I found two asphalt patching products online that are designed to be heated in the microwave. Both are out of stock. Can I heat up ordinary "cold patch" or "trowel patch" in the microwave?

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    Only if you are not married (or otherwise sharing a living space), or not planning to stay that way, IMHO. Perhaps if you have a "garage microwave" for crazy non-food uses. Boil some water and put it in a bucket outside (then put the container of cold patch in the bucket of hot water) seems far less likely to irritate other uses of the microwave. Mmmm... tar-flavored microwave popcorn.
    – Ecnerwal
    Apr 14, 2019 at 17:06
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    Oh boy, how to get to sleep on the couch in one easy move :)
    – Solar Mike
    Apr 14, 2019 at 17:52
  • @Ecnerwal - But the two products seemed to work great after microwaving. I wonder what the ingredients are? The think I know one should never microwave is metal. I wonder if regular cold patch contains anything metallic. Apr 15, 2019 at 0:44
  • The problem is not just that the patch might not heat up properly, or damage the microwave, but that it may leave residue behind in a microwave that you then use for food. Even if it doesn't leave behind traces of some horrible chemical, there's a good chance that the smell will linger on, and make your food taste like hot asphalt for a few weeks. Apr 16, 2019 at 6:15

1 Answer 1


Microwaves work by exciting the molecules in liquids that then trasfer their heat into surrounding materials. To be safe, "microwavable" products have water in them so that the water molecules are what heats up. If you use a product not designed for this, you could end up volatizing (vaporizing) VOCs (Volatile Organic Compounds) that are not only harmful, but potentially FLAMMABLE!

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