Topic: Quick solder question...

Hey chaps

I'm looking at making up some stainless steel pushrod linkages and need to do some soldering on them. Am I right in thinking that I need to use a flux which has acidity to it and also probably some silver present in the solder alloy? Any other barriers to a good joint?

Thanks

Z

 yes you need some "special " flux for soft soldering ST ST . Mine was mixed by the rocket lab at work in 1964  so I guard it with my life , I have never found anything close , The guy passed away with the secret !

I find silversoldering these items easier and better .

pop over for some

stig

He he Stiggy - man in a shed has all the answers amongst his shelves full of alchemy!

I'll pop over sometime mate and show you what I'm up to with it... Gotta buy some parts first...

Cheers

Z

 you know your always welcome !

see ya

stig

Dont suppose your mystery chemist was knocking up some killed spirits do you?.....back in my appretice days in the tin bashers shop we used to knock up a bottle each which would then be used for the rest of your engineering apprenticeship whenever the need arose to solder something.

If I remember correctly we used zinc and hydrochloric acid which used to bubble away and give off some powerfull fumes...this zinc would bubble away in the acid whilst we all nipped outside for a fag.

Can you imagine doing it today with the elf and safety brigade just imagine 10 x 16 year old apprentices all brewing hydorchloric acid and zinc with hydrogen gas bubbling away under your noses..then heaven forbid being encouraged to go out for a smoke break...

It made fantastic flux and you could solder anything with it providing it could be washed off afterwards.

Z

The flux for soldering stainless is phosphoric acid.

http://www.mistralni.co.uk/products.php?type=acid

Bert

Do you just dip the part to be soldered Bert? 10% conc?

Z

 as I said before my alchemist friend  passed away many years ago ,not of any related reason !! and before I retired  I realised  my "stock " was going to disappear  so I put some thro the spectrum analyser to see what it was .

The results were totally inconclusive in as much it had many ingredients  that the present lab men could not assemble into  a "flux "

It was obviously used at/for work as all the rocket components were st st pickled and passivated .

the way I use it is to dip the solder into it then place the solder on the component(s) to be soldered , yes it smokes , the fumes are pretty awful , probably deadly and yes you wash the components where possible .
I use st st straps when I build up battery packs , cos my spot welder machine was sett up with st st in mind , so I need to "tin " the ends .

so yes it appears to be nasty stuff

stig

Do you just dip the part to be soldered Bert? 10% conc?

Z

Yes, or dip the solder and transfer it to the work like just like the wise old Stig says 

It's what they used to put in rust remover like Jenolit - maybe they still do.

I think it's also in Coca Cola though a bit more dilute!

Bert

Hello ,
Say someone is silver soldering a piano wire of say 1/8" dia.  to two brass horns.  The horns are very close about an inch.  I will be using a propane hand held refillable small torch with the capacity.  Will the heat from second soldering ruin / weaken the first one?  Does one due both of them at the same time?   Would clipping a piece of metal between to sump the heat help?
Take care,
Albert

It might be best to create a jig or clamp to keep all the parts in place. That way there would be no concern if both joints were heated at the same time.

Hello,
Would adding a heat sump help?  Has anyone done this double horn on one wire before?
Thanks,
Albert

Hello,
Would adding a heat sump help?  Has anyone done this double horn on one wire before?

I've certainly used a heat shunt before, there are even proper tools to do it.

The jig is the best idea - it doesn't need to be anything fancy, a couple of clothes pegs screwed to a bit of wood would do it, as long as it holds them in the right place.

Hello,
Thanks guys will proceed with holding with simple jig and maybe doing both nearly at the same time.
Enjoy,
Albert