A lot of kayaks are used in fast flowing water. If a Al yak hit a rock or tree, it is more likely to fold.
Also, a metal boat will tranmit heat too well. Kayak is different from a canoe -- you need to sit low. Imagine the Intuit paddle that between the iceberg.
In other words, we have much better material for a kayak, Why Al?

: This may sound like heresy but I was wondering why an aluminum kayak would
: not be feasible.

: I have made a CLC stitch and glue and my idea is to cut aluminum sheet panels
: as is done in a stitch and glue and weld them together.

: I have the necessary welding and sheet metal equipment.

: Does this make any sense or am I missing something?

: What problems do you anticipate? I live in Southern California so the lack of
: insulation from the water should not be a big problem.

: Happy Holidays!