Foam Thickness - Does it Matter?

[howmus]

QUOTE: Originally posted by simon1966

I used plaster rock castings over a layer of plastercloth and gypsolite plaster material. I find it easier and quicker to get the more subtle contours I need than carving the foam. I just get the foam to the rough shape I need.

I agree wholeheartedly with simon. I like the texture and feel of plaster for getting the subtle shadings and fine detail I like. This was done with hydrocal castings.



I have used foam as a basic shape but I like to cover it with plaster (cloth) to get the look of terrain. Most (but not all) of the foam layouts to me look like..... Well..... Painted foam???? [;)]

[rrinker]

QUOTE: Originally posted by simon1966

QUOTE: Originally posted by rrinker

Off the main subject - but Simon, does your fascia extend below the side rails of the benchwork, or did you cut into the side rails as well to place the Digitrax UP there?

--Randy

Randy, my side rails are 2 x 4 as mentioned above. My facia is about 3 " deeper, so the UP is right up against the underside of the side rail. The top face plate screws are in the 2x4. The joint in the facia on the right is not very good and will be filled before I paint, but you can see the 2x4 thru the gap. My layout is also very low with the top of the bench work only 28" off the floor. My layout is for the kids to enjoy as much as me, so I built it with them in mind. In the future I might put in an upper deck.

OK, great. I am orderingmy UP's this weekend, and since I still have to be able to get under my layout as it exists now, I can't drop the fascia more than a couple of inches below the side rail. At least not in the middle, which, of course, would be the ideal location for the plug panel. The other option I saw was in MR about adding DCC to a layout, it was a foam top layout, and I saw in the one picture they cut out space to clear the panel connection (it was an Atlas cab panel but basically the same thing as the UP5) and put it up near the top of the fascia.

--Randy

[simon1966]

QUOTE: Originally posted by Robert Knapp

simon1966

Just a thought, is there any access from underneath behind the track for track cleaning or derailments? Couldn't tell from the pics how much access you have from each portal.
Bob K.

There is a lift out section! If you look carefully at the completed picture, you can just about make out a fault line above the lower rock castings. The picture above is of the foam with the lift out section removed.

[bogp40]

simon1966

Just a thought, is there any access from underneath behind the track for track cleaning or derailments? Couldn't tell from the pics how much access you have from each portal.
Bob K.

[simon1966]

QUOTE: Originally posted by rrinker

Off the main subject - but Simon, does your fascia extend below the side rails of the benchwork, or did you cut into the side rails as well to place the Digitrax UP there?

--Randy

Randy, my side rails are 2 x 4 as mentioned above. My facia is about 3 " deeper, so the UP is right up against the underside of the side rail. The top face plate screws are in the 2x4. The joint in the facia on the right is not very good and will be filled before I paint, but you can see the 2x4 thru the gap. My layout is also very low with the top of the bench work only 28" off the floor. My layout is for the kids to enjoy as much as me, so I built it with them in mind. In the future I might put in an upper deck.

[selector]

Pete, I had very good success with a wire brush when shaping the sides of hills of stacked foam. You know, the wooden one with the handle and looks like an oversized toothbrush? Really great when trying to get your foam grades smooth. Use long straight strokes...and a shop-vac.

[rrinker]

Off the main subject - but Simon, does your fascia extend below the side rails of the benchwork, or did you cut into the side rails as well to place the Digitrax UP there?

--Randy

[simon1966]

QUOTE: Originally posted by petejung

Simon - What did you use over the top of the foam to make the mountain?

Where I work, I can get a hold of a lot of cardboard, which I used to make the frame\cross sections of my big mountain, bsically following the woodland scenics way of making the mountain... But I like that foam idea. To me, it seems much more 3-d and therefore easier to visualize the final outcome.... Nice work!

I used plaster rock castings over a layer of plastercloth and gypsolite plaster material. I find it easier and quicker to get the more subtle contours I need than carving the foam. I just get the foam to the rough shape I need.

