Cutting Styrofoam

[Skeeziks]

How do you cut it without making it "Snow?"
I cut it with a coping saw and now the cut end won't stop snowing, no matter how much I keep wiping it away.
Is there a way of burnishing it to get it like the finished sides of the styrofoam?

 

[Smith357]

A hot wire cuts Styrofoam slick as a whistle. The only issue is making the setup to do it.

 

[m1gunner]

Use a hot wire to cut it. I normally use some .021 stainless steel safety wire and run 12 volts through it. It is plenty hot to cut the foam (like a hot knife through butter). It seals the cut, no snow.

 

[Skeeziks]

Could I just use a hot knife?

 

[hsguy]

If you have a lot to cut this may be worthwhile.
Hot Knife - Great Deals on hot knives at Harbor Freight

 

[HAWKEYE10]

I insulated the garage doors at one house I lived in. To cut the styrofoam I used a utility or box knife. I used the type of knife that you break off the blade to get another sharp edge. You can run those blades out pretty far so hopefully you can cut it in one pass. Don

 

[Skeeziks]

If you have a lot to cut this may be worthwhile.
Hot Knife - Great Deals on hot knives at Harbor Freight

No...actually right now I only have this 1 small piece to cut. But thanks.

 

[galleta loco]

Fillet knife what we used to use,when installing EFIS system.

 

[ancient-one]

A band saw will give it a really smooth cut but it will not seal like the original surface.

 

[venomballistics]

nichrome wire strung with tension works like a charm.
Ive used it extensively to cut wing cores for RC aircraft

 

[Class III]

Go to Filmhandlertools DOT com or a wallpaper/paint supply store and buy an Olfa Knife. It will run you around $6.00 bucks. It is a razor knive with the snap off replacement blades. Buy the Olfa Silver Cutter, or the Olfa Silver Cutter Auto Lock if you are left handed and it will last you a lifetime. I use them on a daily basis cutting window tint film. In 22 years I think I have bought maybe a dozen of the knives and several hundered packs of 50 count SS blades. I carry six of them at a time and most of the "Replacement" knives I've bought have been because I lost one. In 22 years I have managed to destroy only one. Hell, I even used one to field dress a deer when I forgot to bring the appropriate tool for the job.

And yes, I have used it to cut styrofoam with great results.

Class III

 

[Steve in Vermont]

Your wifes 8" stainless steel carving knife. But be sure to clean it well and return it to its exact storage location before she gets home.

 

[Maximumbob54]

I have run wire around a coping saw that I removed the blade from. I sat the wire on the top of my lead melting pot for a few seconds and it sliced right through Styrofoam like a laser. The wire I used was just from an old spool of leader wire. I don’t even remember what gauge it was.

 

[Stonecove]

The problem your having has more to do with the type of foam you are cutting. Open cell foam is made from beads and the only way to get a clean cut is to use a hot knife or hot wire. It is junk insulation and absorbs water too if thats important. Get some blue or pink board (extruded polystyrene) from Lowes and cut it with a knife- problem solved! Also does not absorb water.
Stonecove