(De)Soldering for Beginners - Need help [Photos]

[BlackVirus]

 

Hi all,

I've been trying to get into soldering this year, and I've pretty much ordered everything needed for this mission.

Been watching countless videos on YouTube and read articles and thought I practice on an old motherboard - by removing capacitors (?)I think that's what you call them? (see pics)

 

Since they're already soldered onto the board, I'd have to desolder it to loosen it up a bit.

So i used a desoldering braid with my soldering iron at 325°C. I've also added some flux. 

 

Nothing is happening. The braid gets warm, but it's not sucking up the solder. The solder from the board is not liquidizing. Am I using the wrong tip or the wrong temperature or bad brands ? Hopefully the attached pictures can help you answer me   

 

thanks!

[SorryBella]

2 minutes ago, BlackVirus said:

Nothing is happening. The braid gets warm, but it's not sucking up the solder

No, you need an actual desoldering pen to do that.

 

[bmx6454]

can be done with braid, but de soldering pen would be easier. sometimes adding a bit of fresh leaded solder to the joint will make it easier to melt and remove.

[minibois]

There are mainly two types of components in regards to soldering; SMD and THT. SMD or THT, which stand of surface mount device and through hole technology.

As the names imply, SMD are soldered to the surface of the board using pads, while THT components have legs that stick through the board and are soldered in place like that.

What you are trying to desolder is a capacitor indeed, of the THT variety. While desoldering braid works very well for SMD, THT is typically easier done with a desoldering pump like what @SorryClaireshowed.

You first heat the solder, then the pump sucks away the now liquid state solder, which can lead to very clean desolder jobs.

 

Due to various reasons (such as environmental reasons), most devices will use soldertin with no lead. Solder with lead is easier to work with*, due to its lower temperature of becoming liquid. If you have some leaded soldertin, it is usually recommended to heat up the solder joint and add some leaded soldertin, to make the entire joint turn liquid quicker.

So my general workflow with removing a THT component is:

1. Add some leaded solder

2. Heat the joint and suck away the soldertin using a pump

3. Repeat step 2. until the component is free to remove and move to the next leg(s)

*lead can be dangerous, just like the fumes that come free while soldering. Make sure you're in a well-ventilated area and clean your hands after soldering.

 

Soldering braid is a bunch of copper wires braided together, infused with some flux. The braid will make it so the soldertin has some place to infuse into the braid, while the flux aids in 'attracting' the tin. It often helps to add some flux to the board when desoldering, especially because the flux further down in the braid can be evaporated by the time you reach that part of the braid.

Usually it's recommend to add a bit of solder to the end of your iron's tip, that just aids in the efficient tranfers of heat between your iron and the braid.

So my basic use with soldering braid (which I mostly use for SMD, or removing some residual soldertin) involves:

1. Add some fresh leaded solder

2. Add some flux to the joint

3. Add some tin to the end of my soldering iron

4. touch the braid to the joint, then the "soldertin added side" of the iron's tip to the braid

 

These are just some general workflow patterns I prefer to use, feel free to experiment.

The temperature of your iron should honestly be fine for leaded solder or just soldering in general, but unleaded solder can just be a pain to work with.

Another general tip, if you're done soldering add a bunch of soldertin to your iron's tip, that adds a type of layer of 'coating' to the iron's tip, since the tip could either oxidize (rust) pretty quickly.

 

Hope some of these tips help you! Great idea of starting with a 'practice board', so you get the hang of soldering before attempting to work on other projects  

[Levent]

Starting on a copper heavy consumer motherboard is not the correct way to go. These are not easy to desolder from. Dont waste any time and effort on this board, get DIY kits from ebay and start from basics.

[minibois]

2 minutes ago, Levent said:

Starting on a copper heavy consumer motherboard is not the correct way to go.

That's a great point to mention, this capacitor is connected to something (likely positive voltage), but also to ground (GND for short):

 

That might explain this point:

43 minutes ago, BlackVirus said:

The solder from the board is not liquidizing.

Simply put, a PCB consists of fibreglass, with layer(s) of copper adhered to it. This copper is removed in some places to make the traces, which connect the different components together. One of the most common connection point for these devices is ground (or GND for short). This capacitor is also connected to ground.

The copper on the board and the components attached to it act like a heatsink, soaking up the heat in the copper/components. A component that has a legs only attached to itself and maybe one/two other components heat up rather quickly, but a component attached to ground (or a similarly large area) will have a lot of copper on the PCB and components to soak up the heat from your soldering iron.

 

One of the legs of the capacitor - the ground leg - will be extremely difficult/time consuming to heat up entirely, because of all the heatsoak ability of the copper/rest of the components.

It might be easier to look for a component to desolder that isn't attached to ground; but those are rather uncommon. Ground connections can be recognized by the large connection points (the lighter blue) on the board. Large connection points could also be a positive voltage line though, which still have a large network attached; just often not as large as ground.

 

TL;DR: one of the legs on the capacitor has a lot of copper attached to it, so is difficult to heat up entirely.

10 minutes ago, Levent said:

get DIY kits from ebay and start from basics.

While I agree this is a great idea for someone wanting to learn how to solder, these kits don't teach you how to desolder though, that is what donor boards are great for.