silver soldering

[compound driver 2]

Hi
Citric in the Uk is about 75p for 100 grams and thats enough for 1/4 gallon of water. When I use citric i mix two gallons water with 400-500 grams of citric powder. Most chemists will get it for you or stock it in 100 gram bags.
Its worth pointing out I do this for a living so stronger acids are a big advantage time wise. If its for a hobby then take the safe rout and dilute further.

Cheers Kevin

 

[Loose nut]

Hi


Battery acid at 3% would work but in all honesty would take as long as citric acid to work. Sulphuric can be had reasonably easily in the UK and the US.

Cheers Kevin

The acid I use at 3% will clean copper or brass for soldering in about 5 minutes, a little more if it is really dirty and leaves a matt finish, so it might not be any good if you want a polished look when your done. Citric acid is available in most grocery stores in North America, it's used for canning some types of food, another mixture is ordinary vinegar (acetic acid) mixed with salt but I don't remember the ratio, it works about the same as pure citric acid mix. In Britain there was a company selling "Four H's" (not sure of the spelling) pickling for model engineers, suppose to be safe, they advertised in Model Engineer magazine and they may still be around. Sulphiric acid is dangerous to children, animals and idiots so if you are going to use it, do so safely.

 

[rickharris]

Citric acid is available in every supermarket in the UK as Kettle descaler - Check the Ingredients on the packet.

I use it as an acid pickle for jewellery - it works quite quickly (relative to safety pickle) and smells nice.

the druggies use it to manufacture crack Cocaine I believe. I guess they could always squeeze a lot of lemons.

 

[compound driver 2]

hi
My only issue with citric is the time it takes to remove flux from a joint. I always worry that it leaves flux inside the boiler at the end of the build. For that reason I always pickle in sulphuric. Having said that I do use citric acid on some jobs and its handy to just drop a boiler in the citric at the end of the day.

We all have to be happy with what we use to do these jobs be it work or hobby. Personaly I have no problem using strong acids, I am aware of the safety issues and I also am aware of the safety equipment that I need to use.

Most small silver soldering jobs will work fine with nothing more than a polish of the bits with scotch brite, but some jobs have to have a degree of cleaning way past this.


Cheers kevin

 

[Bogstandard]

Kevin,
Don't get me wrong, I used to use sulphuric, but the safety issues when the grandkids came along, forced me into using a safer method.

What I personally was worried about, was someone with very little knowledge of its handling. Emptying an old battery, using it, then someone having a serious accident.

As you mentioned, there is a great difference between amateur and professional workshops.

In the restricted, kiddie and animal runaround areas we tend to use, the safest solution is the best, even though maybe not the most efficient.

John

 

[compound driver 2]

Hi John
I fully agree.

My pickeling tanks are locked up at the end of the day as are the fresh acids.
One of the other poinst is keeping chemicals seperated from each other, thats sometjing not many give thought too in the amatuer workshop.

Im all for safety in every walk of life.

Cheers kevin

 

[firebird]

Hi

I managed to fix the wifes necklace. I found some old cheap and nasty silver jewellry to practice on and very quickly discovered that the propane torch I have even with the smallest jet fitted was far to big. I found that with a No. 1 jet in the oxy/acet gear I could get a really small flame. Holding the necklace in one of those little helping hand things with the magnifying glass I put some flux on (spit mix) wrapped a tiny amount of very fine silver solder round the joint to be repaired and brought the torch slowly in. In seconds the solder melted and fixed the broken joint. Today at least I am her good books and can spend the rest of the afternoon playing. On the subject of citric acid I bought mine from Wilkinsons. Its in the home brew section.

My daughter has just handed me a piece of paper with instructions for making a solution to clean old coins. She got it off a TV prorammme she was watching. Has anyone tried it?

normal salt
normal vinegar
warm water from the tap
mix together, put coins in and count to 10


Cheers

 

[SignalFailure]

Depends on the coins firebird - if they are silver just wrap them in "tin foil" (aluminium foil) and drop them into boiling water with a little vinegar for a few minutes. The vinegar is optional as is the water really! Just holding/rubbing old silver in foil will produce heat, lovely sulphery bad-egg smells and a clean coin. I've used the method to delicately clean coins up to 2,000 years old with no ill effect.

 

[AKViking]

As a jewelry artist who works primarily in silver (gold is just too expensive to use much!) and just getting into machining, I've followed the silver soldering thread with interest. Although it may seem counter intuitive, when silver soldering (especially with silver because it conducts heat so well) you want to use a large bushy flame (neutral), not a hot oxidizing flame to solder. You also want to warm the whole piece up to almost the temperature that the solder will flow (the flux turns glassy) before concentrating the heat where you want to solder. If you just heat the spot where the solder is, it will ball up and generally won't want to flow into the joint. Also be careful not to overheat or keep hot too long. Chances are you will burn your flux off and the piece will oxidize and the solder won't flow. When the solder flows remove the heat. A simple bottle propane torch with a bushy flame should provide more than enough heat to solder unless you are soldering something with a lot of mass. Remember, the solder will actually follow the heat so with a little practice you will learn to "pull the solder" into where you want it.

I really enjoy this forum. Keep up the good work everyone!

Chris in Ketchikan, AK

 

[firebird]

Hi Chris

I didn't mention in the above post that the necklace in question is a very fine sort of chain strung with beads of some sort so I couldn't risk a large flame for fear of doing more damage but thanks for the tips anyway

Cheers

 

[rickharris]

Depends on the coins firebird - if they are silver just wrap them in "tin foil" (aluminium foil) and drop them into boiling water with a little vinegar for a few minutes. The vinegar is optional as is the water really! Just holding/rubbing old silver in foil will produce heat, lovely sulphery bad-egg smells and a clean coin. I've used the method to delicately clean coins up to 2,000 years old with no ill effect.

In the UK perhaps use CILLIT BANG (A cleaning agent) the TV advert shows it cleaning a coin in 15 mins. It contains citric acid.