silver solder

N

nedmin

Well-Known Member
Joined
12 Oct 2002
Messages
1,504
Location
north lincs.
Visit site
for all you handy lads out there. Have you tried silver solder?just repaired a bracket out of mild steel using my propane gun, very strong job. bit expensive to buy about £3 a rod but enables brass,steel and stainless to be brazed without welding gear or oxygen.Made a boarding ladder out of 1inch square tubing, butt welded the steps and very strong.
 
I suppose that....

..you are talking TIG vs. silver soldering?

Well, this is a bone of contention in the bicycle world and has been for a long time. traditional British bikes were joined with lugs, which provide the strength of the joint, held in place with silver soldered jointing. whereas modern mass produced bikes are butt welded using TIG or MIG technology. However, NOBODY advocates butt joints held together by "hard" soldering.

The other drawbacks in the marine SS world are discolouration and corrosion in the finished and polished joint over time - bikes get painted afterwards and the effect of oxidisation related discolouration in the brazing process itself which is prevented with TIG by the inert gas "cloaking"

Steve Cronin
 
Yes. There is a range of alloys available with different melting points to suit different purposes. At one time they contained cadmium which gives very toxic fumes but I think all the modern ones are Cd free. Just check to be sure though.
 
[ QUOTE ]
Also stronger than welding (for some peculiar molecular reason that is beyond my comprehension).

[/ QUOTE ]Pardon!

I think you are a little confused - a properly made weld is stronger than the base material. I think you are referring to the fact that silver soldered or brazed / bronze welded joints can exhibit tensile strengths much greater than the silver solder of brass / bronze filler material but NOT stronger than a welded joint.

If you have developed a process wherby silver soldering is stronger than welding I suggest you patent it quick then sell it to the metal joining industry and retire.
--------------------
hammer.thumb.gif
"Artificial intelligence is no match for natural stupidity"
 
To answer your original question, the answer is yes.

When I was rebuilding our Volvo diesel I found a faracture in a join in a part of the 'excess fuel' takeoff pipe assembly which couples all the injectors together and puts excess fuel back in the tank. I silver soldered the previously brazed joint back together, painted it with volvo green paint and saved a load of money.

Using the right flux and a good blowtorch silver soldering is not difficult.
 
Re: welding vs solder

Cliff,

I spend most of my life as a stress engineer. I've played with aeroplanes at times, where much is glued together. With good/excellent joint design even something as weak as epoxy can give a joint strength in excess of that of a welded joint - or the parent metal even. Soldering is glueing with metal.

However, and it is a big 'however', with poor or even mediocre joint design the joint strength cannot possibly be remotely near welded strengths.

I wish everything was black & white.

Regards,

Richard.
 
Re: welding vs solder

Richard,

I have spent my working life as a metallurgist specialising in welding engineering and metal joining with a wee bit of corrosion engineering thrown in for fun.

In any metallic material with the exception of Copper or Aluminium and their alloys, a weld is superior to a brazed or soldered joint. If one can afford to use lap joints (think of Yorkshire capillary plumbing fittings) or fine angle scarf joints then one can under proper conditions produce a brazed or soldered joint stronger than the base metal. To produce a butt joint welding is the strongest method. Joint design is the main determining factor in most cases followed by produstion constraints and service.
--------------------
hammer.thumb.gif
"Artificial intelligence is no match for natural stupidity"
 
Re: I suppose that....

Bl---y hell, I only mentioned brazing,still its all interesting stuff, thats one thing about the forum we learn all the time. Regarding toxic fumes I wondered why I was sat on the apex of the roof just after I,d finished the job.!!!
 
Re: I suppose that....

I was at a WD and camping show on the weekend, and a chap was demonstrating "soldering" aluminium with an LPG blow torch, and a "rod" of something (Al?). He was using Al softdrink cans to demonstrate. It seemed to work well.

Ray
 
Re: I suppose that....

Cliff, my metallurgical knowledge is limited but wouldn't it be fairer to say that the metal in the heat affected zone of a weld is WEAKER than the weld itself rather than saying the weld is STRONGER than the parent metal?
 
Re: I suppose that....

No. that is unless one has completely messed up the process.

During mechanical testing of procedures the parent matal is normally the part that fails not the HAZ or the weld metal. If the failure occurs in the haz or weld metal the procedure fails unless the uts is higher than the specified minimum for the base material in which case the procedure may be accepted.
--------------------
hammer.thumb.gif
"Artificial intelligence is no match for natural stupidity"
 
Welding etc.

On all the weld testing I've done (aluminium [6082, 6063, 6005] and steel [S275/ S355]) it's always the Haz that gives up first if the weld gives full penetration. That could be a reflection on the company's DNV approved welders though. My own welding (unfortunately) is of the swiss cheese variety - soft & full of holes.

Lap joints & butt joints.. Yep, that's what I was meaning about good joint design.

Regards

Richard.
 
Re: Welding etc.

Interesting. I have to say that's been my experience too! Assuming fairly ordinary steels and compatible filler rods / wire they always seem to go round the edges of the weld!
 
Re: Welding etc.

Guess we work in different industries with different acceptance criteria.

You could always age harden your aluminium welds prior to testing.
--------------------
hammer.thumb.gif
"Artificial intelligence is no match for natural stupidity"
 
You must log in or register to reply here.

Share this page

Top