Well thanks for the reply's, can I ask what the risk is when using this stuff with smd parts? Is it going to cause corrosion over time? The stuff said it will solder with a match on the label I tried to spread it on two pieces of 6ga wire and use a butane heat gun to get it soldering I ended up having to use the iron in the end, so not as impressive as there pitch, I will stick with my leaded silver bearing solder for most things but thought this stuff may work well for QFNs with a heat gun.