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

[timo_gross]

Just my uneducated comments. I do not know what I am talking about, so I should not write this.

Above said applies, if mixing stuff it seems not easy to tell what happens.
If e.g. Oxygen and Iron are mixed a long time at room temperature. The Oxygen stays were it is even at temperatures much higher than O2 boiling point ( approx. -180°C ).
The Oxygen just disappears out of the gas mixture.

Googling "Vapour pressure of Cd in Cd-Ag-Alloys" brought me a link. Maybe it is a start point, if someone wants to find out more.

Unfortunately I was not able to access the article, because maybe the answer is hidden in it.

Boiling Point is also not the most critical factor. If you place some water in a pot somewhere it will not boil but slowly move into the gas mixture around it. ( no need to boil it for getting vapours ).

For me as not English speaking person. What would be the difference between vapour and steam?

Greetings

 

[peterl95124]

wow, thanks for the info, somehow I missed this detail in college physics and chemistry.
anyway, back to cadmium. I don't use cadmium silver solder, I don't use thoriated tungsten TIG, I don't use Tapmagic-for-aluminum only regular Tapmagic, I don't use insecticides or herbicides in my yard. Etc. If you want to live a long life every little bit helps.

 

[Ken Ratcliffe]

Hi All...…..I started this post quite a few weeks ago fretting about not being able silver solder a large boiler. Having seen lots of good advice and realised that (as always for me) I started with a big job instead of starting simple and working up, I can now say that silver soldering really isn't that difficult, provided you clean the piece, have the right space between surfaces, use the right combo of solder and flux and get enough heat on the piece in a reasonable timeframe. Well on my way to building a steam engine now

 

[tim9lives]

I’ve done a number of projects where I use 45% and 56% silver braze/solder. And never have I been successful with butane or map. I know I’ve seen people do it on YouTube. But they must be better than I am because the only way I have been able to silver solder anything was with Oxy Acetylene. Plus, I’ve had better success with the black flux than the white silver brazing flux. The black is a pain to clean, but it has a more forgiving range IMO.

by the way... Florins according to the wiki page I just looked at say they are 92% silver and remaining cupronickel. So I’m guessing they have some nickel which would definitely make the melting temp a little higher than most silver solder. But that depends upon how much nickel.

For what it’s worth.... here is a post I found a number of years ago when they wanted an arm and a leg for silver solder. This was posted on a jewelry forum... I think.
USA coin melt recipes for making ones silver solder.


Silver solder braze coin recipe

These alloys are safe to use for food handling items, and are also standard alloys for temperature step brazing in silversmithing.

51.5% silver easy braze: Melting point ?
Silver 51.5%
Copper 25.5%
Zinc 17%
Tin 6%
Made from: 1 quarter, 1 dime, 1 pre 1982 cent, 1 post 1982 cent, 15 grains (0.97 gram) tin

56% silver easy braze: Melting point solidus 1145 to liquidus 1205 F
Silver 56.152%
Copper 22.085%
Zinc 16.471%
Tin 5.292%
Made from: 5 quarters, 7 dimes, 4 pre 1982 cents, 5 post 1982 cents, 67.5 grains (4.4 grams) tin

65% silver braze: Melting point solidus 1240 to liquidus 1325 F
Silver 65%
Copper 20%
Zinc 15%
Tin 0.0%
Made from: 4 quarters, 11.5 dimes, 3 pre 1982 cents, 4.5 post 1982 cents, no tin

70% silver braze: Melting point solidus 1275 to liquidus 1360 F
Silver 70%
Copper 20%
Zinc 10%
Tin 0.0%
Made from: 9 quarters, 1 dime, 3 pre 1982 cents, 3 post 1982 cents, no tin

75% silver braze: Melting point solidus 1365 to liquidus 1450 F
Silver 75%
Copper 22%
Zinc 3%
Tin 0.0%
Made from: 14 quarters, 1 dime, 5 pre 1982 cents, 1 post 1982 cent, no tin

90% silver braze, industrial use only. Melting point 1640 F
Silver 90%
Copper 10%
Any pre 1965 U.S. silver coin

 

[awake]

Do any current US coins have any actual silver in them? I had long assumed not ... ??

