Soldering in new small caps

[Geoffreybombom]

I’ve removed 20 small caps from my amp, new Nichicon caps have arrived, any tips on soldering them in would be very welcome. Thanks.

 

[Retro]

Hi G,
Your question is as broad as it's long, so many variables. However, I would focus on the following.
Don't use a high wattage iron. Unless it is temp controlled 18-25watts.
Use normal 60/40 solder. The ones containing silver sound like they should be better but it does not flow as well.
Keep the iron tip clean, use a sponge or such like.
Insert the component (observe polarity). I always scrape the component legs with a Stanley blade to ensure they are clean and bright.
Hold the iron against the PCB pad and the component leg (at the same time) and wait for 1-2 seconds before applying solder. Hopefully, the solder will flow around the joint. Clip the component leg. If the joint is big or the PCB tracks are heavy you may need to keep the iron on a little longer to get some heat into it. If it seems a little reluctant to warm up, melt a little solder on the iron tip which helps to increase the contact area and get some heat in.
I usually clean off the finished joints with an old toothbrush and some spray ethanol to clean off the claggy flux remnants. There are a lot of how to videos on YouTube and if you watch one of those and keep the above in mind, you'll be fine.

 

[chartz]

The obvious question being: what did you use to unsolder the old caps?
I use acetone to clean the board before soldering the new components. I like a clean PCB.
Remove the excess of solder with a braid.

 

[davidsrsb]

Don't use a high wattage iron. Unless it is temp controlled 18-25watts.

I disagree, a more powerful eg 60W temperature controlled iron will solder to ground and power planes much better and cannot do harm.
Under powered irons take too long to make the joint. I have a Pro'sKit 60W workstation

 

[chiily]

The obvious question being: what did you use to unsolder the old caps?
I use acetone to clean the board before soldering the new components. I like a clean PCB.
Remove the excess of solder with a braid.

I was going to add this to @Retro post, all good advice, especially when working on old (50 to 60 yo) solder joints.

 

[Geoffreybombom]

I used my small tip soldering iron to remove the caps, however I guess that was the easy bit, I just wanted advice on the hard bit, soldering the new ones. Thanks for the replys.

 

[Mike P]

Dress the leads properly if the pitch of the PCB holes doesn't match that of the caps.

I often use blutac to hold caps in place so that I can flip the board over for soldering.

 

[Geoffreybombom]

Blutac is a good tip, do you use flux, thanks.

 

[Mike P]

Blutac is a good tip, do you use flux, thanks.

I don't use flux for most new components, the flux cored solder is sufficient. I will sometimes use flux for IC's or old stock components with slightly oxidized leads etc.

As others have said upthread, get some 60/40 tin lead flux cored solder.

 

[Geoffreybombom]

Ok, thank you.

 

[Gervais Cote]

And make sure the polarity is okay.

 

[Geoffreybombom]

Thank you