non-authentic solder?

[user_x]

Beginner question: I recently bought some no-brand solder from https://www.walmart.com/ip/WALFRONT-50G-0-2mm-0-6mm-60-40-Rosin-Core-Flux-1-2-Tin-Lead-Roll-Soldering-Solder-Wire-Solder-Wire/851462676, which is supposed to be to be 60/40. However, I had a lot of headaches with it. Just tested today that it starts to melt at 230 deg C! Perhaps this is lead-free solder? Any recommendations for where to buy authentic solder instead? Thank you!

[wraper]

How do you measure that temperature? If it's simply soldering iron setting, then sounds about right for leaded solder. Lead-free solder is more expensive BTW. Unlikely that someone will substitute leaded solder with lead-free.

Core Flux 1.2%

Probably this is your problem.

[WattsThat]

In the US, Kester is the big brand and the big distributors are Digi-key and Mouser. They are easy to deal with but not always the cheapest. Plenty of choices there. I use a local supplier with free will-call pick up. http://www.techni-tool.com/

Once you’ve settled on a brand and type, you can google it for the best deal. Amazon of course has everything. I’ve used goKimco as well with good service.

[TimFox]

Easy mnemonic:  50-50 Sn-Pb solder melts at 212 C (not F) liquidus, and 60-40 melts at a lower temperature.  The 63-37 binary eutectic melts at a single temperature of 183 C.

[user_x]

Thanks! I checked the melting temperature with my new hakko 888-D, and 230 C is the displayed temperature (factory settings). Thank you for pointing out the core flux problem! I also thought that lead-free solder would probably be more expensive...

[wraper]

Thanks! I checked the melting temperature with my new hakko 888-D, and 230 C is the displayed temperature (factory settings).probably be more expensive...

You need a significantly higher soldering iron temperature than solder melting point to actually melt solder wire. If you cut a tiny piece of it and place on well tinned tip, then you may get it closer. You need to account for solder wire sinking the heat away from the other end, not to say air transferring the hat away all around.

Thank you for pointing out the core flux problem!

1.2% is a very low amount of flux. Normally you get 2-3 times higher flux content. With such low amount of flux you need good surfaces and tightly controlled process for this amount to be enough to do the job and not to burn out prematurely.

[user_x]

Thank you! Yeah, I melted the solder first and turned down the temperature slowly, waiting for it to freeze (consolidate?). So I guess that might be reasonably close

[radiolistener]

I'm using 1 mm 60/40 solder wire at 280-290 °C. Works ok.

When I need to solder big metal polygons, I setup 300-320 °C.

Just tested at 220 °C. At a glance it can melt solder, but from my point of view this is too small themperature for soldering.

[bdunham7]

Basic:

https://gokimco.com/collections/solder-flux-paste-wire/products/kester-24-6337-0027-sn63-pb37-solder-wire-44-rosin-031-diameter-66-core-1-lb

Silver:

https://www.concorde-electronics.com/products/kester-24-7150-0018.html

You should at least try the first one.  A 1 pound roll may last you a very long time, but if you do use it up and want to try something else, you'll have a reference to compare to.  Soldering get a lot easier when you skip the crap products and tools.  And, b/t/w, I use 350C as my temp setting and I move fast.