as it happens this is something I've messed around with - I made a heater using a piece of stripboard - I didn't coat the strips and I ran 10 volts at 2.5 amps through it which made it warm up as intended but didn't burn up any strips
if you coat the "high energy" strips with solder then you should happily be able to handle 3 amps maybe more
www.paulinthelab.com - Stripboard Layouts