On edit: it appear that there is no silver in current US coins: https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications

 

[wazrus]

Butane/air simply doesn't have enough heat. Air/propane just makes the grade, in larger work but bigger torches - much bigger - are required. Silver brazing doesn't mind whether the flame is oxidising or carburising, so I use oxy/propane, which is often used in general cutting in industry, as it cuts cleaner, so they say, but the big plus is the cost of the propane. Bottled oxygen can be pricey, but the larger the bottle, the better. My brazing sessions are four-handed and usually, there are two very large air/propane flames and one smaller oxy/propane long-lance burner (the longer, the better) with the alloy and another long oxy-propane heating tip, with the boiler in a cradle of firebrick. Silver rod of 45% Ag content, borax flux, followed by a sulphuric acid pickle. By the way, I do routinely flame-cut my railway wheel blanks from 3/4" (20mm) black steel bar with oxy-propane. I'd recommend Alec Farmer's model boilermaking book.

 

[Shopgeezer]

I checked Amazon for Alec Farmers book. One was listed for over $500 and another for over $2000. Just ridiculous. Are these people serious or is this a joke?

 

[werowance]

Do any current US coins have any actual silver in them? I had long assumed not ... ??

On edit: it appear that there is no silver in current US coins: https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications

you are correct that there is no silver in US coins any longer (to my knowledge) but I still often find silver dimes. you can really tell the difference in sound when you drop one on a granite or marble counter top or floor. you can also see a difference but if you have a coin jar like I do where I drop my pocket change when I get home from work. when I empty it out I drop the coins on a marble tile I have to sort and count them. when I was 19 my first job away from the farm was as a part time bank teller and we had marble countertops which is where I learned to count coin like that. point being is silver dimes are still in circulation and fairly easy to come by in the USA.

editing post - when I say no silver in current US coins I should have said "newly minted" us coins. but there are lots of old coins still in circulation

 

[awake]

Interesting! I don't have any marble, but do have granite; would that also give a difference in sound? I'll have to try it ...

 

[goldstar31]

I checked Amazon for Alec Farmers book. One was listed for over $500 and another for over $2000. Just ridiculous. Are these people serious or is this a joke?

§

Laws of Supply and Demand- and just how much the Market wii stand;

It may not what people like but the Mona Lisa was painted wit a few pennorth of homemade paint but enter the real world of commerce.

Yesterday, I picked up a request for someone who wanted to 'improve' a Quorn tool and cutter grinder and I had bought spares for £70 and re-offered them a the same price for collection. The guy dithered and whatever and whatever and I wished that I had offered the part set at £700.
I finally lost my temper as I was going to donate things to charity anyway.

The castings are now awaiting collection by the refuse man.

Norman

 

[awake]

Norman, I hope that last line is tongue-in-cheek? If not, let's talk about the price of shipping from UK to US!

 

[werowance]

Interesting! I don't have any marble, but do have granite; would that also give a difference in sound? I'll have to try it ...

I would say it does. my ceramic kitchen tiles make a much different sound when a silver dime hits them compared to a regular dime.

when looking through your change sort out all your dimes, a silver one of course has a more of a silver color so its visibly different but also looking at the edge of a normal newer dime you will see a copper looking band where its a "clad" coin (I think that's the right term) but if you locate one you think is maybe silver just drop it on something hard then drop a new dime. you will definitely hear a difference, I can also feel and hear a difference as I am dragging the coins while counting them. dragging from a pile across the marble tile into my free hand until I have counted enough for a roll.

 

[wazrus]

I checked Amazon for Alec Farmers book. One was listed for over $500 and another for over $2000. Just ridiculous. Are these people serious or is this a joke?

That's A pretty alarming price! Have a look at ABE books: I just did and they seem to have lots of copies ranging from about $20. Come to think of it, I seem to recall that ABE is part of Amazon. I wonder how that works?

 

[goldstar31]

deleted

 

[yelcho]

you are correct that there is no silver in US coins any longer (to my knowledge) but I still often find silver dimes. you can really tell the difference in sound when you drop one on a granite or marble counter top or floor. you can also see a difference but if you have a coin jar like I do where I drop my pocket change when I get home from work. when I empty it out I drop the coins on a marble tile I have to sort and count them. when I was 19 my first job away from the farm was as a part time bank teller and we had marble countertops which is where I learned to count coin like that. point being is silver dimes are still in circulation and fairly easy to come by in the USA.

editing post - when I say no silver in current US coins I should have said "newly minted" us coins. but there are lots of old coins still in circulation

Seem to remember (unreliable) that a few years back in the UK when silver went sky high on metal markets that bank tellers were sorting silver coinage by date because older coins had higher melt value than face and selling to silver smiths in lunch hour. could be urban myth since same dodgy memory suggests some ancient law against melting currency.

