Hi Tom,

I was quite serious about my comment about using an old pool liner for all kinds of stuff. A friend of mine heat welded a lage pond liner together from a couple of old pool liners.

The words "safety critical" in this instance (IMHO) boils down to how confident am I about my workmanship/end product. That is a decision everyone has to make of all of their equipment, homemade or commercial. In my experince just because I've bought an item made by someone else doesn't guarantee quality.

Sorry for being so philosophical about all of this but you do raise an important issue. Airbags are a critical safety item and if you do make your own, you had better make sure it will work as expected when the chips are down!

Matthew