I have read responses to threads that mention the foaming urethane glue. Some love it others would never use it. (Is that different from anything else?) The one time I did use it the bubbles formed (from Carbon Dioxide formed during the curing process I'm told) would seem to indicate that large gaps need to be totally eliminated. I emailed the manufacturer of one brand and the response was not to use it anywhere it would come in contact with fuel of any kind. I would like general opinions on whether to use it or not and how. What is your experience?