Leaded and lead-free solder don't mix?

[sosidge]

Been having a few problems with solder joints which I have had to re-do with lead-free solder failing (only thing I could get locally).

Is this a known problem? Or is it just me?

[Northy]

IMHO don't use lead free solder unless you are forced to do.
The two will mix, but lead free needs higher temperatures to solder properly.

G

[blue_pinky]

The problem could be a couple of things...leaded solder has a lower melting point than lead free, and the flux in the 2 solder types is probably different as well, so that's probably not helping either.

I'd always suggest a pure joint () is more reliable!!! Do you have a solder sucker or any de-soldering wick to clean the joints up with?

It might be too late, but if you'd like some leaded solder I've still got some and always have it with me at club. I also have a solder sucker, but no wick right now, that can be cheaply picked up off ebay though.

[Big G]

I use silver solder from maplin... could this be a problem?

had a couple of motors unsolder their wires, but I always put that down overgearing...

[blue_pinky]

In theory silver solder should be better in that respect, it has a higher melting point and is better at coping with thermal cycling, but is less ductile, so is more brittle...did they unsolder due to heat or break off due to mechanical load/impact?

Since you've mentioned it, my guess would the overgearing theory you have is probably still right!

[Northy]

Unless you didn't get it hot enough in the first place to get a good joint.

Nothing wrong with standard leaded solder imho.

G

[blue_pinky]

Good point! I'd agree with Northy!

If you google it, the theoretical melting point of solder varies from over 180 Celcius for leaded to over 210 Celcius for typical lead free solders, silver being higher still I'd guess...

...so if your wiring is getting that hot...maybe it could be a bad joint in the first place? Wouldn't it take some sort of electrical fault to get to those sorts of temps?!?!

[Big G]

it's most likely overgearing

my iron is a 12v one that gets so hot I can't even hold it at the middle lol

they unsoldered themself rather than broke off

[sosidge]

Originally Posted by blue_pinky

The problem could be a couple of things...leaded solder has a lower melting point than lead free, and the flux in the 2 solder types is probably different as well, so that's probably not helping either.

I'd always suggest a pure joint () is more reliable!!! Do you have a solder sucker or any de-soldering wick to clean the joints up with?

It might be too late, but if you'd like some leaded solder I've still got some and always have it with me at club. I also have a solder sucker, but no wick right now, that can be cheaply picked up off ebay though.

I got some of Maplin's own-brand-no-brand desoldering wick and it is complete junk! The braid is so tight that nothing will wick up it! I did have some of the Soldamop branded stuff which worked so will have to seek out a small roll of it (Maplin now only sell a giant roll at a silly price).

Maplin is also where I got my lead-free solder.

Maplin is crap.

I might have to get hold of some lead solder again. My understanding is that is is not banned for "hobby" use, even if it is I believe my sponsor still has a few packs hanging around .

[topher2009]

Gents if getting hold of leaded solder is an issue, let me know, i went to a local DIY store the other day and they have a stash of leaded solder on the shelf for sale, I dont mind getting and posting on if needed (I accept no responsibility if you stand over the solder breathing in fumes!)

[ashleyb4]

I use and have always used 60/40 multicore solder lead free. never had a problem with it. But i wouold recomend a big iron!!!!

A

[AlisdairO]

B&Q near me do leaded solder, so I think it's still pretty commonly available.

[damo666]

Deans solder is the only stuff I'll use now after trying and failing with all the other crap stuff.

[Northy]

You do know Deans don't actually make solder....

[Big G]

spotted last night my maplin stuff is actually lead free

Normally no problem doing my soldering, but last night the negative was being a right arse and wouldn't get hot enough to melt. very strange.