Soldering Flux

[brightonBreezy]

Hi folks,

If you're on several modelling fora you will probably see this post several times - apologies! And I hope I've posted in the correct topic!

I'm looking to canvas views (and advice) on soldering flux as there seem to be a lot of conflicting opinions and 'facts' (not sure whether the quotes are justified).

There are several types of soldering that I want to do: electronics, track (on PCB), brass kits, white metal kits and, occasionally, track on plastic sleepers (e.g. turnouts).

So far, it seems that for electronics, simple multi-core solder is fine, but liquid flux won't hurt (so long as it's not acid?).

For all the other jobs I've had advice that I should only use liquid flux, that I can use multi-core, that I can use both, that acid flux will attack a joint unless washed and that rosin flux (as in most multi-core) can leave a film which doesn't take paint very well.

Any advice gratefully received!

Pete

[Dad-1]

I don't do brass kits and any white metal I've used superglue.
Most soldering done using multi-core, except track on to
copper-clad sleepers where I use a liquid, Carrs Red.

I do have a tube of paste flux that has been used very occasionally.

I certainly don't see myself as a soldering guru - A bodge job man !!

Geoff T.

[centenary]

In respect of soldering wiring, flux will certainly make it easier but you dont need to use it. If you have no flux, you can use vaseline as a substitute and yes, it does work!

Electrician's multi core solder is adequate, they use it a lot but can leave an orangey residue that should be cleaned away. Cant speak about soldering kits or anything else as I dont do that.

[TomTom]

This is one of those topics that you are going to get as many options as replies, but after decades of soldering, I use the usual multicore for all electrical work and a 145 degree plus La Co plumbers flux- after trying many others - for brass, with complete success. If you can get hold of 100 degree solder for whitemetal, along with LaCo flux, it is far easier than the traditional 70o stuff as it has lead in it and it flows far easier. This changed making white metal kits from a battle to being almost like using poly for a plastic kit. To solder well, everything must be clean, with any oxidation removed, a good soldering iron - most of my work is done with a 25 watt one, and keeping the tip clean. I use a brass swarf cleaner between every application and this makes for a good job and a long lived tip.

HTH

[End2end]

So far, it seems that for electronics, simple multi-core solder is fine, but liquid flux won't hurt (so long as it's not acid?).

For what it's worth, I've soldered half the editing suites in Soho. I never used flux. Only multicore solder.
Can't say anything about brass kits. I've never built one.
Lead free solder is crap despite what the namby pamby brigade want you using.
Thanks
End2end

[mattmay05]

As I build kits, and have a topic on it here on the kit build section.

Flux with acid is used for Brass and white metal.
Solder for Bass 188 degree for strong joins and 145 for smaller detail parts.
Iron wise I use a 30 Watt iron for brass.

White metal you will probably require a different iron 15-25watt as the melting point of the solder and white metal is extremely low.

For PCBs or electrics, multicore solder most have some sort of flux in them to help.. not that I've noticed, you can get flux with no acid to help with the flow.

[Bigmet]

...There are several types of soldering that I want to do: electronics, track (on PCB), brass kits, white metal kits and, occasionally, track on plastic sleepers (e.g. turnouts).

So far, it seems that for electronics, simple multi-core solder is fine...

Because my late Pa was an electronics engineer I was soldering by the time I was seven years, always with 'Ersin' multicore solder. But I have done all the above with multicore solder! No one to tell me there were alternatives until informed otherwise by a member of a local MRC!

I still have a couple of whitemetal loco kits and quite a number of wagons assembled this way. Looking at them now, I am somewhat puzzled how I managed to do it without causing any damage to the thinner sections such as brake gear... (I do it properly now with 'low-melt' solder.)