SMT Hot Air Reflow Soldering Gun

Got hot air?

I just fabricated this hot-air soldering gun for about $25.  That's a far cry from the $400-$500 rework stations that we all drool over.  But it works great!   I have to admit it wasn't my idea... I got the inspiration from this website.

The iron is a $10.49 Radio Shack 45W Desoldering Iron.  I removed the bulb and replaced it with a hose attached to a fish tank air pump.  You don't need a lot of air flow so I stuffed the chamber that the tip screws into with a fine steel wool to slow down the air flow a bit and to allow more surface area to heat the air as it flows by. 

Preliminary testing (using a thermocouple) gave me a temperature of nearly 400 degrees F, which is ample to melt SMT solder paste which has a melting point of around 360 degrees F.   I'm still waiting for a tube of solder paste, but I can easily melt conventional solder with the device.

Hot air is one method of soldering tiny surface-mount components to a circuit board.  The components are so small that it's difficult to use a conventional soldering iron on them.   The photo to the left is a circuit board from a USB flash drive to give an idea how small the SMT components are.  Notice the partial view of the USB plug on the right side of the picture.  Them're some itty-bitty components!