Spike,
First off the SMT line of solder guns are nothing but small heat blowers that are extremely overpriced. . Understanding that you can by a plastic welder from Harbor Freight, and a small aquarium pump and make your own SMT Solder Gun. I used the 30 dollar model and used a piece of copper tube to reduce the size that blows the heat out. It is very easy to use when you have only a few parts to put on a board or if you ever have to replace any SMT components.
Ok, if you have a lot of SMT components to place on a board you can put them on and the paste solder will hold them in place as you work the heat around. If you want to work a board full of SMT Components this might be better. You will need a small toaster oven, but a big oven will work if you don't have the smaller one. First you place the paste and components in place, then carefully, very carefully place the board in the toaster oven. Recheck to see if all the components are in place, and if they are close the door and turn the oven up to around 400 degrees. You really need to check what degree mark you will need to turn the oven up to in order to melt the solder paste before you do this on an actual board, but do use a junk board while checking as other material may give you false indications. Once you know what to expect you can do it for real. When doing it for real watch the board through the window and when you see all the joints are shinny give it about 3 more minutes, then carefully cut the power off and open the door. Make certain that you do not jar it around or the parts will move. Believe me they move a lot easier than you would think. Let it cool down while you have a cup of coffee or a coke.
If you go out to buy a toaster oven try to get one that has overhead heating wires or elements. They work the best because the heat is forced down onto the PC Board.
Anyway that is my 2 cents worth and I hope it helps you out. You or anyone else.
