Silver soldering.......a newbe to boilers

[packrat]

The American Native Indians here in the South West USA use a blow tube and burner to silver solder silver rings and such..Very
small parts can heated up that way on a charcoal brick ...

 

[kwoodhands]

Mike,

I think your decimal point is in the wrong place! As for leaks, two thoughts come to mind. the first is to use silver solder paste as a preparatory 'tinning' before actually sealing the joint. 'Tinning' does help and if you are brave and careful enough, removal of the dross can be achieved with a wiping cloth on. Your initial offering should leave everything bright and shiny in preparation for adding to equally important ring of solder. OK, I would use a long stick dabbed iin flux with a bend it to avoid poking my eye out but a ring of solder held by molten clear flux is the beginner's way. You need a steady circular motion rather - dabbing it here, dabbing it there approach. the heat around a tube or stay must be EVEN.

Ken should read the foregoing too!

My dear old father who could barely read and write would tackle a full size locomotive boiler and 'raise the dottle' from out of the weld. This is an old Northumbrian or Tyneside expression about the filthy residue left in a smoker's tobacco pipe and a weld if not scrupulously prepared will have the leaking mentioned caused by dirty inclusions. I'm not going to give a lecture on how to do it suffice to say that this isn't a dirty oily corroded lot of old steel piping and so on.

After all, EVERYTHING should come out clinically clean of a pickle bath ideally of dilute sulphuric acid.

I got carried away with the zeros. Thanks for the info, I printed your post out as your explanation made me think some day I might try again.
mike

 

[John Antliff]

Thank you bluejets for your comment about being available in Aussy. I happened to buy 50 troy ounces of 1/16th inch wire 45% Cadmium silver solder on Ebay a few years ago. I think the unused/unopened box containing 83 meters of wire was being purged from the factory because of the Cadmium content. The price I paid for the entire lot was about a quarter of what I would have had to pay normally and I now have a lifetime supply , enough to make a dozen 6 inch boilers!

I have no idea how my cat Murphy got into the post!!!!

 

[goldstar31]

Apart from the usual perambulations, it is now a moth since the original posting.
following the procedure when I did my City and Guilds, can we learn if there has been any positive results as a result of our efforts, please?

Cheers

Norman

 

[Ken Ratcliffe]

Apart from the usual perambulations, it is now a moth since the original posting.
following the procedure when I did my City and Guilds, can we learn if there has been any positive results as a result of our efforts, please?

Cheers

Norman

Hi Norman - yes is the simple answer. 4" front pressure plate now firmly in place, no leaks evident (so far). I think in the end it came down to not appreciating how much heat was needed in such a large copper tube and the insulation needed. I got a Sievert torch, switched solder and flux as suggested and low and behold it worked. Flushed with success I have got the rear plate ready with phosphor bronze bushing all machined and ready. So maybe tonight, I will be looking to get that in place. In the interim, I have build the fire box and tender, so progressing - albeit solely as I must admit to reverting to a clock build while waiting on materials (a Merlin Band clock).
Many thanks to all useful and interesting thoughts
Ken

 

[petertha]

Another tip is to use Citric acid as your pickling medium - it's cheap and far less dangerous then H2SO4 (Sulphuric acid i.e. battery acid) and it works just as well if not better!

Do you mean buy the flakes & mix with distilled water or something? Or is it a ready-made solution available somewhere?

https://www.amazon.ca/Non-GMO-Proje...0&keywords=citric+acid'&qid=1580328122&sr=8-7

 

[clifforddward]

Sparex brand pickling compound works great on brass/copper based parts....I've found it safe to use and lasts a long time in the 5 gallon bucket I reserve for pickling.

Note you should NEVER put non-brass/copper based parts in the same pickling solution unless you want them to disappear! This becomes important if you are silver soldering steel parts to copper/brass....you will not be able to pickle the assembly...will need to clean the flux via hot water and mechanical means (elbow grease).

Even my hangers for the pickling solution are copper...I used some surplus copper 2 gauge wire I had to make up a handful of "S" hooks I use for hanging parts in the pickle solution.

 

[John Antliff]

You can get citric acid from any Asian foods retailer, I don't quite what they use it fo but it comes as crystals and you make up a solution of approximately 100 grams to the gallon. If you warm it up like any chemical reaction it works faster. You don't need distilled water. It can be stored and reused many times and goes a pretty blue colour as it becomes saturated with copper ions. It is harmful if drunk or spilled onto clothing or skin. Far better than either vinegar or H2SO4.

Your URL shows the correct stuff.

John A.

 

[John Antliff]

Correction to my last sentence " It is NOT harmful if drunk or spilled onto clothing or skin."

 

[awake]

I have bought citric acid in the grocery store, for use in adding acid to pickles or tomatoes or such when canning. I assume it is the same thing - ??

 

[John Antliff]

Yes, that's the stuff.

 

[Roskrow]

I get citric acid from Amazon. Mix with two water and immerse for 30-40 minutes. Rince well in clean water and clean with a small nail brush or an old tooth brush. I do not think there is any fixed amount of acid to water. Just add more acid if needed.
it always works very well. Good luck.

 

[cbwho]

Correction to my last sentence " It is NOT harmful if drunk or spilled onto clothing or skin."

Actually when blue, it's poisonous from the copper.

 

[goldstar31]

I think that some of us are 'making a meal out of this pickling'. My thoughts for what they are worth are to use most dilute acids even to brown sauce and rhubarb leaves.

The only thing that I would not suggest is battery acid taken from old scrap batteries which will coat the metal with lead.

 

[methuselah1]

Personally, for small fittings, quenching in water shifts most of the flux, then citric acid (which works surprisingly well- plus you can make your own sherbet) or even HP (fruit) sauce. I'm sure that phosphoric acid (coca cola) would do the same job.

When these methods work so well, why would I want to keep heavy acids at home?

 

[bobden72]

No one has mentioned it but I always use White Vinegar for my pickle, works well.

 

[wazrus]

Sulphuric acid. I've used the same batch of diluted H2SO4 for years and it still works well. I have a plastic 20L bottle of concentrate, which was bought before all the silly business with 'nasty' chemicals and it's a refresher for the plastic pickle tub. Covering the stuff keeps up its potency and also saves the 'insect soup' of wasps, flies and other creatures. Every so often, I clean out the copper sulphate and it's good weedkiller. I couldn't imagine having to wait 30-40 mins to pickle a small part. I usually dunk 'em as soon as I can: not red hot, but certainly too hot to touch.

 

[Rocket Man]

How do I upload a picture here?

 

[Cogsy]

You can simply 'drag and drop' images into your post as you are composing it and they will upload. They will then show up at the bottom of your post if you do nothing else or alternatively, as you get to the point in the post where you want the picture to appear you click the button next to the thumbnail at the bottom of your post to show the picture full size. It's more difficult to explain than it is to do.

 

[Rocket Man]

I 'drag and drop' images into this box 3 times and they are not here?