Lead-free solder

[utopia]

I haven't used this before cos my old stuff has lasted ages, but I had trouble soldering some waterproof connectors with a new batch of solder lately, so I did a bit of research.....

The new stuff is tin/copper, as opposed to tin/lead, and my problems seem to be down to two consequent factors :-
1) lead free solder melting points are around 34deg C higher than tin/lead types. This makes it harder to achieve the required temp, and much more likely that cable insulation etc will be damaged.
2) conventional fluxes don't work very well with tin/copper solders, partly because the increased temp burns them off.

To sum up, lead free solder is sh*te, imho.

[AndyC_772]

You can still get tin/lead solder OK, take a look (for example) at:

http://uk.farnell.com/jsp/search/browse.jsp?N=1003123+359684+359682+359681+359680+3 59679+359678+359677+359676+359708&No=0&getResults=true&appliedparametrics=true&locale=en_UK&catalogId=&prevNValues=1003123&filtersHidden=false&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN% 3D1003123%26No%3D0%26getResults%3Dtrue%26appliedpa rametrics%3Dtrue%26locale%3Den_UK%26catalogId%3D%2 6prevNValues%3D1003123

It's illegal to manufacture electronic products for general sale with it thanks to the RoHS directive (and for vehicles, the ELV directive), though. Lead-free solder is usually almost pure tin, with a few % of other metals added to try and help it flow properly. Unfortunately the alloys which flow properly also require an even higher temperature to melt them in the first place.

You may find that a new soldering iron helps - or at least, a higher setting if you have a thermostatic one. Personally I'm a fan of the Metcal range, and I find one of the 700 deg F tips works well. A hotter tip means the joint heats up more quickly and so you don't need to apply the heat for as long - and paradoxically this means the hotter iron actually causes less damage to insulation and other sensitive items than a cooler one.

Your summary is pretty much the same as mine, and that of the entire electronics industry.

[utopia]

Thanks for that.
I might get a bulk spool of tin/lead stuff for a lifetime supply.....
I had pondered a new iron. My old one is a non-thermostatic 25w mains type, and I was considering a 40w one. I'll check out the ones you recommend. However, my old one has sentimental value cos my mum picked it out of a christmas bran-tub of stockroom oddments from her workplace at the time...in the mid 1970s, so I'm loathe to pension it off.
While I might have the attention of some electrical experts, does anybody know of a decent, cheapish crimping tool that works on AMP Superseal waterproof connector blocks ?

[AndyC_772]

does anybody know of a decent, cheapish crimping tool
Nope... those two attributes are mutually exclusive as far as I know.

This is the iron I have - get yourself a small selection of tips and you're set:

http://cgi.ebay.co.uk/Metcal-Soldering-System-STSS-PS2V-02-/150521262571?pt=UK_BOI_Electrical_Test_Measurement _Equipment_ET&hash=item230bc431eb

[Darkness]

I'm still using some solder sticks that I bought to repair some leaded windows.
50/50 lead tin flows lovely, but the fumes are a bit unpleasant: something to do with them being toxic I think?
Just mustn't use them on water pipe connections or Building Control will throw a right wobbly!!

[AndyC_772]

Rosin flux fumes, most likely. Effective, but it'll eat your lungs.

[johnsy]

Pop down your plumbers merchant, red is lead solder, you can still use it on heating work, it's a lot cheaper than green solder as well.
Theres 2 different fluxes, 1 cleans as soon as you put it on, the other cleans as it heats, again a good plumbers merchant will know the difference and see you get what you need/prefer

I knock monsters with plumbing, yet I'm a plumber, is that an oxymoron or me just being a moron :fou:

[utopia]

I knock monsters with plumbing, yet I'm a plumber, is that an oxymoron or me just being a moron? :fou:

Neither.
It means that, as an expert in the field, you know when plumbing is appropriate, ..... and when it isn't. ;)

[Capo]

I've got an el cheapo crimping tool that I use to crimp superseal terminals, fiddly job, make sure you get the correct size seals if they are too big then they wont seal.

I used to use solid solder wire to balance my wheels

[utopia]

Thanks, Capo.
I was wondering whether the cheapo ones would work if used with care. Though now I've got some proper solder, I've done a decent job soldering the wires and crimping the seals on with thin nose pliers. .....seems to have less chance of cutting the seals perhaps.
I overcame the odd loose seal by shrinkwrapping the ends of any thinner wires to tighten them in the loose seals. I didn't know different seals were available. I'll get some next time.