a great job of sculpting what looks like blasted rock into plaster.

[simon1966]

I was going to suggest you look at my picture trail site as the right end of my hill has a portal at the end of a curve, but I just looked at the image and see that there is a tree obscuring the view in the photo on the site. Looking at your portal, it seems to be a fairly standard one and I suspect it will be fine. Just don't glue it in place until you have had a chance to test it with the future loco. Another idea would be to take a flat car or gondola and put a cardboard cutout on top with the dimensions (length and width) of the future loco without tender. This would be a far worse overhang than the loco as the wheel sets will not be as far apart. If this goes thru, you will be fine for sure.

[oleirish]

QUOTE: Originally posted by jacon12

Am I apt to have trouble with this portal? I do not plan on running modern, long cars or engines, the time period will be mid 50s.

Also, as you can see below, I have a 2 inch foam base and I'm currently building foam hills..

I'm wondering if I should somehow fill the vertical cracks between foam sections (after the layers are glued together) and simply paint the hills and other base or use the hydrocal soaked paper towel method and cover the foam based hills thus taking care of any cracks between sections of foam. If its to be fill the cracks what is the best filler to use?
Other than hiding any decrepancies underneath, what is the advantage of using the hydrocal method?
Thanks,
Jarrell

Looks good Jarrell,I use a stuff I get at the hardware store It is a lite filler for walls and seams,the way to tell you are getting the right thing is pick up the container if it fells real lite thats what you want.After I stack my foam and shape it then glue it togethor(use tooth picks) I fill the seams with this stuff.OH! buy the way it is good for filling holes in the wall also[:D]I think that is what it was for in the first place[8D]

Jim

[Medina1128]

I read in Model Railroader that the blue auto shop towels work best. They're tougher and not as apt to fall apart. I've used them and found that the mixture needs to be more like thick gravy ( a little thicker) than normal. Judging from the picture of your diesel locomotive, I don't think you'd have any trouble with clearance with a steam locomotive, even a Challenger or Big Bigboy. The curves look like you'd have some overhang with a long one. But an Alleghany type loco should fit just fine.

[selector]

Jarrell, if you have anything as small as a Shay or Connie, it will not be a problem. As Marlon says, it is the long pax cars and long locos, like FEF, articulated, and so on that may come to grief in your portal. Just lay the portal temporarily, and run something long (about 12") through it on that curve. If you have even 1/4" clearance on the inside edge, you can safely leave the portal where you have it.





As you can see, it can be done. Note the smoked-up portal.

[orsonroy]

OK, my take on all of this:

QUOTE:
Am I apt to have trouble with this portal? I do not plan on running modern, long cars or engines, the time period will be mid 50s.

Wow; that's a TALL tunnel portal! Definitely paint it beforehand (water-based paints; use the cheap stuff, since the plaster will soak up the paint). And I'd personally cut at least 1/2" to 1" off the bottom of the portal, to bring it to a more realistic height. Notice how little clearance there is with these two tunnel portals, as compared to your model:
http://photoswest.org/cgi-bin/imager?11005669+Z-5669
http://photoswest.org/cgi-bin/imager?11005949+Z-5949
Yes, you'll have to have SOME extra clearances for your model curves and car overhang, but try not to make it as cartoonlike as the stock portal.

Don't forget to add some scenery to the insides of the tunnel, at least for the first foot or so. Notice how tunnels through solid rock look in real life:
http://photoswest.org/cgi-bin/imager?11005677+Z-5677
And notice how tight the clearances are! I'd model this by "chunking" the surface of the foam by using a flat screwdriver to pry off small chunks of foam. Paint the inside with cheap latex paint, and weather heavily with black washes.

QUOTE:
Also, as you can see below, I have a 2 inch foam base and I'm currently building foam hills..

I'm wondering if I should somehow fill the vertical cracks between foam sections (after the layers are glued together) and simply paint the hills and other base or use the hydrocal soaked paper towel method and cover the foam based hills thus taking care of any cracks between sections of foam. If its to be fill the cracks what is the best filler to use?
Other than hiding any decrepancies underneath, what is the advantage of using the hydrocal method?
Thanks,
Jarrell

You can fill small cracks with latex caulk (or hde them with bushes & trees), and larger cracks with Great Stuff "foam in a can". Other than that, there's really no need at all to cover up a perfectly good foam surface with plaster. Here's why:

1) foam carves and scapes easily. With a bit of practice and trial & error, you can create as good of rock surfaces with only foam as you could with plaster. Hollywood now almost exclusively creates "rocks" out of foam.
2) The base of your rock surface is already there, and already paid for. Why add to the expense of the layout by adding paper and plaster?
3) Plaster is messier to work with, by being a "wet" mess. Foam is a "dry" mess, and cleanup is faster. In addition, the wastage of plaster is enormous, and prep/cleanup time is at least three times as long as with foam.
4) plaster breaks easily, relative to foam. Add a layer of plaster to a foam (or no foam) layout, and if somebody whacks the plaster, you end up with a nice, white, crumbly hole in your scenery which will require a long time to fix. Foam won't break under normal wear & tear, and if somebody whacks the foam-only scenicked surface, TWICE as hard as the force that broke the plaster, you'll just have a bit of randomness to your scenery.

Advantages of Hydrocal? Keeping the Hydrocal merchants happy.

Of course, these are just my opinions...

[jacon12]

I appreciate all the information! Ray, I wonder why Woodland Scenics makes this portal so tall? Maybe a lot of modern day stuff going thru it? Anyway, I've decided that I'm going to take two or three scrap pieces of foam and experiment building a mini mountain, glue the layers together, try my hand at carving (that oughta be good for a chuckle or two), paint it and try some vegetation on it, just to see how it will look. I'll fill the cracks with latex caulk right before the painting step.
I think someone told me they liked the plaster soaked hydrocal (or plaster) method because it allowed using diluted washes for ground color and it looked more realistic than a coat of paint. I dunno.. having never done either one.
Jarrell

[orsonroy]

I don't buy the "washes are best with plaster" arguement. With a dead flat and slightly gritty latex paint added as a basecoat to the foam, you can add washes all day long. And don't the plaster advocates have to start the plaster off with a basecoat of something too?

Practicing on scrap is always the best method for anything. That's how I started scratchbuilding. For foam, I just dove right in (and you could tell!)

[jacon12]

QUOTE: Originally posted by orsonroy

I don't buy the "washes are best with plaster" arguement. With a dead flat and slightly gritty latex paint added as a basecoat to the foam, you can add washes all day long. And don't the plaster advocates have to start the plaster off with a basecoat of something too?

Practicing on scrap is always the best method for anything. That's how I started scratchbuilding. For foam, I just dove right in (and you could tell!)

[(-D] Thats always been my problem, I just dive right in. Don't read no stinkin instructions! Well, not thorougly anyway. Thats how I get buildings with parts left over and such.
But, I am going to try it. I've got a few smaller pieces of foam so I'll glue two together and carve away!
Jarrell

[bogp40]

Jarrell,
I agree that sealing/ base coating the plaster is the way to go. Stains and washes work well, however leaving the plaster unsealed can lead to unwanted stains and discoloration during the rest of scenery construction.
Bob K.

[Medina1128]

Jacon, you can take all those leftover pieces and create a nice landfill, or junkyard. Although I think now they call them "recycling centers". We got tossed out of an automotive junkyard for refusing to call it an "auto recycling center"... sheesh, how touchy can you be!?!