Weight saving exercise.

ORVAL FAIRBAIRN
sednews
In article ,
Matt Whiting wrote:

Fortunat1 wrote:
"Cy Galley"
sednews:4V41e.103754$r55.32258@attbi_s52:


I would check with a Van's builder. RVs have aluminum riveted tanks
with pro-seal. If you know a good tig welder, then a welded tank
can be built.



OK, thanks.There are two down the road from me, in fact! I'll
probably try and weld it myself, though I've never welded aluminum
before. Then again, most ofthe things I've done on this contraption
I've never done before. I'm assuming baffles (and I think I'd
need them in a long shallow wing tank) aren't welded, though. I'm
supposing that the tank would be assembled, but the back left open
until the baffles are all riveted, and then closed up and welded?

I see no reason not to weld the baffles as well. Probably less messy
than sealing the rivets.

Matt


that depends on the aluminum alloy used -- and, how much warping you
can tolerate. Van's tanks are "wet" cells -- part of the wing and are
2024-T3, which is NOT weldable. The nice thing about wet cells is that
they add only the weight of the ProSeal to the airframe weight, while
separate tanks add their own weight to the plane.

6061 and 5052 are common weldable alloys, but you will get some
distortions from the welding process.

I still don't see how I would weld the baffles in place before the tank is
closed up. This tank would be about 48" by 24" by 5" The top has a bevel at
the back to conform to an airfoil shape. I reckon I'd need two baffles
(strictly eyeball engineering here) to minimize sloshing from side to side.
maybe just one. If I were to make the tank out of a single wrapped piece
with ends stitched on afterwards, how would i go about welding the baffles
in place? Put the ends on last? Presumably, the baffles would only need to
be tacked as opposed to a continuous seam all the way around..