Dave,

Its hard to tell what a little springy or drum head tight is from reading something.

I can tell you I never got drum head tight on 6 boats.

You probably have some excess from the cutoffs, how about making a 1x2 frame, tacking the cloth on it and trying to see if you can get it tighter. That way you will practice with something other than your boat.

I tried to use an iron and the recommended temperature (240f) if I remember, and it seemed a little looser than I got with a hot air gun. But a few times I melted a previous boat skin (locally - quarter size spot) with the gun, you have to be careful, but I could never see a visual indication I was about to start melting.

The cloth will flex enough either tight or loose that you need to use flexible paint - I suggest outdoor oil based house paint - and I suggest NOT boat paint. The boat paint was brittle enough that someone check the skin by pressing hard on it and cracked the paint every 1' along the length. Now it needs a new skin.