I have made and given close to a hundred of these potato bags. Have only had one instance where it caught fire and that was me checking to see if the thread would make a difference (the problem happened because I put the bag in there empty - think that made the difference). Yep, I had used cotton covered poly thread and as I was standing right there I caught it just as it started to smoke. I love my potato bag, have even continued to use the one that the seam burned. Some people don't realize that a lot of cotton thread is really cotton covered poly. You have to make absolutely sure that everything is cotton. My microwave is one of the high powered ones.
Last edited by renda; 10-03-2017 at 03:25 AM.
Reason: not enough info.