In article ,
Jeff Liebermann wrote:

Yet, all the boards in my collection are quite straight. That
demonstrates that it can be done. I'm not sure what you're doing
that's wrong, but I agree with others that suggest you're using far to
much solder and heat. Smaller parts, less solder, and less heat will
help.

Incidentally, when I say less heat, I don't mean less temperature. I
use the hottest iron tip I can get away with, and work fast. That
minimizes the energy transfered to the solder joint and therefore
reduces the heat affected zone.

I think one problem is that this is a home made board. The holes are
likely too large for the components (because most people don't have very
small drills on hand or even the drill chuck to hold them) and obviously
they aren't plated through. That can make it necessary to glob on the
solder.

As far as temperature, I agree with you. I've never found a need to
solder anything at less than 800F. Smaller parts just require shorter
dwell time.

I have no idea why the OP is using such thin stock, though. It looks
like he'd have room for something as robust as .050".