[Zorander]

Hi all,

I'd like to practise making DIY cables, but I'm lacking virtually any theoretical and practical skills on soldering. I've read a bit on the techniques of soldering (in short, clean surface, heat solder tip & core/conductor, let solder come in contact with hot conductor surface so it flows nicely, let cool; obvious things to avoid: excessive solder, overheating, no eye protection, no ventilation). However, I know for sure things in reality don't work out so easily. I'm going to do some test cables tomorrow but I will greatly appreciate any soldering tips you experts can give me. Thanks!

 

[mono]

Practice on scrap materials. Nothing beats honing the technique before risking expensive parts.

Clean the iron tip regularly and tin it before use. Some connectors 'sink a lot of heat, underheating can be a problem too. If in doubt or on hard to solder surfaces, use supplimentary flux. Flux is addictive, when you see how much easier it can make some jobs you will even use it when you don't need it.

 

[AndrewFischer]

I've got a few.

Tools and supplies:


For now don't spend a fortune on high end solder. Multicore and Kester are good brands. Get a small diameter solder.
Eutectic solder is slightly easier to work with. I use non-eutectic 60/40 tin/lead Multicore in 0.61mm for about 90% of what I do.

A good soldering iron makes a big difference. I have a Hakko 936 at work and two Weller WTCPTs at home. Both are good. I prefer the Weller. Others prefer Hakko. Used WTCPT irons are on eBay all the time.

You need a wet sponge to clean the soldering iron tip. In a pinch I've used wet papper towels. A sponge works a much better.

Avoid Radio Shack


Technique

Be sure to tin and clean iron tip right before you start. Melt a small amount of solder on the iron tip. Let the flux cook for a few seconds, then wipe the tip clean on your sponge. Entire tip should be clean and shiney.


Don't take too long heating up the connection.

As soon as the solder has flowed, take away the heat. Don't overcook your connection.

If you are using non-eutectic 60/40 solder, be sure the joint doesn't move untill the solder has cooled some.


Practice on wires or other cheap parts first.

Try not to burn yourself. Try not to burn the iron's power cord. Put the iron in a stand when you aren't using it. I know this is obvious, but I've seen many beginners not pay attention to where the iron is.

Wash your hands when done.

 

[jl123]

Take a look at this

http://radiojove.gsfc.nasa.gov/elab/soldering.htm

 

[AndrewFischer]

Good videos.

If you look, he does what most of us do and the books say not to. Touch the solder to the iron tip initially to get a little molten solder flowing onto the joint. This works well. If you do it wrong you end up with a cold joint.



The example board has a lot of solder on the connections. Way more than I use and it looks a little messy. There are a few places where the flux was bridging between traces. Hard to tell, but I think someone scraped it away. Too much solder.

 

[Zorander]

Thanks for the videos. That says more than a thousand words.

BTW, I noticed he simply shaked away the excess solder off the tip (when cleaning it). Is that a recommended practice?

 

[MacTheCat]

Hmm. That does seem a bit unsafe. It is probably just as easy to wipe it off onto a sponge. Personally, I don't want to flick off blobs of molten metal. For my sake and for the sake of what ever I am working on.

 

[Zorander]

Quote:

Originally Posted by MacTheCat Hmm. That does seem a bit unsafe. It is probably just as easy to wipe it off onto a sponge. Personally, I don't want to flick off blobs of molten metal. For my sake and for the sake of what ever I am working on.

Yeah...I was taken aback when I saw that part. And he was supposed to be teaching newbies on the practises of soldering. Maybe he was doing it in an already filthy workshop so that's why he did not care much.

 

[AndrewFischer]

Quote:

Originally Posted by Zorander Thanks for the videos. That says more than a thousand words. BTW, I noticed he simply shaked away the excess solder off the tip (when cleaning it). Is that a recommended practice?

I don't do that because it is messy.

The temprature sensor in the Hakko 936 is somewhat fragile.
Hakko specifically says not to tap the iron against the work bench to shake off solder.
http://www.hakkousa.com/techDoc/Manuals/936e199809a.pdf

The Weller WTCPT uses a ferromagnetic temprature sensor that is more rugged. One of the things I like about the Weller.

