Creating a swaged hole in the bottom of a fuel tank.

This sounds like it might be a situation suited for aluminum braze to avoid
tooling up for the edge weld?

Todd


I am starting to build my center section fuel tank and need information
about how to swage holes in the bottom of the tank so that I can edge weld
the six fittings specified in the plans. Four of the fittings are finger
strainers and one is for the sight gauge. There is one more hole on the
top for the filler. As there are only six holes in three different
diameters, I was thinking about doing it using simple hand techniques
rather than expensive tooling.

Here is my idea. The tank is .090" 5052. I planned on drilling holes
(.180+flange dimension) undersize in the aluminum. Then centering the
holes over 3/8" steel plate with holes .180 oversize, then use a
polyethelene bossing hammer to swage the edge of the hole into the female
die hole. The holes in the female die would have the edges relieved to
accomodate a bend radius. It might be time consuming but educational.

Any advice or previous experience to share