Foam sculpting help needed

[Blind Bruce]

OK, I have the cork roadbed on two inch foam. I next want to sculpt a ditch on either side. A straight knife doesn't seem to be the tool of choice, but I do not have a hot wire setup. Is there a better way ti carve out the ditches?
Many thanks,
BB

[randyaj]

I use a very rough half-moon file, (there is a name for this but last time I tried to post it the post was automatically edited) it will quickly erode your ditch.
Randy Johnson

[orsonroy]

Use a long blade utility knife, and make a V groove cut into the foam. Foam's got some self-healing properties (at least, the knifecuts won't really show), so as long as you've got a nice sharp blade, everything will come out fine.

At least, this is how I've cut over 300 feet worth of ditches on my layout...

[loathar]

Those illigitimet child files work well. See-if you say it right it doesn't get edited.

[selector]

I would use a blade to notch the ditch, and then a small wire bru***o round out the surfaces and edges to a natural look.

The blade will clear out the intial ditch very quickly, and the wire brush, if messy, will do a god job at the rest. If you want a more polished, or smoother look, finish it with a file that, uh... knows not its father. [:D]

[randyaj]

thanks for the alternate names for that -well ugh- you know- fatherless file:)
Randy Johnson

[orsonroy]

Use the term rat tail files instead of bastid files...

[Anonymous]

You might want to try brushing the foam with lacquer thinner. You can vary the depth of your trackside ditches by applying a number of coats of lacquer thinnner. You can caused track ditches to look a little uneven if you want.

Alternatively, you can purchase a length of Woodland Scenics ni-chrome wire from your local LHS for $1.98 and make a simple double-V hotwire with an old power pack and popsicle sticks. Cut a pair of guide notches in the sticks so that they can be pulled along the track. This method make smooth, uniform, ditches that follow the track exactly.

My local hobby shop guy taught me these tricks. I'm sure gonna miss his advice when all of the LHS's go close their doors.

[Anonymous]

Try the dollar stores near you for razor blades and files. I found wood ones to use tonite and some painter brushes also, 4 for a dollar, that I can use to paint the foam mountains.

[loathar]

Capn- Thats a neat trick. I new my old tyco paks would come in handy one day. Do you use the track or the acc. terminals?

[Blind Bruce]

Loathar, you would use the DC output as it is variable. The ACC is a constant voltage and would be hard to work with.
I want to know more about those popsicle sticks though. How does that work?
BB

[Anonymous]

I wi***here was a nice clean answer to that question. The truth is that the solid foam, while having some very nice qualities, does not cut, form, sand, smooth, or dig very well. It's primary advantage is weight, or lack of it. I have been in this layout building task for about 40 years, some of the new products are very good at doing somethings, but not so good at others. It does make a good material to use under the track. It is light and easy to cut for that purpose. However, if you need ditches or other inground characteristics, the foam will have some not so desirable charcteristics. Such that, it does not like being dug out, as you must do to accomplish some of the desireable features we want on the layout. My only suggestion is try to foresee what needs to be done at the next step. As, in this case, cut the foam a bit narrower and put the ditches in the hardshell ground cover that needs to be done after the trackwork is mostly finished. It is possible to round the corner of the foam then use the ground cover to form the ditch. This will produce a better transition from the stone roadbed to the mostly dirt ditch. It will also be much cleaner and faster. I have never used much foam on the layouts I have built in the past. I can see a wider use for it on my next layout.
My advice is not to use the same material for so many different uses. By using different materials for various features we can better represent the many types of materials found in nature. I wi***his were a video presentation as it would be much easier to show with pictures what I tried to describe with words.
Any questions just let me know. I will do my best to answer.

[Anonymous]

I use a variation on CapnAmerica's method. I cut with a straight knife and spray with a solvent based spray paint of the color I want for my base coat. Too much spray can ruin the work. This also works for producing weathered rocks with faulting.

