How to you cut out excess expanding foam?

Posted on December 10, 2009 by admin

I used polyurethane expanding foam to block the space between the wall and the pipes under my kitchen sink (I have a mice problem).

Now there’s a big mass of foam around my pipes and I understand I have to remove it mechanically.

What is the best way to remove the excess foam without pulling out the whole piece of foam (and having to do it all over again).

What tool would you use for that?

Knife? (what kind)
Exacto?
Saw?

depending on the space you have to work in I use a small hack saw or small saw, then finish off with a bit of sand paper if you are so inclined

A knife or exacto will make you bleed :-)

Good Luck

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10 Responses to How to you cut out excess expanding foam?

  1. rmisbach says:
    December 10, 2009 at 5:22 pm

    use a hack saw blade without the saw. cuts easy watch out for pipes
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  2. disco legend zeke says:
    December 10, 2009 at 5:29 pm

    If you have one, try an electric knife, i have found they are perfect for cutting foam rubber, not quite as good for stiff foams.

    If you don’t have an electric knife, a serrated knife or hacksaw blade would work, but not make such a clean cut.

    Wear breathing protection when cutting.

    If you end up re-foaming, make a barrier out of plastic or cardboard to prevent the foam from expanding into areas where you don’t want it..
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    experience

  3. Iain N says:
    December 10, 2009 at 5:56 pm

    Some kind of serrated knife is the best. I used a bread knife when I did a similar job in my bathroom. Wetting the blade helps.
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  4. mrinternet says:
    December 10, 2009 at 6:41 pm

    depending on the space you have to work in I use a small hack saw or small saw, then finish off with a bit of sand paper if you are so inclined

    A knife or exacto will make you bleed :-)

    Good Luck
    References :

  5. In The Woods says:
    December 10, 2009 at 6:58 pm

    Just about any knife will do. I usually go at it with a razor.
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  6. jepa8196 says:
    December 10, 2009 at 7:26 pm

    Heat up a putty knife and the knife will slide right into the foam
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  7. Jeffrey S says:
    December 10, 2009 at 8:04 pm

    Good gravy man, it’s just foam. Grab the knife and hack off the excess.
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  8. thewrangler_sw says:
    December 10, 2009 at 8:43 pm

    Ive found that a simple hacksaw blade, just by itself works well, but in very tight fitting spots…. Fishing Line!… you can cut the foam with a length of fishing line pretty easy, and its handy to wrap around the pipes, to cut with, if you have no room for the hacksaw blade.

    Have Fun!
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  9. jeremy_hancock says:
    December 10, 2009 at 8:50 pm

    I’ve always used a razor blade or utility knife. The foam is fairly easy to cut whatever you use.
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  10. cossette_les_mis says:
    December 10, 2009 at 9:19 pm

    razor blade knife works best in my experience
    References :