Soldering on household 12V Halogen

Hey people

I just thought I'd ask you for a piece of advice... I'm trying to make an alternative flashlight using 12V Halogen bulbs. Its been tested to work, but apparently only the first of my bulbs was solderable. I tried ramping up the heat on my iron to 400 deg, just to see if it was a heat-issue, but it does not appear so.
Do any of you have a clue how to solder the pins on these standard bulbs (G4 types and the other 12V types with built-in focusing mirrors.. The boxes don't show their names)?
If you know of alternative solutions for securing these bulbs mechanically, you're also welcome to write.

Thanks in advance.
/Pax

Why not use the socket that is designed for them? Remeve the sockets from a lighting fixture.

Maybe you could find a screw terminal wires connector with the terminals at the correct distance apart then just tighten the screws on its pins if they don't melt it.

Use one of these:

http://superbrightleds.com/specs/mr-socket.htm

Thanks guys. I think you're right, that the only solution is to use a socket - It'll make it much easier to replace the bulb when it blows anyway. I'll pick one up today.

Have a great day

/Pax