Soldering help...

[drissa]

Hi

Some soldering questions:

1. I bought a decent iron, but the tip is still losing heat. Even on full power (something like 30w) I'm having difficulty just melting solder. It seems to get blackened pretty quickly, but I don't see how this can be avoided. I have a battery powered iron with a larger tip - this is much better, but holding the button in and waiting for it to heat makes it impractical.

Any tips?

2. How do I solder wires to the connection 'posts' of pots/switches? They don't seem to hold any solder, so I can't tin them. The wire just dangles off and causes bad connections. I'm sure I shouldn't be relying on my glue gun so much...

3. Those little bits which stick out of pots are annoying! I assume they are to help locate the pot and stop it from turning when the knob is rotated. I'm afraid I lost patience and used the iron to melt a hold for them in the side of the toy, but I'm sure there is a better way... Any thoughts?

Many thanks

[Circuitbenders]

1: it sounds to me like you need a new soldering iron tip. Lots of things can damage an iron tip but not cleaning it and using it to melt holes in plastic will cause a dirty oxidized surface and cold spots very quickly. Theres some tips on soldering iron care here http://www.inlandcraft.com/Uguides/tipcare.htm

2: Make sure you heat the actual connection tag before attempting to apply solder and try to melt the solder using the tag itself rather than the soldering iron, or apply the solder to the exact join between the iron and the tag if its a big one that could conduct heat away quickly. Put the soldering iron on the connection, wait for about half a second depending on the power of your iron, and then apply the solder to the connection tag with the iron still in contact and you should see the solder 'flow' onto the connection. You will find that if you heat the connection tag for too long things start to melt on some switches so be careful. After a while you get a feel for it and it becomes second nature.

3: Snap them off with a pair of pliers.

[drissa]

Thanks. Will keep practicing.

[kick52]

3. Yup, I snap those bitches right off with my wire strippers.

[Gordonjcp]

1) sounds like the tip is getting manky - wipe it on a damp sponge or even damp tissue paper

2) sounds like you're not heating the solder tag up properly and getting the solder to "wet" it before making the connection

3) I drill a wee hole for the tag to go into.  If I'm mounting it on plastic I don't drill all the way through, but metal is usually too thin for this so I just make sure the knob is big enough to cover it up.

[drissa]

Thanks for advice folks. I'm learning more about soldering iron care. I'm not sure how it's possible to tin them, as suggested on various sites. I can't really get any solder to adhere to the end - it just 'beads' and runs off. I've given the tip a good seeing to with sand paper and this has shifted the black stuff. Will try again...

[kick52]

Try scraping the tip gently with a sharp knife to get off any crap. It may be rusty. (even if you can't see it)