Soldering help

I am having real trouble soldering the six pins on the teensy for the ethernet connection. I bought a cheap soldering iron from ebay but just cant seem to get any heat into the pcb. Im tinning the tip first but still struggle to get any heat into the pcb to get the solder to run down.

Here is a link to the soldering iron I purchased:

Has anyone got any suggestions or a link to a soldering iron they have been successful with?

Clean the tip often( with scotch brite), it oxidises fast, put some solder on the tip first as a conductor and then try heating the wire. The iron is plenty powerfull, is the tip mounted properly?

I think what you are missing, is solder paste. It helps leading heat to the small pads.
One example! Solder paste 20g AG |

I have never tried that iron but it should work. Like it was said above make sure your tip is cleaned and that you are using a good flux core solder. You didn’t say what solder you are using but some of the cheaper ones don’t flow very good. You might try a different solder.

I adjust the pins with the black plastic flush with the Teensy and this way it is easier for the solder to stick.

Kester rosin core solder is worth the cash, something very thin like 0.75mm Sn60Pb40.
Leaded rosin core solder in very easy to solder, lead free takes a bit more heat.
Rosin core solder does not require flux bonding new parts. Flux is handy for repairs to float out impurities, or make solder chase through tight areas.

Use the most needle like end that came with your kit, let it warm up with ample time. Make sure the solder instantly melts when it touches the tip. Make sure the tip is wiped free of previous solder and rosin.

Place the tip on the parts to be soldered for 3s, then dab the solder onto the tip it should flow into the joint then remove the heat.

Be patient and allow the teensy to cool a bit between pins.

There are definite differences between plumbing, electrical, and electronic solders and flux. Canadian tire sells “electronic solder” under the “electrisol” brand that is the most infuriating and hardest to use ive ever encountered.