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Old 02-17-2010, 05:30 PM   #17 (permalink)
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Originally Posted by williamson View Post
jfitzpat raises important points that we should address. People should get some leadfree solder, and try it for themselves. Maybe someone with lead-free solder, (that they no longer need) could drop about 12 inches in an envelope to any one requesting some. A roll is about $30.00 Secondly, as I think I mentioned, we should never discard a lead-soldered PCB- or any electronics, in any way except approved re-cycling for lead-soldered products. So, if you decide on lead solder, you commit to responsible re-cycling.
When lead poisoning used to be called "plumber's cough" and "plumbism", your 100 years of leaded solder quip seemed clueless. But this new tact is just silly.

1.2 oz of .032" diameter SAC305 solder (with a 'no clean' flux core) is about $4.50 at Radio Shack. Probably less from Digikey. If the handy little plastic dispenser isn't enough, a .25 lb. roll is $12-$14.

Compliance in CA has been since '07, so most of us engineering types here have been using lead free to hand solder surface mount parts for 3.5-4 years. The bottom line? It is all about a more heat and getting used to it. SAC305 (which I'd recommend for the casual electrical connections) melts at ~217C. SN100 (which you'll see in some manufacturing) melts at ~228C. A 63/37 tin/lead alloy melts at ~183C.

As a practical matter it means that you need to a) be more careful about picking solder diameter b) you need to be more careful about keeping your tip clean and properly 'tinned' and c) you want to be careful about mixing and matching.

That is, 'this tub of flux I've always used' may not be high temp and may turn black at the higher temps involved. Also, the alloys don't flow well on each other. That part is of note because lead free parts, which are becoming the norm, are harder to solder reliably with leaded solder than with the lead free alloys they are designed for.

We could pretend that we are planning an arctic expedition by dogsled, or face the reality that one of the largest densities of electrical hand solders in the country went through this, largely without pain, years ago. Clean and re-tin your tip (or, if you are lazy, buy a new tip), practice a few joints, and get on with your life.


Last edited by jfitzpat; 02-17-2010 at 05:32 PM.. Reason: Topo
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