Solder blobs are not always solder joints ...

[Paul Joppa]

This is just another take on solder joint repair. Something I saw today made me think it was time to say it again.  :^)

Adding solder is not the same as "reflowing" - if the solder joint is bad, it is likely because not ALL the metal involved was heated above the melting point of the solder. Adding solder to the blob does not make the terminal and the wire hotter; usually the iron itself must conduct heat to the terminal and the wires.

The best repair to a bad solder joint is to remove as much of the old solder as possible - you can get a solder-sucker, or use the woven copper tape with flux which wicks it away. Then, when you can see the metal parts, put the iron onto them for a bit before adding solder. Touch the solder to the terminal and/or the wire, not the soldering iron, so you are sure the metal parts are hot enough. When you see it flow onto the parts, then you can take the iron away. One reason this is best it that the flux inside the solder wire will be in the right proportion. The flux that was with the original solder blob has evaporated already, and the excess solder just dilutes the flux in the added solder.

[ramicio]

It's funny to see people who can't solder try to solder.  To a solderer, it seems unimaginable to not be able to do so, and to me, watching an adult do it who can't, just makes them look like a toddler trying to do it.  I thought reflowing was a specific type of soldering for SMD components using paste.

[debk]

Paul

Good post. 

When I repair kits made by others, poor soldering is usually the problem.

Debra

[Doc B.]

It's funny to see people who can't solder try to solder.  To a solderer, it seems unimaginable to not be able to do so, and to me, watching an adult do it who can't, just makes them look like a toddler trying to do it.  I thought reflowing was a specific type of soldering for SMD components using paste.

Reflowing is indeed a method for SMD attachment. It's also what we call reheating any existing solder joint to the liquid state in order to get it to properly distribute itself through the joint, which is of course exactly what is being done with SMD reflow. It's also called rewetting.

If you think watching a person who doesn't know how to solder is funny, you should watch me try to ice skate. I'll bet there was a time when even you didn't know how to solder.

[Grainger49]

I want to note that you need a good mechanical joint first, then cover with solder.  I crimp all my leads onto the terminal strips or tube pins before soldering.  

I get few bad solder joints.  My FP 2 power switch wire fell off after 11 years.  The power switch has no hole in it so it was chewing gummed onto the switch with solder.  It failed.

I should have drilled a hole.  I had the same failure in the Paramount I built, the power switch let go of the wire and solder.

[ramicio]

Roller skating is also hilarious.  I can't do any sort of skating.  I can't handle anything that attaches to my feet and reduces friction from the ground.  If I get a bad joint it's usually because I wasn't patient and moved it before it cooled all the way.

[elcraigo]

I only try to ice skate if I need a broken ankle.
You should see me solder a BGA with those x-ray glasses I got from the back on the comic book.
I almost always burn myself, probably not enough flux.

[Grainger49]

What happened to the wonderful "How To Solder" animation one of the Bottleheads from the old site had somewhere?  That would be great!

[Doc B.]

One day the link was 404. I tried to contact the author, but didn't hear back. We seem to be getting a lot of reasons to acquire a decent video recorder these days. I will look into it when we get a breather - things are really hopping these days.

[InfernoSTi]

What I love about this forum is that folks who don't know how are welcomed, encouraged, and taught.  The "bad" soldering is a lot better soldering than "not" soldering.  With time, the technique improves.  A video and some practice is very helpful.  As are a nice set of forceps for wrapping/crimping....

John

[tmiddle]

Hello,

My first post here, but I've been reading and learning from the forum for several months. I have the Crack kit and tools ready and will soon attempt my first build. I also picked up a couple of small cheap kits that I will use to practice soldering. I would like to ask if most of you here "tin" your wire leads before attaching and soldering?

thanks,
Thom

[Grainger49]

I don't tin but instead put a little solder on the tip of the iron to help the heat spread.  I add solder after the small amount on the pen's tip starts to flow onto the terminal and wire.

[Tickwomp]

I don't normally tin wires before terminating to a terminal unless they are really big or there a specific reason for doing so.  For most terminations, I try to get a really good mechanical connection and then use a tiny bit of solder paste (even with rosin core solder).  I clean up the excess solder past with rubbing achohol and a soft brush. 

A strong mechanical connection will bite you later though if you need to remove it.  With practive and experience you can create a nice tight connect without wrapping the wire completely around the terminal:-) 

Even on some busy terminal positions like 28, if you take your time and are careful can even make that position look pretty good.  IMO, solder flux/past helps prevent blobs by making the solver flow much better.  And with a good mechnical connection, it doesn't take much solder to secure/finish the job.