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Cutting pink foam.

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Cutting pink foam.
Posted by CGW121 on Friday, September 25, 2015 4:33 PM

What tool(s) work best to cut pink foam? Drywall saw didn't work very well neither did a knife, I do not have a band saw, so what else should I try? Its the back side of a ridge that is a bear to get at, otherwise I would do plaster.

 

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Posted by BroadwayLion on Friday, September 25, 2015 4:37 PM

LION mostly uses a circular (table) saw.

But you can also cut it very nicely with a knife. You DO NOT cut through with the knife, you score it and then break it like cutting a window or a sheet of plastic.

Some time I just break it over my knee.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by RideOnRoad on Friday, September 25, 2015 5:10 PM

Another vote for scoring and snapping. I use a snap blade for scoring and for shaping foam.

Richard

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Posted by CGW121 on Friday, September 25, 2015 5:15 PM

I need to carve more than cut. I would like to build it on the bench and place it on the layout. 

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Posted by skagitrailbird on Friday, September 25, 2015 5:16 PM

If you are just trying to make smaller pieces of the foam the Lion is right. Score it with a utility knife and snap it. If, however you are trying to shape it (i.e. pieces are stacked in layers but you want to smooth off the "stair steps") a hot wire foam cutter is the answer. there is a YouTube video about making your own which I did. But you can buy a ready made one from Woodland Scenicsor Scenics Express.

Roger Johnson
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Posted by RideOnRoad on Friday, September 25, 2015 6:08 PM

I built a couple of foam mountains using a snap blade and would not use anything else (and I do have a hot-wire foam cutter). The great thing about the snap blade is that it is flexible, making it fairly easy to shape the foam. Two comments. One, snap blades are very sharp, speaking from sad experience. Two, I found a trick in cleaning up all of the static-infused foam shaving laying around--mist the shavings with a light spray of water. When they are damp, they sweep right up.

Richard

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Posted by BATMAN on Friday, September 25, 2015 6:33 PM

I use any and all implements on foam. For cutting a shaped piece, I have a pistol grip hack saw that works really well.

For cleaning up the bits, I put a garbage bag in the shop vac. I then dump the bag into a large tupper ware bin under the layout. All these bits make good morraine at the bottom of my cliffs.

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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Posted by CGW121 on Friday, September 25, 2015 6:53 PM

The bluffs along the Mississippi River is the look I am after. Plaster and wire is easy but I have to contort myself in painfull ways at do it in position.

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Posted by BATMAN on Friday, September 25, 2015 7:03 PM

I just went to Google images to look at the Mississippi Bluffs. I think if you use a fine tooth hack saw blade, you will get the look you want. That layering should be easily obtainable by dragging the blade across horizontally after you cut it.

My foam Rocky Mountains.

 

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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Posted by ARTHILL on Friday, September 25, 2015 7:39 PM

My main tool is a serrated steak knife. I use the point for gouging a lot. I sharpened it to cut better striations. For sedamentary rock like the Mississippi bluffs, I use a wire brush to finish. My best advice is to be rough and brave. If it doesn't look quite right, dig a lot deeper and rougher. Be sure and get the vertical cuts in deep enough.

If you think you have it right, your standards are too low. my photos http://s12.photobucket.com/albums/a235/ARTHILL/ Art
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Posted by PennCentral99 on Friday, September 25, 2015 8:15 PM

I must be the odd man out.....I use a double sided drywall saw and it works fine for me. Maybe it's because I use 2" foam and the long serated blade cuts right through

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Posted by davidmurray on Friday, September 25, 2015 9:47 PM

I think this is another case of "whatever works well for you"

I have used 26" handsaw, utility knife scoreand snap, steak knife,etc.

For shaping:  steak knife, surform rasp, coarse sandpaper.

Any other tool mentioned or thought of would work.

For bonding layer together: yellow glue, white glue, construction adhesive, latex caulking.  Again your choice.

