Skip to main content

Replies sorted oldest to newest

For a straight line, I generally use a table saw with an old blade.  You have to maintain a firm stead grip yet be ready to run away if the saw grabs the foam, melts a bit of it to the blade and sends it flying.

For terrain, I generally use a keyhole saw and or pen knife.  A steak knife can also be used.  Shaping can be done with a wood rasp and or coarse sandpaper.  The wood rasp can also be used to smack against the foam to make “tool marks” in masonry.  A triangular file can be used to make mortar/joint lines in masonry.

And RSJB18 mentioned the most important tool: a shop vac.

IMG_3487IMG_3609

Attachments

Images (2)
  • IMG_3487
  • IMG_3609

I use the tools made by Hot Wire Foam Factory. https://hotwirefoamfactory.com/

The hot wire melts its way through the foam and leaves no particles to clean up afterwards. Below are photos of a tunnel that I constructed for a client in California several years ago while I was still in the model railroad scenery business. The substructure of the tunnel is made totally from pink insulation foam of various thicknesses. All of the foam was cut with the Hot Wire knife tool. The slabs of foam board are held together with a specialized glue call "Foam Fusion" sold by Hot Wire Foam Factory.

gp_mountain_1

I engraved the stones in the tunnel portals using the scribing tool.

gp_mountain_2

Below is a photo from one of our York show booths showing a partially finished tunnel with exposed foam.

York 2014 Fall 1

Below, are two photos on the bench in our shop of a north woods diorama, that I made for a client. All of the terrain is carved from pink insulation foam.

Matt Hackenburg Diorama 001Matt Hackenburg Diorama 004

This a great way to cut foam with no residual mess. However, ALWAYS cut in a well ventilated area or outside on a sunny day. The vapors from the melting foam are highly toxic.

Attachments

Images (3)
  • Matt Hackenburg Diorama 001
  • Matt Hackenburg Diorama 004
  • York 2014 Fall 1
Last edited by Randy Harrison

I shape pink foam 3 ways:

1) If I need a clean cut, I slit it with a razor blade or utility knife, going as deeply as possible, and then snap it apart. You can then sand the remaining rough edge to make it perfectly smooth.

2) If I need a rough texture,  I carve it with a Dremel tool, using various bits for different effects.

3) If I need detailed textures, such as cut stone or concrete expansion joints, I simply emboss it, using an old set of manicure tools.

walls 9walls 8walls 6walls 5walls 4walls 3walls 2walls 10walls 11

Attachments

Images (9)
  • walls 9
  • walls 8
  • walls 6
  • walls 5
  • walls 4
  • walls 3
  • walls 2
  • walls 11
  • walls 10
Last edited by Avanti

For cutting 2" thick foam board; I use a Olfa knife with break away blade points. I bought mine in Home Depot, you can find them with the wallpapering tools. They sell the replacement blade packs with standard, and a thicker heavy duty blade, get a pack of the sturdier heavy duty blades. You can extend the blade out about 3 inches or so, with a fresh blade, and make a clean cut in foam board. Mine is the nicer knife with the black and yellow handle, and the blunt blade on opposite end for prying open can lids. I carry mine with me all the time. They are inexpensive.

Avanti posted:

I shape pink foam 3 ways:

1) If I need a clean cut, I slit it with a razor blade or utility knife, going as deeply as possible. You can then sand the remaining rough edge to make it perfectly smooth.

2) If I need a rough texture,  I carve it with a Dremel tool, using various bits for different effects.

3) If I need detailed textures, such as cut stone or concrete expansion joints, I simply emboss it, using an old set of manicure tools.

walls 9walls 5

Pete:

That is very nice work.

I use the hot wire tools, I don't like paint,plaster, glue, or any other liquid mess. And I don't like taking all day to do something.   This scene what you see is about 1/2 of it,  took 30 days from tear out, to finish. Carved and painted in the garage then moved to location in three large sections. the whole thing is about 6 x 12 feet. that curve is 120" Dia. And a 2% grade. 

IMG_6112IMG_6015

 

Attachments

Images (2)
  • IMG_6112
  • IMG_6015

I use a slightly different method.  I first slice on my table saw, 1" thick sheets of blue or pink foam into 2 1/2" wide boards.  I then hot glue them into the basic form of the scenery area I am building.  I then take a serrated knife, one of three sizes - small, medium and large - and start carving, and carving and  carving until I have the basic shape I am looking for.  Cracks and joints are then  filled with Sculptamold and left to dry.  Then the entire area is coated with a thick ceiling paint.  It is now ready for a basic color, installation of rock molds and scenery.

IMG_7053IMG_7055IMG_7064IMG_7059

Attachments

Images (4)
  • IMG_7053
  • IMG_7055
  • IMG_7064
  • IMG_7059
Randy Harrison posted:

The vapors from the melting foam are highly toxic.

I am all for good ventilation, and the fumes are irritating.  But it isn't really true that they are highly toxic. Pink foam is Extruded Polystyrene. Polystyrene is a food-safe substance.  When it is heated or burned at non-extreme temperatures, the resulting vapor is mostly CO2 and water vapor. It is actually pretty benign:

https://www.rcgroups.com/forum...-Foam-Fumes-(Toxic-)

https://en.wikipedia.org/wiki/Polystyrene

Fork, butter knife, steak knives, hack saw blade, exacto, exacto saw, flame from lighters, micro torch for shaping.

Large cuts I usually use the hacksaw or score with a box knife and snap it.

Sanding ; 220 ish 

I've used the locktite foam glue; pricy.

For less permanent stuff, I just used white glue. But nothing has fallen apart in 7-8 years.

If you chase the mess too much you'll just clean all day ;(

Vacuum and kill the lights

 

Add Reply

Post

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
Link copied to your clipboard.
×
×