Soldering thin copper

[daverclasper]

Hi. Picked up an old petrol cap for Vitesse for pennies, that the flatish 3 prong copper thing (looks about 1mm thick), has a split. Looks easy to solder?.

This will anneal/soften it, and I assume a bit of the original horizontal strength would be better?.

After soldering, shall I dunk it in water, or leave alone, or any other ideas please?.

Cheers, Dave

PS. I guess anyway, the copper will be softer than the solder, so may break/split again?, though worth a go me thinks.

Cheers, Dave

 

      

Edited July 20, 2021 by daverclasper

[rlubikey]

The solder used for electronics work (and I think plumbing is the same stuff?) is probably too soft for anything structural like this. I would think silver solder is what's needed here. I don't know the answer to the annealing question, but I imagine someone will be along shortly who does.

Cheers, Richard

[PeteH]

IS it copper?.  I suspect more likely brass, It will still soft solder so long as it is clean and a good flux used, I am old fashioned enough to still use acid flux for such job`s. (non Electrical), Phosphoric acid is often used, but not that easy to get these days. Silver Soldering requires much higher temperature which cannot be acheved with an iron. I use a propane torch, and even an Oxy set.

As for annealing copper, heat to cherry red, imediately plunge into water, sucessfully recovered many a copper washer!.

Pete

[JohnD]

We had a similar conversation here recently, about annealing copper.  I was corrected about slow/rapid cooling, and learnt that copper, unlike steel,  is softer after being quenched, in water.    But I would still say that a washer cools so quickly in air that it will soften well enough.

But here, the copper/brass needs to retain or regain its temper.   So I ask the metallurgists - will a slow cool have that effect?    Will burying it in sand allow it to cool slowly enough?

[RogerH]

Hi Folks,

Copper is odd stuff.

To anneal - heat to cherry red then quench and stir in water - the more rapid the better.  This is unlike Ferrous metals

To harden - not usually done as after it is annealed and then worked upon it will harden (it is called 'Work hardening')

                   Be careful once work hardening has set in the copper may well crack if you try to work it more. Re-anneal if necessary.

Hi Dave  - I can't visualise what you have is it like the pic below  4th line down.  Are you sure it is copper or brass - if so it will solder easily and will no further heat treatment.

               The pic below looks like steel but I'm not sure. If it is steel then this could easily be soldered of silver soldered (a little stronger)

 

https://www.google.com/search?source=univ&tbm=isch&q=Triumph+Vitesse+petrol+cap&sa=X&ved=2ahUKEwjyod2-5fPxAhXaQUEAHQB1AQsQjJkEegQIDBAC&biw=1517&bih=730#imgrc=ig81RlkNyCsvbM

 

Roger

[JohnD]

Which did you mean, Roger?  This one?

     That three pinted catch looks steel to me.

 

Or this one

  Where the  yellow  finish is just anodising, on steel.

 

Dave, show us a pic, please!

John

[daverclasper]

Hi and thankyou all for the response.

Have tried to attach photo's from my phone, though no joy, though I guess it should be simple.

The 3 pronged catch looks the same/very simular to the 3rd photo and was a blackish colour, though when I fine sanded a small section looks to me to be a copper colour, rather than a more yellowee colour I associate with brass. I would have thought though that brass would be more suitable, as a harder metal?.

Cheers, Dave

[RogerH]

Hi Dave,

have you touched it with a magnet to see if it is steel.

 

Roger

[Colin Lindsay]

Dave - is it one of these? (Waso brand?)

 

[daverclasper]

Thanks, will do the magnet test.

No, not a Waso Colin.

By the way, are you ok?. Conspicuous by your absense lately I thought.

[Colin Lindsay]

4 minutes ago, daverclasper said:

Thanks, will do the magnet test.

No, not a Waso Colin.

By the way, are you ok?. Conspicuous by your absense lately I thought.

Elderly mother in hospital, was visiting twice a day... things now improving however hospital has suspended visiting due to Covid so I'm getting a break. Had hardly set foot in the garage in a fortnight.