The basics of proper soldering

What is the "right" technique to use for soldering?

I've heard several times that you should not put solder on the tip of your iron and then place it on your connection. Is that just because you want the connection point to be warm as well for a better bond? I'm told that you should hold your tip to the connection and then touch the solder to it. Is this the best way and are there any downfalls to putting solder on your tip first?

Thanks

Bryan

Sweet, thank you

It's fine to keep the tip tinned though, with a fresh very thin film of solder. Just don't go in with a big blob. Make it a habit to keep a moist sponge handy and wipe the tip before each and every soldering operation. One of the nasties in soldering is that the flux (rosin please!!---avoid "organic" or so-called "no-clean" flux at all costs!) will carbonize and contaminate joints. You leave a flux residue on the tip after the operation and it has time to degrade while the iron is idle. For the solder alloy, Sn 63 Pb 37 freezes "at once" and is generally preferred for this work.

Look for a convincing metallurgical bond after the operation. If the surfaces look dull and mottled rather than shiny you probably don't have a very good joint. Don't be afraid to wiggle things a bit well after the joint has cooled and look for telltale independent motions of the conductors that are supposed to be a solid ensemble. The folks who solder for aerospace sometimes are trained for months, so don't expect things to be perfect at first.

Now if I could only see what the hell I am soldering as in the days of my youth...

I don't really have any authority, but I'll tell you that getting a temp. controlled station has changed everything. I've been a hamptone/7th circle kit dork for a couple years, with a cheap weller.

I finally took the plunge and got a hakko 936 w/907 iron for $70 and I'm never looking back. It heats up in less than 30 seconds. The sponge has a built in mechanism, using a water tray, to keep it wet. It's really easy to clean the blobs.

Ultimately, my soldering looks about 70 percent better since I got it. I'll save in the long run not screwing things up...that's my theory, anyway. That, and it just makes things about 50 times more enjoyable...

kelly

Now if I could only see what the hell I am soldering as in the days of my youth...

Click to expand...

Amen!

:guinness:

getting a temp. controlled station has changed everything

Click to expand...

I agree. My weller temp controled has made soldering easy.
The more you do the better you get just keep at it....

oh I almost forgot...

Remember to put to cover on b4 solder the connection. There are countless number of times I am like Doh! It's annoying to connect the XLR/1/4 neutrik only to have to un do it so I can get the cover on. :evil:

Ha! I've done that heaps of times... Finish soldering the XLR and look down at the bench... doh!!

You think I'd have learnt by now, but there'es at least one in every batch of mic leads I do.

Justin.

I figure it's no longer necessary now, but here's a recent arrival at Geofex:

http://www.geofex.com/Article_Folders/how_to_solder.htm

The whole "don't put solder on the tip" thing is a good basic concept, but of course real life is more nuanced. I've found that a bit of solder on the tip ("tinning the tip") helps by acting as a heat-transfer medium between the tip and the joint. Plus there's something good about having some fresh flux on there. With the silver solder I have to tin the tip right before using it, or it takes longer to heat up the joint.

Quite often I'll melt a bit of solder into the connector before putting in the wire. The wire itself is tinned, and then I don't have to try to hold ten things at once - just the wire, because the connector is held in a vise and the solder is already present. Heat up the joint enough to melt the solder, slip the wire in, and then let it cool down. Very quick that way, which reduces the risk of melting the insulation around the connector.

Amen to Scodiddly. Another recommendation: try to have the leads/wires being soldered together already fairly soundly connected mechanically. Solder is a soft material and also not really that good a conductor either. So twist or otherwise anchor your conductors before the soldering.

There is a tradeoff here, as this will make the stuff harder to dissassemble if you change your mind. So if you are just tacking in parts to home in on a value that works best, remember to do a good mechanical connection after this determination.

Another suggestion: have a fan gently running to blow the fumes of the flux and solder away from immediate inhalation. Don't have too much airflow or it will cool the joint you are attempting to make too much. Even better are some filter-fans that are made for this purpose and capture much of the vapors.

For years I worked without this sort of thing and still do from time to time---at least I follow the practice of our ex-President and don't inhale. At one point a friend with access to a mass spectrometer asked for a sample of the solder I used, and came back quite excited: the lead in it had an isotopic constituency that made it readily identifiable as from lead mines in Australia. Thereafter he got a blood sample and was able to tell me what portion of lead in my blood was from the solder inhalation and other ingestion.

The result was that about one-quarter was from the solder. The remainder was due to living in LA during the years when gasoline still had lead additives.

[quote author="bcarso"]The result was that about one-quarter was from the solder. The remainder was due to living in LA during the years when gasoline still had lead additives.[/quote]

:shock:

My order from Mouser should show up tomorrow, and includes a solder fume filter fan thingy. $105, but I figure I do enough soldering that I should be careful.