flux / soldering paste..

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Well, those are two very different soldering tasks. Paste is normally used for soldering SMT components with a reflow oven, though it can be used with a soldering iron as well. Most other soldering in electronics can be done using rosin core solder, which has the flux inside.

Bob

 

Solder normally has flux inside. It is used to clean the part being soldered and to prevent oxides forming. It will not join the two parts together. You need solder for this, flux alone is not a solder. Flux is very good at making solder joints or for tinning wires. I often dip my bare wires into the flux then apply some solder. But normally a decent solder will have flux inside so you dont have to worry about it.
Adam

 

Solder paste is what is being used in the first video. You will need to Google this yourself. There are lots of different types out there. I am not going to link to one for you sorry.

Adam

 

As @(*steve*) noted, not everything labeled as "solder paste" (especially if it originates in China) actually has solder particles in it. And those that do contain solder particles vary widely in composition. In your first video, an excellent presentation of SMT re-work using a sub-heater under the PCB to heat-condition multi-layers, and a hot-air pencil to actually melt and re-flow the solder paste, there is no mention of the paste composition. Most SMT components are originally soldered using lead-free solder to comply with Euro RoHS standards. You can re-solder with a eutectic 63% Sn-37% Pb alloy or a 60% Sn-40% Pb (nearly eutectic) alloy that melts at a lower temperature and produces IMO a better joint. The problem is finding real solder paste with the desired composition. Here is a website to get you started with a lead-free solder alloy paste you can apply from a syringe.

Beware of the Chinese solder flux shown in your second video. Who knows what its composition is? It could be highly active but leave a corrosive deposit. Some of this stuff was made for tin-smith soldering and has been re-packaged as "electronic solder flux". Unless you can verify that it contains pure rosin flux, it is best to avoid this stuff.

Not everything "made in China" is bad. Amtech is a multi-national firm that makes both flux and solder paste, leaded and lead-free, at factories in Asia and Europe. Here is a link to their product line. Problem is, their target customers are large PCB fabricators who use the flux and solder paste in huge quantities. It can be difficult finding an authorized distributor who will stock and sell in small quantities syringes of the Amtech product (if that is what you want) and guarantee it isn't an Asian counterfeit.

I really envy you if you can afford to purchase the hot-air SMT re-work system shown in the first video. That's the cat's meow for SMT work! Most of us here use a pencil iron, tweezers, and a magnifying headset to solder a few pins at a time.

 

I have this bargain priced soldering station and I am very happy with it for both SMT and through hole work.

http://www.ebay.com/itm/2in1-898D-S...454?pt=LH_DefaultDomain_0&hash=item486ed3ef66

By the way, can anyone tell me what the little forked wire thing in the picture is? I got one of these with the station and I have no clue what it is for.

Bob

 

Maybe you loosen the screw and adjust the spacing of the prongs to be slightly less than the length of the part you are trying to remove. Tighten the screw and place the prongs on the device, allowing them to spread slightly so as to provide a "spring" grip. Now heat the part with the hot-air gun and (hopefully) lift it from the PCB when the solder melts. Or throw it away and get a vacuum pick.