Solder differences and desoldering tools/technique

[eccerr0r]

Re: Solder differences and desoldering tools/technique

Speaking of solder, I have some noname 99.3/0.7 (Sn/Cu) lead-free solder. It is supposedly "rosin core" flux but when I cut a piece of the solder wire off, the "core" looks white-ish.

Recently I got a small tub of pipe solder flux, and this stuff is white (!!!).

This is 0.4mm wire solder so it's definitely not for pipes. Anyone know what kind of in-wire flux this is? I sure hope it's not the white acidic flux.

Incidentally, when heated and vaporized, this stuff does smell like rosin. Just looks too light colored to be rosin...?

[stj]

Re: Solder differences and desoldering tools/technique

leadfree solder cant use pure rosin, the big delay developing lead-free solder was the time taken to get the flux right.

[eccerr0r]

Re: Solder differences and desoldering tools/technique

Ah, interesting. That would explain things, the flux core must be some mixture of rosin and something else or something else entirely.

I wonder if this roll of 99.3/0.7 will start growing whiskers. and oops, this is actually 1mm solder, not 0.4mm, but in either case it's not pipe solder which tends to be quite thick...

[stj]

Re: Solder differences and desoldering tools/technique

i think the wiskers thing is mostly myth.
to get something to crystalise it has to come from somewhere - maybe poor cleaning at a pcb factory leaving a very thin layer of tin-plating solution on the board.

i'v seen no evidence online on anything hand-soldered.

for serious work, there are even special solders from company's like Fuji with stuff like Bismuth added - but that shit costs a fortune!

[clearchris]

Re: Solder differences and desoldering tools/technique

To replace caps on motherboards I often use a hot air SMD station (preheat), soldering iron and desoldering gun. On stubborn caps sometimes I heat each lead and gently rock the cap back and forth until it comes out.

A few years back I bought a Aoyue 474A++ and I'd never want to go back to a solder sucker. It's really quite a luxury that makes repairs so much quicker.

[mattch]

Re: Solder differences and desoldering tools/technique

I found some SS dental picks I use to Poke hole through solder pad, no heating required!

[Curious.George]

Re: Solder differences and desoldering tools/technique

To replace caps on motherboards I often use a hot air SMD station (preheat), soldering iron and desoldering gun. On stubborn caps sometimes I heat each lead and gently rock the cap back and forth until it comes out.

On stubborn <whatever>, I physically destroy the component to leave just the "pins"/leads in (or on!) the board and then remove the remains, individually. Particularly useful when removing from solder (foil) pours that haven't been sufficiently thermal-relieved!