[daschilling]

For some foam cuts, I use an electric carving knife. (For peace in the family, buy another one, and leave the one already in the kitchen for the Thanksgiving turkey.) It works fair one deep gouges and very well for surface texturing. It's not quite as messy as the wire brush, and does have its limitations.

[johnd]

I would look at trying a melon baller (kitchen tool) and scoop out the foam to form a rounded bottom
of your ditch. It might be too dull at first, but i'm sure an edge can be put on it.

[Medina1128]

I found a small wire brush (about the size of a toothbrush). A couple of passes down the side of the track and you have some nice drainage ditches. You do have a shop vac, don't you?

[nickl02]

Avoid using a file. This creates a large mess. I learned the hard way.

[orsonroy]

A rebuttal offered by your friendly local foam advocate:

QUOTE: Originally posted by tfox60
The truth is that the solid foam, while having some very nice qualities, does not cut, form, sand, smooth, or dig very well.

I find that foam cuts, carves and sands extremely well, and has several of the same working properties as a soft wood. True, it may take a certain different set of skills to work PROPERLY, but you can achieve exactly the same results with foam as with plaster (for most applications; some rock formations ARE easier to create with plaster). And let's face it; foam cuts, forms, sands, smooths, and digs a LOT more easily than either plywood or plaster!

QUOTE:
It's primary advantage is weight, or lack of it.

I find that it's primary advantage is ease of construction, and it's relative inexpensiveness, compared to everything you'd need to build a traditional layout to the benchwork/subroadbed/roadbed/basic scenery contour level. I prefer building linear walkaround layouts. Using time saving (and actually cheaper than dimensional lumber) materials such as 2:" foam and metal shelf brackets, I had a 12x25 three level layout built to the "let's lay track!" level in about three weekends. If I had built the layout with 1x4 L girders and hardshell, I'd still be working on the thing!

QUOTE:
However, if you need ditches or other inground characteristics, the foam will have some not so desirable charcteristics. Such that, it does not like being dug out, as you must do to accomplish some of the desireable features we want on the layout.

That's why you don't "dig" out foam, you cut it. Slicing cleanly through foam with a SHARP utility knife will yield extremely precise and even scenic contours, which are more easily controlled and faster to create than hardshell. And rounding edges and ditch bottoms is easily achieved with a wire brush, sanding block, or hand rasp. Using a wire wheel chucked into a power drill works even faster, but I only recommend that for outdoor use!

QUOTE:
cut the foam a bit narrower and put the ditches in the hardshell ground cover that needs to be done after the trackwork is mostly finished.

Huh? I strongly advocate NEVER having to add a hardshell base to the top of foam; there's no point. Your scenery layer IS the foam, so you don't have to go through the extra time, expense and mess of slapping plaster around. And foam is a MUCH stronger material than a hard plaster shell. Whack sceniced foam with a elbow or hammer, and you've got more interesting microterrain. Whack hardshell, and you've got a nice white hole that you need to spend hours fixing.

QUOTE:
It is possible to round the corner of the foam then use the ground cover to form the ditch. This will produce a better transition from the stone roadbed to the mostly dirt ditch. It will also be much cleaner and faster.

I fully agree with this, for no matter which sub base technique anyone uses. The foam or hardshell base layer is only the basic structure of the scenery layer; you want to fini***he effect using various ground foams and model plant matter. One of the biggest issues I run across with adding scenery to foam is when modelers run across an undesirable seam, joint or crack. My usual answer: add a bunch of bushes there, and no one will ever see it!

QUOTE:
I have never used much foam on the layouts I have built in the past. I can see a wider use for it on my next layout.