 

[mono]

Re: shaking off solder - depends a lot on the environment, workstation. I'd be a lot more likely to shake off solder in the garage or basement than elsewhere in a home environment.

I'm bound to start a controversy with this but I don't think the iron matters much. I mean brand or quality. I can solder very delicate parts fine with just about any iron including the $5 Radio Shack special or the generic $3 irons found on the 'net. Mainly the problem with them is slower temp recovery time, limited selection of temp (no adjustment), and the tips are ate up by the solder pretty quick, the plating comes off and they need touched up before every use. These are all bad things, but generally, until you get into surface-mount parts the difference isn't revealed, the basic circuits we're building are pretty easy if you remember the basics like keeping the tip clean and tinned. I seldom run upstairs from the basement to get a better iron and am none the worse for it.

I'm not suggesting someone should make due with the junky Radio Shack iron for a lot of work but to build one project like a CMOY, it will do fine. Technique matters most. Move up to a good iron when you feel the work warrants it, same as with other better quality tools. I only mention this because it's easy to recommend good quality pliers, crimps, strippers, iron, etc, etc... a few hundred dollars worth of tools ideologically for someone just building a few cables and a Pimeta and in that case the return on the tools is low. If you're constantly using them it's a different story so there are at least two distinctly different classes of builders here at Head-Fi.

 

[Teerawit]

Quote:

Originally Posted by Zorander BTW, I noticed he simply shaked away the excess solder off the tip (when cleaning it). Is that a recommended practice?

It doesn't matter much. The solder will solidify very quickly and won't stick to your workspace. Just don't shake it onto yourself

otherwise the solder shouldn't bounce back at you.

 

[cire]

Quote:

Originally Posted by mono I'm bound to start a controversy with this but I don't think the iron matters much.

when you're new, you're more frustrated by lack of technique, than a cheap iron, but as you get better, a point comes where you can start blaming that piece of crap and not your skill. it took me a fair amount of time to get to that point after using the cheap weller iron my father used when he was in college. at that point, i was incredibly frustrated and was about to buy the circuit specialist clone, when my dad came home with a weller WES51. the difference is just phenominal....

does anyone actually use eye protection when soldering? i know i don't, and i've never heard of anyone who did.

 

[Zorander]

I got myself a RadioShack-equivalent soldering iron (as a beginner's tool). This thing does not have any switch nor temperature control. A flick on the mains switch and the thing is running. Any tips on how to use this kind of iron? Thanks!

 

[AndrewFischer]

Quote:

Originally Posted by Zorander Any tips on how to use this kind of iron?

For the most part use it just like any other soldering iron.

After the iron has been on for awhile, the handle may get very hot. Not much you can do about that. Just expect it.

A temp controlled solder station has about 50W of heat that cycles on and off to keep the tip at the set temprature. A low-cost RS type iron has about 20W of heat that is always on. After sitting for a minute or two, the tip can get over 500C. You have to be more carefull not to burn your work. This is critical with smaller connectors. You may have to keep your dwell time (time the iron is on the work) down to 2 seconds or less.

With a large connector, a 20W heater will take longer to get the connection hot enough to flow the solder. You may have to keep the iron on the connection longer.

Just like in the video, after the solder flows keep the iron on the connection just a second longer then pull it away. If the solder isn't shiny, you didn't have enough heat. If the flux is black or the wire insulation is burned, you had too much heat.

Trial and error learning is best.


If you are only making a few cables and you aren't spending more than $50US on parts, I don't see a reason to get a better iron.

If you are spending $100s on high end parts get better tools. Its worth it.

 

[saab]

Quote:

Originally Posted by cire .... does anyone actually use eye protection when soldering? i know i don't, and i've never heard of anyone who did.

Pretty much always, but in the form of glasses. I usually take out my contact(s) before I go downstairs to solder. This gives me some protection, and I can see better up close when I am not wearing contact(s).