Is there a real danger with toxic fumes cutting insulation foam with a hot wire or is WS claim of non-toxic just advertising?
Some of you have talked about carving rocks and cliffs directly in the foam. How about some specific dirrections. What tools, what strokes, how deep? My first experments were not good.
Art
Art:
I’m kind of new to foam as well. I’m assuming you’re using the pink or blue stuff . . .right?
I don’t use the hot wire - I do some rough shaping with a long, sharp blade (like a fully extended disposable boxcutter). I just whittle away at the stuff. You can then smooth things out a bit with a wire brush. This gives it a little texture too.
When using the wire brush I have the brush in one hand and the shopvac hose in the other - its a messy job without a vac.
After that I paint the surface with some Flex Paste. and then start the ground covering.
-slim
Art;
I’ve never cut foam with a hot knife, so I don’t know about the claims. I usually use either an X-acto knife or one of those 98-cent disposable thingies you can get at any hardware store. Mainly because though I use foam as a scenery base, i just use it to ‘build up’ the contours, then cover it with a shallow layer of crumpled newspaper and plaster cloth, then do the usual contouring with either Sculptamold or Hydrocal rock castings. That way, I’ve at least got a solid base to ‘plant’ those nifty Aggrojones’ evergreen trees.
Tom [:D]
How dangerous are those fumes really? The little pieces would sure be easier to cut in the train room than to chase out the the band saw with each one.
As with any other petrochemical, the fumes emitted by heating extruded foam CAN be a hazard (they emit cyanide, for one thing). But as with most any other household “danger”, it’s a bit overstated. Go ahead and cut the foam with a wire cutter if you want (I prefer using all hand tools), and make sure there’s a fan blowing in your direction and a couple of windows open.
For sedimentary rock (shale & sandstone especially) I prefer using a rough hacksaw blade for rough cutting, and a brass wire brush for final shaping and to cut in the layered effect. For other rock, just like with hand carving plaster, it’s sort of an art form. Since yu can’t really use dental picks like with plaster, I’d just use a SHARP utility knife and start cutting. Use fine (200 or finer) sandpaper to finish off the carvings and to remove sharp edges. And as with anything else in this hobby, it’s generally best if you have a few good reference photos sitting in front of you for inspiration.
The best way to learn? Just jump in and do it. Take a scrap piece of foam to your workbench, with a photo of an area you’d like to model. If you like the result, a little bit of Liquid Nails and your cliff in in place on your layout. You’ll get the hang of it pretty quickly and the foam will be flying in no time. Shop vacs and understanding wives: the neatest things ever invented by God.
Art,
I have done extensive foam cutting with hot wire tools. Just use a fan like stated above and you will be OK. Hot wire is sooo much better than any other way. No messy "sawdust " to clean up from everywhere. If it’s in your budget, the HOT WIRE FOAM FACTORY system is what I use. Several diferrent tools for many effects. I’ve made everthing from mountains to ditches and even stairs for an approach to a large building. With foam you can easily replace a section if you don’t like how it looks. Try it and I think you will agree.
Ray--------Great Northern fan.
This may simply be a ‘dumb rookie’ question, but I’ll ask it anyway…
What kind of paint can you use on the foam? I know some types of paint melt the foam, which is why I have been reluctant to try this method of cliff-building.
Thanks for your help!
Hacksaw blades work real well allso!
Paint questions…
You are right about the spray paint eating the foam. From what I have figured out, it is the propellent, or drying agent in the paint that causes the foam “eating” I have found two types of paint that work great though…
Both are Krylon family.
One is a brand called “Make it Suede” It comes in , luckily, earth colors and leaves a light feathery finish. But in order to get the “suede” finish, you have to use alot. I have always thrown down enough paint to get to color. A few different types of tans, browns.
The second is called “Make it Stone” This is another “finish paint” that gives your item a speckle coat. Works great for instant texture. They offer this in several different colors combonations as well. Use a base color then hit it with the speckle coat and bingo your done. I have great luck with this. I used the sand color texture to paint my whole industrail yard and you have too look hard to figure out that it is not actual sand glued to the foam. I think I have some pictures on my Web Shots link in the bottom of the post.
Both of these paints are 100% foam safe. Sprayed them on Blue and white, (white is what I use most of the time).
If there is enough intrest I can post some more pics on Web Shots to see how the stuff comes out.
Any hardware store shold have it. Good luck
John k
Don’t know about #1, don’t use the tool. As for the rest, I have had extremely good luck with running a 1/2" deep or so score along the foam, then placing the piece on a long enough table (or in my case-top of the chest freezer in the basement), and giving it a good whack. When the parts break apart, the pattern very closely resembles some of the rock formations I’ve seen on the California Zephyr between Helper and Salt Lake City. Oh, by the way, almost forgot, this works best on the 2" or thicker foam. For the finishing touch, depending on the position of the “cliffs” or whatever, I use various sizes of aquarium rock at the base to simulate rockslides. I use either a granite style or what they call “natural”, and if necessary, paint. Good Luck.
Latex, apply with brush or roller.
“Tippi Hot Foam Cutter” is the magical answer. It cuts beautifully with virtually no fumes!! It gets just hot enough to cut the foam. You control the heat via the trigger; heats quickly, needs little waiting time. “Just a little heat does it”. Different tips come with it. I got mine at the Raleigh GAT show; available at BCH Int’l, Johnstown,PA
ph 814-255-1650 or MALJST@ATLANTICBB.NET, on the web @ bigcityhobbies.com.
To SUSHOB: Use FOAMSEAL to seal the foam (also adds considerable strength) then paint with whatever you choose! Available from BCH Int’l,
ph 814-255-1650, email MALJST@ATLANTICBB.net[8D]
Wallychoochoo - Thanks. I knew something like that had to exist. I ordered one today. We will see how it works. If I learn how, I will post pics if the canyon looks ok. I think a little gouging and scraping with a knife will add the sharp detail that seems to be missing.
ARTHILL
Hot wire foam cutting tools most certainly CAN be used, I have used them with great success, what Woodland Scenics seels is the correct tool and they sell the polystyrene also. Here is a website that can give you much more info. If you want to find out even more, just do a search on the web, you can find out all you need to know, unbiased in most cases.
http://me.mit.edu/Lectures/SketchModelling/3.1.1-examples.html