A bad batch of solder paste cost me a full day on a repair job

I grabbed a new jar of generic solder paste for a quick antenna coax repair last Tuesday. The stuff just would not flow right, it kept beading up and leaving cold joints. I spent about six hours reworking the same connection, checking my iron temp and flux over and over. Turns out the paste was way past its shelf life and had separated. Has anyone else had this happen with off-brand supplies? What's your go-to brand for paste that you trust?

2 comments

2 Comments

kellyr181mo ago

I had a tube of no-name paste sit in my toolbox for maybe two years... used it on a simple USB port and created a bridge so bad it looked like modern art. I stick with MG Chemicals now, their 4860 flux has never let me down. That generic stuff is fine if you use it fast, but it goes bad way quicker than they say. I learned the hard way to check the date code before I even open the jar.

gray_nelson1mo ago

Ever wonder if storing flux in a toolbox is the problem? The temp swings from a hot garage to cold nights might wreck the paste faster than the date code says. @kellyr18, your art project makes me think moisture got in that tube and turned it into conductive glue. A cool, dry cabinet might keep even the generic stuff working longer.