Dave

 

David Murray from Oshawa, Ontario Canada
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Posted by mlehman on Saturday, September 26, 2015 1:50 AM

For cutting and carving, I usually use this:

But be careful, or you might end up like this (my worst injury in 5 decades of model RRing):

 

 

Mike Lehman

Urbana, IL

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Posted by BroadwayLion on Saturday, September 26, 2015 6:54 AM

A Coping saw ought to work for shaping, that is if you do not need to spend the money for a hot wire. Still, breaking it over your knee will give you intersting shapes that you can use for your cliff side.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by BroadwayLion on Saturday, September 26, 2015 6:56 AM

Oh. Thats your thumb! I thought I was looking at a stuffed animal. I did not see the knife unitl I replied. I hought you were cutting the foam with the aeroplane.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by lotrain on Saturday, September 26, 2015 7:56 AM

I use a hacksaw blade with 32 teeth per inch. I wrap tape around one end for about 4 inches to protect my hand. This will leave a very fine dust when sawing. It is fast cutting and easy to do. These blades are at any hardware store. They are sold in 10 and 12 inch lengths. I prefer the 12 inch.

                    trainnut

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Posted by mlehman on Saturday, September 26, 2015 9:09 AM

BroadwayLion
Oh. Thats your thumb! I thought I was looking at a stuffed animal.

Laugh

Well, it did FEEL like a little stuffed animal for a few days. Probably should've had it stitched up like a little stuffed animal.Embarrassed

BroadwayLion
I did not see the knife unitl I replied. I hought you were cutting the foam with the aeroplane.

That would've been safer, for sure. Lesson learned -- be carefull freehanding when cutting with a 14" knife. I slipped and didn't quite have the end of the thumb out of harm's way. Oooooooops.

Mike Lehman

Urbana, IL

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Posted by selector on Saturday, September 26, 2015 12:25 PM

I haven't shaped extruded insulation foam board for about ten years now, but when I did, I used a reversible blade utility knife, the kind where you slide a nub and the triangular blade also slides out of the front of the handle.

I used PL300 to glue it in stacks, but a cheaper DAP Alex Plus will also do a decent job.

For shaping the edges to form hillsides or gullies, or river beds, I used a wire brush and then sanded it with a foam sanding block.  Yup, it's very messy.  Have a shop vac nearby and get used to running the wand over your work area every couple of minutes to keep from dropping the bits of foam all over your layout and floor as you move around and kick them up.

If you don't mind the expense, and don't wish to fiddle with making a perfect foam hillside with no discernible stacking gaps, cover the face of your newly formed hillside with plaster cloth or spackle.  Spackle will be about half the cost, or even less unless you slather it on about 1/2" thick in most places.

One advantage of using spackle is that, while it is still wet and setting up, you can spray an adhesive over it, just a whiff, and then blow your mix of ground foam terrain covering or "soil" into place from a V-shaped piece of cardboard. It will stick and be firmly fixed in place once the spackle under it hardens.

Work smarter, not harder.  Timing is everything. Cool

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Posted by CGW121 on Saturday, September 26, 2015 3:29 PM

My thought was to make the basic shape withthe foam then cover it with plaster of paris carve the rock face and paint it. Normally I use screen wire under it but as I have very little room to work with on the back side I want to make it on the bench and drop it in place. The bluffs along the Mississippi are verticle and often fairly flat on top. I will just have to try different methods.

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Posted by mlehman on Saturday, September 26, 2015 4:34 PM

I'll offer a few suggestions, although you're on the right track here with your thinking by doing it off the layout and making it a drop-in.

If you haven't tried Sculptamold, it could help here. Carve your foam, but then apply a layer of Sculptamold, shaping it as you apply. It can be shaped and textured so long as it's wet. It sets up slowly and can be rewetted if need be to continue working it. It may take some experimentation if you haven't used it before, but it's a very forgiving material. Here's some Rocky Mtn style rocks.

I've used it to make "rock" but it's versatile enough to do things like snow, which is what I was doing when I hacked my thumb. Carved the basic form of the "snowcap", put it on the mountaintop with plastic wrap underneath , the applied and shaped the Sculptamold. This is what the bottom of it looks like (note bandaged thumb):

Sculptamold is much lighter than plaster once dry and is more durable as it doesn't crack or break like plaster might. It can be applied thin and still be strong.

If you have a very tight clearance issue, I suggest looking at Cripplebush RubberRocks. They're not cheap, but they are thin and look great. I used them for some very similar spots as it sounds like you're dealing with. They're the vertical rocks that separate the two levels in this pic.

Here it is partially lifted out. There's a styrofoam base/armature that the Rubberrocks are hot-glued to. Sculptamold is used to blend it in around the edges.

