Pre-heating your Mobo
I have arrived at a novel but effective way of preheating motherboards before attempting soldering work. This negates the need to purchase a $700 factory convection unit which a salesman tried to sell to me.
You take 2 common house bricks and an old shirt made of non-flamable material. You position the bricks about 300mm apart and cover them with the shirt. Then tuck the ends in under the bricks.
You then place the outlet of a hair dryer under one side, wrapping the material around the outlet to prevent air escaping.
Place your mobo on top of the shirt so that it sits between the housebricks weighing down on the material. Turn on the hair dryer and pump hot air into the enclosure.
The hot air is forced evenly and gently upwards through the shirt material and after a few minutes the PCB is nice and hot making desoldering much easier.
You can repeat this as required to maintain temperature or focus the hair dryer on the working area of the PCB to maintain heat when addressing stubborn joints. The more stubborn the joint, the more I heat the surrounding copper landmass with the hot air stream rather than using the soldering iron which may cause damage if applied too long.
Before desoldering, I also first pretend that I am soldering the joint, adding plenty of fresh new solder to it. This was originally suggested by Topcat and makes a big difference when desoldering those stubborn joints. The fresh new solder seems to meld with the old solder making it flow much easier.
This has helped me greatly reduce the likelyhood of failures when recapping.
You take 2 common house bricks and an old shirt made of non-flamable material. You position the bricks about 300mm apart and cover them with the shirt. Then tuck the ends in under the bricks.
You then place the outlet of a hair dryer under one side, wrapping the material around the outlet to prevent air escaping.
Place your mobo on top of the shirt so that it sits between the housebricks weighing down on the material. Turn on the hair dryer and pump hot air into the enclosure.
The hot air is forced evenly and gently upwards through the shirt material and after a few minutes the PCB is nice and hot making desoldering much easier.
You can repeat this as required to maintain temperature or focus the hair dryer on the working area of the PCB to maintain heat when addressing stubborn joints. The more stubborn the joint, the more I heat the surrounding copper landmass with the hot air stream rather than using the soldering iron which may cause damage if applied too long.
Before desoldering, I also first pretend that I am soldering the joint, adding plenty of fresh new solder to it. This was originally suggested by Topcat and makes a big difference when desoldering those stubborn joints. The fresh new solder seems to meld with the old solder making it flow much easier.
This has helped me greatly reduce the likelyhood of failures when recapping.