In addition to the other comments - if you're soldering to something that can sink a lot of heat (a great big copper connector, or the ground plane on a circuit board), you will probably need a fairly broad tip. A finer tip can't transfer heat fast enough, so you end up having to hold it in contact for far too long to get hot enough to melt the solder and (counterintuitively) you end up melting plastic or overheating components. Doubly so if you've cranked up the heat to help.

[–] eagleeyedtiger@lemmy.nz 2 points 5 months ago

Good to know, I’m mainly looking at repairing a few things for now, but hoping to find some small hobby kits to practice on later on.

[–] FloofahNZ@lemmy.nz 3 points 5 months ago (1 children)

The key to good soldered joints is cleanliness, both the iron tip and the wires/terminals you are soldering.

The iron tip needs to be kept clean, typically by wiping the tip on a slightly damp sponge. Most iron stands include a sponge. Use multicore solder, this has the flux built-in. Once the iron has heated up clean the tip with fine emery paper, and tin the tip with a small touch of solder. Wipe the tip on the sponge.

Never carry molten solder on the tip of the iron, use the iron to heat the wire/connector and apply the solder to the joint. Remove a short length of the wire insulation, if it’s multi strand, twist and tin the end before assembling the joint.

The size of the iron depends on the size of the items you are soldering. Bigger connectors and wires will need a bigger iron.

Remember keep everything clean!!! A fibre-glass pencil works great for doing that.

[–] eagleeyedtiger@lemmy.nz 3 points 5 months ago (1 children)

Thanks!

I’m trying to solder a loose socket on a circuit board. There seems to be very little solder originally on it, which I believe was causing the issue I was having when trying to turn on the appliance. I did make sure to get 60/40 solder with rosin core, but I think it’s too big and would be easier if it was thinner. I think it was 1.6 mm.

Is one of those brass wool tip cleaners fine by itself, or do I need a sponge as well? I did manage to get a few different tip sizes, so I can play around and find which works better

[–] FloofahNZ@lemmy.nz 3 points 5 months ago (1 children)

It could be that the problem with the socket are the plated through holes in the PCB. The socket gets regular plugs/unplugs and that’ll move the socket and could break one or more of connections to the PCB. The connections to the socket are potentially on inner layers of the PCB, that might be tough to fix.

Bulk assembly of PCB’s is fully automated these days, the components are machine fitted and the whole board is then flow soldered.

The damp sponge will wipe away any burnt on resin from the bit. If you use thinner solder, say 0.8mm, you’ll need to use a smaller iron bit.

[–] eagleeyedtiger@lemmy.nz 3 points 5 months ago (1 children)

I'm not sure how to explain it, it's a power connector (I believe) on the inside of an oscillating fan but not the part that gets plugged in to the outisde. It's the 4 pin header type of plug if you know what I mean. So it stays plugged in all the time. Sorry I don't know all the terminology, I'm still trying to learn!

[–] FloofahNZ@lemmy.nz 3 points 5 months ago (1 children)

OK, that’s unlikely to be a high tech circuit board. Try simply resoldering the connector pins, I’m guessing there are 4, but that is a guess. Apply the clean iron tip to each pad in turn, and run a little fresh solder to them.

[–] eagleeyedtiger@lemmy.nz 3 points 5 months ago

Will give it a go this weekend!