Lead-Free Solder

[tommypiper]

OK, I'm buying solder. Lead-free. Is there a difference with copper or no copper in it? I seem to recall someone saying the copper is bad and causes corrosion, is that possible? Would it be bad for gold or silver XLR contacts, for example?

cheers.

 

[SonsOfThunder]

Whoops! Missed this first time around.

Can't tell you much on this subject but we should be discussing this!! I can imagine that this will alter the melting point for certain.

Most of the lead free joints I have seen look rather dull. Not as bad as it was when lead-free was first introduced but not as shiny as we are accustomed.

Here is a blurb from Kester's website touting their super-spiffy formulation...
http://www.kester.com/en-US/products/prodcat_detail.aspx?pid=196#info

According to that, the solder formulations cause corrosion of copper, as in traces. Eeek! I think we in the electronics industry are all in for a tough ride in the next couple of years as we discover all the bad crap that lead-free is gonna sling at our stuff.

HTH! And sorry for the slow response!
Charlie

 

[tommypiper]

Right. So I was correct, there is an issue with it depleting the copper traces. Is that just during the soldering, or over the lifetime of the joint?

I didn't buy solder after my post, since I didn't know what to do.

However, I discovered my old Kester "44" lead solder creates a lot of splatter in some cases, and large pools of flux residue around the joints.

When I made a Scott Dorsey mic mod, he stressed how you need to remove the flux residue to prevent noise in the high impedence circuit. I used off the shelf Ratio Shack lead free solder. It produced shiny, strong joints and very little flux around the joints and no splatter. So it's what I'm using from time to time. However, it needs much higher melting temp, and over time it ate away at the tip of one of my irons. Whao!

Also, someone said the fumes are very toxic, more than lead solder fumes, due to the chemicals in lead free...

Seems we have to choose our poison.

You're right, we should be discussing lead free solder, at least to know which ones are best, and how and when best to use them.

 

[SonsOfThunder]

Well, all solder requires flux for removing the impurities and contaminants on the devices/traces we are soldering together. Rosin flux looks a lot nastier than no-clean or water-soluble formulations but can still cause a lot of problems in high impedance circuits. No-cleans can be really sticky and so you have to watch out for conductive things sticking to it and possibly shorting components. Really, we need to clean that stuff off in any case.

But yeah, finding a good solder that is easy to work/has good wetting properties and doesn't cause us to overheat the components we are putting together, along with having a flux formulation that doesn't require harsh solvents to clean is the ideal.

Or maybe its a good time to stock up on the old leaded stuff til they get this sorted out???

HTH!
Charlie