I happened to use 2x4 as well, because I had a lot of scrap lumber left from when our roofing contractor miss measured the roof trusses and they showed up a few " short. You should have heard the language when they were lowerd onto the house and went right between the walls. They just dumped the trusses and had them re-made. I cut the scrap ones up with my circular saw and have had a supply of lumber for projects for the last 4 years!

[orsonroy]

Pete,

You don't need to add anything over foam, besides scenic stuff. With a little practice, you can carve/sand foam into anything you need, without having to resort to a layer of plaster over it. Besides, foam will take a pretty good blow without destroying the scenery "shell" over it. Whack a plaster-based layout and you've got a white hole in your layout.

And don't foget: you don't really NEED substantial benchwork for a model railroad. Save the 2x4s for some other project. We're dealing with little toy trains here, not tapdancing elephants.

[Anonymous]

Simon - What did you use over the top of the foam to make the mountain?

Where I work, I can get a hold of a lot of cardboard, which I used to make the frame\cross sections of my big mountain, bsically following the woodland scenics way of making the mountain... But I like that foam idea. To me, it seems much more 3-d and therefore easier to visualize the final outcome.... Nice work!

[simon1966]

I used 1" because I was able to get a lot of decent size offcuts from a friends siding job.



I found I could build it up quite well. I also used some of the bead white foam from packaging to build up the sub structure of my hill. It is not too clear, but the front siding track drops down about 1" using wedges of the foam that I cut and curved to allow the drop on a curve. I like this method, as I was able to make elevation easments with it as well.

This is how it ended up.

[Anonymous]

Thanks for your input, everyone.

Seeing as I am getting free plywood and stick lumber, I think I'll be able to build the layout plenty strong to support all the weight I need, and then get away with 1" foam. I would use probably even less than 1", but I want to leave myself the option to go down a little bit if I decide to later on.

[nfmisso]

The two reason to go thicker are: 1) strength and 2) stiffness.

Both are related to the thickness cubed; thus twice as thick is eight times as strong and eight times as stiff.

[selector]

I have to agree, Pete. I started off with 1" because that is what the World's Best Hobby DVD said to use, and I knew no differently. You can use pretty much whatever you wish, provided it can support what you weight it with, and be managed well enough during track leveling and shaping, including grades.

Straight plywood will be noisy without a sub-roadbed and roadbed of 'quiet' material. I have my foam attached to 5/8" plywood, and it is probably 'normally' noisy.

If you are going to do cuts with grade or level, I would strongly recommend you buy the 1" and cut strips as you need to stack them for cuts, hillocks and mounds, etc. Gouging out 2" foam is going to set you back all that initial expense of buying the foam, and then make you cut out and scrub away in waste more than merely cutting 1" to fit. Am I making sense?

[dave9999]

The thickness really depends on how much you need to model "down". If you
are planning to raise the track on inclines, then, in reality, you dont even need
a foam base. In other words, foam is used to make terrain changes easier, but
you are doing just that by raising the track itself.

In the photo in my sig below, all of this was carved out of the foam. I could
have gotten the same effect by raising the track on risers and modeling
the scenery "up" to the track. Click the photo to get a better view.
Good luck, Dave

[Anonymous]

Is it true that the old saying "Size Doesn't Matter", or does it?

I'm starting to plan the expansion of my layout (of course, much before the current layout is "finished")... Mainly because where I work is throwing out lots of OSB, Plywood and stick lumber, which I am collecting and storing for future use...

On a trip to Home Depot yesterday for a non-related item, I noticed that not only do they sell 2" thick foam, but they go all the way down to 1/4" foam.

When I started the current phase of the layout, they didn't have anything other than 2" at this Home Depot, which was fine, b/c I needed 2" stuff anyway, as I wanted to be able to cut down into the foam for scenery purposes... But the stuff is $24 a sheet .

The new expansion is going to be considerably larger/longer, so I don't have to go down, I have enough run to go up inclines, so I don't necessarily need 2" of foam, I could use less, and get away with saving a couple of bucks... Well, I guess not really saving a couple of bucks, who ever really saves any money in this hobby....Let me rephrase - keep a couple of bucks in my pocket for a few minutes....

I am thinking maybe 1" is going to be enough thickness. I am interested in others' thoughts on this.