Another Question About Cutting Foam

Discussion in 'FAQs' started by ScottyB, Feb 9, 2005.

  1. ScottyB

    ScottyB Member

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    Anyone who can help,

    Things are progressing well on my layout, but I have hit a snag. I am using 2" foam as a base and need to cut a downward grade into it. Kind of like a small canyon. It will not extend to the edge of the foam, just a 4" (or so) groove in the middle, where the sides are still at the 2" point.

    What is the best way of doing this? I know the WS Foam Cutter will do edges, but can it cut a groove down the middle as well?

    Thanks,
    Scott
  2. pomperaugrr

    pomperaugrr Member

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    I would recommend a sureform rasp. You can pick one up for less than $10. Try to get one with a curved blade. It should meet your needs. Just have a shop vac nearby, as it will leave some bits of foam dust that will cling to everything in sight. Just proceed slowly and check your measurements as you go. It is easier to remove more foam, than trying to add it back if you take off too much.

    Eric
  3. Matthyro

    Matthyro Will always be re-membered

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    Depending on the type of foam you are using. a good sharp kitchen knife will cut into the foam OK. I have also used a drywall saw to make cuts like this.
  4. ScottyB

    ScottyB Member

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    I think I didn't explain what I needed well enough. The groove in the middle of the foam will start at the top (2" elevation) and go down to a 1" elevation. But the edges will still be at 2". (Picture a biscuit slot perhaps) I have a hobby knife that works well, but not for this particular need.
  5. Doc Holliday

    Doc Holliday Member

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    Although I'm sure some of my fellow forumites will advise against it, I've (accidentally) cut similay slots in my 2" thick foam by being clumsly with my hot soldering iron. Just getting it close is enough to the foam will melt it, although it wold be hard to make an exact cut. It does give off some obnoxious fumes as well. I've played around a little using an old soldering gun like a WS foam cutter, wearing proper breathing protection in a well ventilated space. It worked great, but leaves a residue on the hot tip. No mess to clean up though.
    Doc
  6. billk

    billk Active Member

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    If you have a soldering gun (gun, not iron) with a removable tip - mine is held in with a couple of set screws - take out the tip and replace it with a loop of heavy bare copper wire, 10-12 AWG or so. The wire can be bent into the shape of the groove you want to cut. Keep the wire length as short as you can so the loops stays as stiff, and as hot, as possible.

    Viola - a custom hot wire groove cutter!

    When you're done, put the soldering tip back in and no one's the wiser.
  7. Doc Holliday

    Doc Holliday Member

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    Now why didn't I think of that?
    Doc
  8. ScottyB

    ScottyB Member

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    That's a great answer billk.

    Thanks a lot!
    Scott
  9. TinGoat

    TinGoat Ignorant know it all

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    Home made hot wire foam cutter.

    I built my own hot wire foam cutter from brass rod and ni-chrome wire.

    I cut grades into my modules with it.

    I put "shoes" on the brass rod to limit the depth of the cut and used a soldering iron to cut channels for the brass rod to follow.

    Then, I used the hot wire foam cutter like a plunge router...

    This is over-simplifying the process, but I was happy with the results..
  10. TrainClown

    TrainClown Member

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    I shape foam with no troubles and I use an ordinary wire brush. I just scratch away in one spot and the foam flies. Once I get to the basic shape I like, then I sand it smooth with 80 grit sand paper. This would be the cheapest and fastest way to cut your trench.



    TrainClown
  11. billk

    billk Active Member

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    The typical steel-bristled brush is sometimes a little too coarse and/or too big for this, but if you go to the plumbing department of a home improvement store, you can get smaller, brass-bristled brushes (I think they use them to clean pipe thread or something) that work really well.
  12. Kim Paynter

    Kim Paynter New Member

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    I gota aggree with Eric I like the rasp idea I got a small one. Has a rasping area of probably 1" X 1.5" and a little handle on it. About the size of a 2" paint brush. The one I got is made by Stanly.

    P.S. I also got the 2 handed model thats about the size of a hand plane and it's just to big for the job. but I love my small rasp.

    Kim

    P.S. neet idea regarding the custom hot wires but since it's winter where I live I can't get outside away from those nasty cancer causing vapors so I'm sticking with the rasp and shop vac.
  13. Kim Paynter

    Kim Paynter New Member

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    I gota aggree with Eric I like the rasp idea I got a small one. Has a rasping area of probably 1" X 1.5" and a little handle on it. About the size of a 2" paint brush. The one I got is made by Stanly.

    P.S. I also got the 2 handed model thats about the size of a hand plane and it's just to big for the job. but I love my small rasp.

    Kim

    P.S. neet idea regarding the custom hot wires but since it's winter where I live I can't get outside away from those nasty cancer causing vapors so I'm sticking with the rasp and shop vac.
  14. Will_annand

    Will_annand Active Member

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    To smooth out the rough areas, take your wife/daughter's hair dryer (or maybe yours, I don't know :D ) and melt the foam slightly.

    It tends to smooth out any rough cuts.
  15. ScottyB

    ScottyB Member

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    I like TrainClown's idea a lot. I tried the hot foam, but like Kim said, horrible fumes quickly filled the basement, so I abandoned that idea real fast.

    The wire brush I will have to try. And I need to look into the rasp. Thanks all for your great ideas!

    Scott
  16. TinGoat

    TinGoat Ignorant know it all

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    If you're not using a hot-wire foam cutter...

    Here's a suggestion...

    To avoid all the foam fuzzies from sticking to everything....

    I have heard that you can use a spray bottle full of water. Set it to spray a fine mist of water to dampen the foam.

    This neutralizes the static electricity and keeps the foam fuzzies from sticking to everything. :thumb: :thumb: :thumb:
  17. Matthyro

    Matthyro Will always be re-membered

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    That's a good tip TG. I will try it next time I am using foam.
  18. ScottyB

    ScottyB Member

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    I did this and it works wonders. Surprisingly very few fumes as well. Toughest part is getting the result somewhat level, but nothing a little sanding can't solve.

    Excellent suggestion!
    Scott