 

Mike Lehman

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Posted by rrinker on Sunday, September 27, 2015 9:50 PM

 For cutting large pieces for benchwork (not small chunks for hills and so forth), I used a putty knife and sharpened the long edge plus one side. Pulling the pointed edge throught he foam a few times, along a straight edge, allowed me to make clean snaps to make sections to fit in my benchwork sections. Since a full 2x8 piece didn;t fit very well in my car, I also took the putty knife and tape measure along when I bought foam, and cut it in the parking lot into convenient 2x4 sections that easily slipped in the car.

 Carving small bits out, I use a serrated steak knife (for a while we had a set of 7 in the kitchen...shhhhhhh!. But we now have a nice set of knives including a full set of 8 steak knives, so the 7 matching the one in my benchwork drawer are now pretty much surplus and never get out of the drawer anyway. I should maybe appropriate another so there is an even number left. We never have that many guests anyway).

                 --Randy


Modeling the Reading Railroad in the 1950's

 

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Posted by kasskaboose on Monday, September 28, 2015 8:43 AM

Like Penn, I also use a drywall saw to cut foam.  I tried a hot wire from a craft store and returned it.  Any extra pieces can get used for making hills,etc.  For large pieces, I cut with a handsaw.  Given that the small foam pieces get everywhere, I use a dry vac when all done. 

Securing foam is easy w/ liquid nails and now I read that hot glue also works. 

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Posted by SouthPenn on Monday, September 28, 2015 3:20 PM

An electric carving knife. This what they use in a fabric shop to cut the pink foam to size for the customer. Be very careful!

South Penn

South Penn
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Posted by vsmith on Tuesday, September 29, 2015 6:15 PM

Large construction snap-off knife

Woodland Scenics Hotwire foam tool

Foam Factory Hot Knife foam tool

That's all I have ever used to cut and shape the foam on 5 layouts to date. That's been using 2" thick Dow Blue foam, same thing as the pink stuff.

I like the results I get

   Have fun with your trains

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Posted by John Busby on Tuesday, October 6, 2015 6:15 AM

Hi all

A good quality bread knife works for me "NO" don't borrow SWMBO'S from the kitchine that could get you killedSad

A hotwire cutter also works.

You will need to skim the final hill with plaster or similar just to finish it off before final scenic treatment

regards John

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Posted by last mountain & eastern hogger on Saturday, October 10, 2015 2:18 PM

vsmith

Large construction snap-off knife

Woodland Scenics Hotwire foam tool

Foam Factory Hot Knife foam tool

That's all I have ever used to cut and shape the foam on 5 layouts to date. That's been using 2" thick Dow Blue foam, same thing as the pink stuff.

I like the results I get

V.Smith,   Is that blood on the lower portion of your mini layout ??  And was it from the snap off knife or the Hot wire Tool ??   I sure hope not.   Lol..

Johnboy out...............................

from Saskatchewan, in the Great White North.. 

We have met the enemy,  and he is us............ (Pogo)

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Posted by vsmith on Sunday, October 11, 2015 12:08 AM

last mountain & eastern hogger

 

 
vsmith

Large construction snap-off knife

Woodland Scenics Hotwire foam tool

Foam Factory Hot Knife foam tool

That's all I have ever used to cut and shape the foam on 5 layouts to date. That's been using 2" thick Dow Blue foam, same thing as the pink stuff.

 

I like the results I get

 

 

V.Smith,   Is that blood on the lower portion of your mini layout ??  And was it from the snap off knife or the Hot wire Tool ??   I sure hope not.   Lol..

Johnboy out...............................

 

LOL no not blood. It's actually spray foam insulation. It was a disaster when dry, I cut out as much as I could and applied spackling paste over it all. That's just the spray foam showing thru. Looks 100% better now.

   Have fun with your trains

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Posted by corsair on Friday, December 11, 2015 1:48 PM

Hi,

     I use the Woodland Scenics foam knife and it works great.

Clint

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Posted by eaglescout on Saturday, December 12, 2015 7:30 AM
Spray it every so often with anti-static spray to keep the small particles from sticking to everything.
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Posted by BigDaddy on Monday, February 8, 2016 5:25 PM

So if you have 2" thick foam, how deep do you have to score it, to get it to break cleanly.  Yes I did a search and that's why I'm bringing back this thread

Henry

COB Potomac & Northern

Shenandoah Valley

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