If you haven't given foam a REAL chance on a layout, build yourself a 4 to 8 foot long practice module, using ONLY foam as a base. Try your hand at creating different scenic elements, including ditches, waterways, hills, depressions, cliffs, roads, grades, and structures. One thing to keep in mind about modelling with foam is that it takes a different skills set than working with "traditional" techniques. Keep an open mind, try not to think about how you would do something"if I had plaster", and read up on how others work foam. I think you'll find that for most of what's done in this hobby, foam is a superior, cheaper, and faster alternative to working with lots of lumber and wet plaster.

[randyaj]

Hey Ray I was just in Peoria this week, sorry I didn't know I would have loved to drop by and saw your layout! I too love foam and its versitility. Scenery goes so much more quickly than the old cardboard and brown paper sack method that I used on my last big layout. I do one thing differently though. After I have placed and carved the foam (I use a hacksaw blade a sureform and a rough halfmoon/flat file to shape it). I cover it with plaster cloth (Woodland Scenics makes it but I found another "off brand" that is the same thing for a 1.50 less at my LHS. If anyone is interested let me know and I will look up the brand name) With the foam backing I don't need to double lap the cloth as the instructions ask making the cloth go a lot farther. I then "paint on a coat of thinned sheetrock mud. If I am in a cut area, when the mud is hardening I can take a stiff bristle bru***o simulate striations in the rock. Then paint with the base color and scenic to your hearts desire. I would estimate that the method I described takes 1/3 to 1/2 the time of the cardboard/paper method. I am sold!
Randy Johnson

[Anonymous]

Blind Bruce,

The popsicle sticks are glued together with the ni-chrome wire sandwiched in between them. You might want to start by tacking the wire along the center for about an inch and a half, then bend a pointy wedge on both sides, then tack the outside wire strips to the sticks. The surplus wire should stick straight out of the popsicle stick sandwich. The wires form the power leads to your ditch hotwire. We are essentially replacing a hotwire bow with a ridgid wooden bow.

Don't forget to add a simple momentary contact switch to the circuit. This will allow you to start and stop cutting exactly where you want without tinkering with your voltage setting.

[selector]

Ray, good response above. My experience mirrors yours pretty much exactly, and I would use no other medium to form topography.

[Bikerdad]

Any form of solvent sculpting should only be performed with extreme ventilation or while wearing the appropriate air filters. This is especially true of using lacquer thinner.

I wouldn't recommend using files except for the final touchups. A better tool will be a wood rasp, much more aggressive. Probably the most useful one for our purposes would be a 4in1 tool, which IIRC combines 2 rasps and 2 files.

Surform rasps and Microplanes are both excellent tools for this purpose.

edit: Re-read the original question, we're dealing with fairly small dimensions here. Your best tools to use can be found in the woodcarving section of your local woodworker's supply shop. A micro-scorp or rifflers (curved, small rasps and files) would be perfect. I believe Micro-Mark does carry some rifflers. You may also find them at *** Blick Art Supply, or a similar retailer that services the serious art communities.

[Anonymous]

What is the conversation about popsicle sticks.? I just got in on the end of it.

[Anonymous]

The term used for files, male dogs, and children of an unknown father, refers to the type of cut on the file. This particular cut is a rather course cut and could be refered to as such. The shape of the file most often refered to here as a half-moon is more correctly refered to as half-round. I do agree with those who support the use of Sureform tools. In the bodyshop trade they are sometimes refered to as "cheese grators". Though I would recommend having a "Shopvac" type of vacuum handy when using these tools, they do work effectively. They are available as a flat, half-round, and "rat-tail" style tool.

I do like the "poorman's" hot wire tool as I fit well into that catagory myself. Be carefull about where you run the hot wire in relation to the popsicle sticks. This is not supposed to be a wood burning project. Make sure the connections between the hot wire and the supply wires from the powerpack are tight and secure or more heat will be developed there than in the wire. I know this increases to price of the handset, but perhaps a couple of small terminal blocks on the end of the sticks would make for a good connection and replacability. I just might try this myself as I am statrting a foam based layout and was looking for an inexpensive way to accompli***his task.