Soldering

Rosin core for electrical. Acid core is used for plumbing. Lead or lead-free will work. Lead-free has a slightly higher melting temperature.
 
Most common (Radio Shack or what's left of it) would be the "environmentally safe" solder such as is used for plumbing - but with the rosin core.

It works. I've used it. Not well. Not the most forgiving of solder or freely coating. You have to have everything PERFECT: clean copper, right temperature, even wipe the fingerprints off the solder as you use it.

BETTER by a considerable margin is 60-40 rosin core solder - the old fashioned kind. It melts lower, is more forgiving of defects of application, coats your soldering iron better, and is generally easier to use.

That said - lead/antimony solder will corrode in time. One of the defects of 1980s era calculators is that they were done with "dipped" technique using lead/antimony solder. Many of these calculators are now unusable because the solder connections have corroded and the connections don't work (or are physically "sensitive.")

I miss my Texas Instruments SR50 calculator - the one with "Hyperbolic Arc-Sin" (the function that has no practical application in real life - but the calculator will tell you what the value is.)

A solder joint is easy to renew in wiring work - not so easy for calculators.

I have a roll (1 lb) of old fashioned "electronic grade" rosin core solder which I bought on Ebay for mid $20 - it can be found - at a price. This is my soldering "go-to" when it absolutely must be soldered correctly the first try - with no re-tries allowed. I can't think of a joint I have been disappointed with using this solder.

The smell of using this even brings back memories of my Ham Radio experiences back in the vacuum tube age. Yunno - when you could find a power transformer in an old TV at the dump - and build a radio transmitter using it?

Good luck. Several grades below Rocket Science this one. Although this may not be exactly true. Apollo 11 went to the moon on hand soldered connections.

Joe in NH
 
Last edited:
.030" 60/40 rosin core is what I used for all the switch and component soldering I do but the tin/copper will eventually replace all of the lead content stuff. My wife works for a company that assembles boards in and SMT machine then solders the boards with a solder wave machine. They have been using lead free for quite a while. They coat the different boards using several methods and different forms of resin to keep corrosion at bay. The boards wouldn't last long if they did't coat them.

I always tin a wire with solder before I solder it to a component. This way you know it is clean enough to get a good stick. If you can't tin it then it's too dirty and needs cleaning. I only solder stuff when there is no other way. A soldered joint will work harden at the joint and the wire will eventually break if there is vibration or movement going on. I use crimps for as much as I can but they aren't like the ones you buy at the auto parts store and some are pretty expensive.
 
Any electrical solder that has lead works best for me. Get something a bit bigger in diameter. The little stuff is difficult to work with in auto wiring. Make sure the connections are clean and bright. ALWAYS use flux. The old stuff that requires cleanup works, but the modern no-clean paste is really easy to use. Buy a good iron with adjustable temps. I do repairs on modern surface mount circuit boards under a microscope and the flux and lead solder have always worked for me.
 
Soldering can be an art if you're so inclined. The key to soldering is to heat the surface you are soldering and let the solder flow onto, into, and around. Then look at it carefully and pull and poke to make sure you don't have what can be referred to as a cold solder joint. It isn't all that hard.
 
JKY said:
Any electrical solder that has lead works best for me. Get something a bit bigger in diameter. The little stuff is difficult to work with in auto wiring. Make sure the connections are clean and bright. ALWAYS use flux. The old stuff that requires cleanup works, but the modern no-clean paste is really easy to use. Buy a good iron with adjustable temps. I do repairs on modern surface mount circuit boards under a microscope and the flux and lead solder have always worked for me.
Click to expand...

Chrs1961 says no lead and this poster says any solder that has lead! Very confusing. Which is right or wrong!
 
I'll agree with almost everything said, but I always prefer the thin stuff takes less heat to melt it.
I was an AV tech for some time and worked on with circuitry for some time after that as well. Both only ever used Kester Rosin Core Solder. The radio shack stuff is useless in my opinion
 
McMimmcs said:
Chrs1961 says no lead and this poster says any solder that has lead! Very confusing. Which is right or wrong!
Click to expand...

Non lead solder is now the industry standard. It requires more heat to get it to flow properly. Non leaded solder is "safer" to use, but for small, infrequent soldering jobs with ventilation it's not an issue.

I recommend lead based solder because it's easier to get good results. I imagine most people here are not experienced at soldering so the lead based will give them the best results without a lot of experience.

A couple of keys to success:
Use electrical solder
Have very clean surfaces to solder on
Use a good flux (I like the new no clean gels in a tube)
Apply heat to the part, not the solder
Inspect for good joint and watch for cold solder joints

Hope that helps!
 
63/37 solder is less prone to cold solder joints. When I worked for Motorola use of 60/40 voided the warranty. When soldering wires, make sure the solder wicks back into the wire, underneath the insulation. Also, use a big enough iron so you can heat the joint quickly, get the job done, and let it cool. Too small of an iron will actually end up with more heat damage. Use a brass brush on the soldering iron tip to keep the tip tinned with new solder. after a while the solder on the iron can become dead and that will lead to a poor connection. https://www.ebay.com/itm/63-37-Tin-...555074?hash=item1e9702b1c2:g:xn8AAOSwi5VdyNhH
 
Last edited:
You must log in or register to reply here.
Back
Top