 

[peterl95124]

I have Kozo's "Pennsylvania A3 switcher" book, it has an excellent chapter on silver soldering a boiler (IIRC and appendix on silver soldering technique). I highly recommend the book for this and many other reasons, not only is the A3 Switcher a work of art, the book itself is a work of art.

my best one-piece-of-advise, for something large like a boiler is get some thermal wrap, I found some at Home Depot sold for use as a thermal barrier between the pipes and the wall when doing plumbing soldering.
It looks like 1/2" thick black felt but is totally flame resistant, I bought several pieces in spite of the cost. I wrap my boiler in it and then wrap that in stainless foil, before silver-soldering anything, otherwise the copper acts like a giant radiator and makes it impossible to reach silver solder temperature anywhere. Even with the thermal wrap it takes a long time to reach temp. I use MAPP gas because it has three times the heat energy as propane. But my guess is that MAPP is dirtier than propane, I think it contaminates and deactivates the flux (I'm guessing it sucks out the fluorides) so I use it for heating the boiler in general, and use propane at the same time for heating the area where I'm actually silver-soldering.

HTH, best.

 

[TRIPLE]

That's A pretty alarming price! Have a look at ABE books: I just did and they seem to have lots of copies ranging from about $20. Come to think of it, I seem to recall that ABE is part of Amazon. I wonder how that works?

https://www.bol.com/nl/nl/p/modellbau-modelldampfkessel/9200000121686819/
When it is possible to translate an E-book from German to Englisch this is a book from a German modellbuilder. I make the two firepipe Schottisch boiler like on the frontpickture of the book, its a great book and there are severall boilers to make.
bol.com is a Dutch onlinestore so I don't know if they sell to the USA.

 

[werowance]

Do any current US coins have any actual silver in them? I had long assumed not ... ??

On edit: it appear that there is no silver in current US coins: https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications

Awake, yes you are correct that none in current mint (that i know of) however silver dimes are very common still to find in circulation. learned from my first job that wasnt farming as a teen, i was a bank teller (and not a very good one either) and when a silver dime hit the marble counter top to be counted i could hear that distinct sound and could easily pick out the silver ones. still today when i have to empty the pocket change jar and wrap them up, when they hit the kitchen counter top i hear that disticnt ping and i push those silver dimes off to the side. no i have never tried soldering with them or anything, just save them for the silver.

 

[Daryl_bee]

...snip ..Interestingly, in your alcohol/water example, the ethanol (drinking alcohol) has a boiling point of about 78.4 C and water at 100C but a water/ethanol mix has a boiling point of about 78.2C. So when distilling spirits, the azeotrope (around 96% alcohol and 4% water) boils out at lower temperature than either constituent on its own could. The azeotropic behaviour can go in both directions depending on the constituents, which means the boiling point of some substances can be (sometimes significantly) higher than any of the components...snip....

Sort of. A water ethanol mix has different boiling points depending on the mix

I think this curve says it all. 100% water on the left, 100% alcohol on the right, a mixture in between (% on bottom)

Take a 10% wine or beer (bottom), go straight up to the blue curve and see that a "water mixture" at 10% alcohol content boils at 93C. Now, from there, go horizontally across to the red line then straight down from the intersection and you will see that boiled vapour mixture (pot still) will condense down to about an output of 54% alcohol content (given a 10% input).

If you have a column still then, from that previous red intersection, you'd go down to the blue line (note the higher alcohol mix now boils at a lower 82C) then horizontally across again to the red line and down to the blue for the 1st plate (80% output), repeat for 86% on the 2nd plate (80C boiling), etc etc. With more plates you'd zig-zag across getting higher and higher outputs until you got to the azeotrope limit at about 96% (after about 6 or so plates) & 78.4C.

Tomorrow's lesson for "keeners" is on Soxhlet Extractors and Rotary Evaporators. :-D