Silver Soldering...supplies? tools? etc.

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zeeprogrammer

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Silver Soldering...what an interesting topic. What with Dennis' (4156df) portable hearth, Arnold's current boiler thread, and many other references (tel, firebird, etc)...not to mention my upcoming Toy Loco...I need to learn more.

I've been digging around the internet quite a bit...but am still confused and wanting...so here goes...a mix of what I 'know' or 'have wrong' and some questions. Pile in everyone...no offense if you start a reply with 'You dolt!'...so long as it's aimed at me. ;D (Reply must have more than simply 'You dolt!'...and I see you thinking Vernon.)

For anyone wanting to suggest a brand or something...keep in mind I'm a fine example of a US based newbie.

Silver solder...same as what you find in jewelry supply sites?

Seems to be four kinds...all differing in melt temperature... 'real' easy, easy, medium, and hard.

Main(?) purpose for different temperatures is that it allows you to work in stages in close proximity with previous work. That is, use hard then can use medium close by without melting the hard stuff.

Comes in paste, wire, sheet. Looks like wire is most popular. Can hammer into small thin sheet or chop into itty bitty pieces. Wire (which is what I'm considering) comes in 1 oz rolls for about $20 to $25.

Flux....hm...haven't looked yet.

Some of the wire stuff comes with cadmium, some not. Should avoid? Or use outdoors?

Butane okay for small work, butane with oxy for higher temp, mapp still hotter...mapp with oxy even more so. Danger of melting small parts but more needed for bigger parts.

Firebrick...solderite is about $12 for a 6"x12"...also available from jewelry supply. Can be drilled and shaped. Any thoughts on cool down period?

MAPP...aka Bernzomatic Max Power Propylene? Yellow can.

Assuming I'm right about the source...I'm thinking of getting two spools for learning...one easy and one medium.

Torches! A plethora of choices it seems. Help me narrow it down!

Picking. Right. Well enough for now. We'll get to it.

Pics would be great too!

Sorry...no snacks here.

Thanks all!



 
zeeprogrammer said:
Silver Soldering...what an interesting topic. What with Dennis' (4156df) portable hearth, Arnold's current boiler thread, and many other references (tel, firebird, etc)...not to mention my upcoming Toy Loco...I need to learn more.

I've been digging around the internet quite a bit...but am still confused and wanting...so here goes...a mix of what I 'know' or 'have wrong' and some questions. Pile in everyone...no offense if you start a reply with 'You dolt!'...so long as it's aimed at me. ;D (Reply must have more than simply 'You dolt!'...and I see you thinking Vernon.)

For anyone wanting to suggest a brand or something...keep in mind I'm a fine example of a US based newbie.

BOC or CIG 45% silver.

Silver solder...same as what you find in jewelry supply sites?

Same as wot you find in welding supply places

Seems to be four kinds...all differing in melt temperature... 'real' easy, easy, medium, and hard.

Forget 'em - just get the 45% stuff.

Main(?) purpose for different temperatures is that it allows you to work in stages in close proximity with previous work. That is, use hard then can use medium close by without melting the hard stuff.

See above - the alloy will have a higher melting temp once it's been done and you can usually do the next stage with the same stuff with no trouble

Comes in paste, wire, sheet. Looks like wire is most popular. Can hammer into small thin sheet or chop into itty bitty pieces. Wire (which is what I'm considering) comes in 1 oz rolls for about $20 to $25.

Rolls? Get sticks.

Flux....hm...haven't looked yet.

BOC No.2 Silver Soldering fFlux, or BOC General Purpose ditto


Some of the wire stuff comes with cadmium, some not. Should avoid? Or use outdoors?

Cadmium has only recently surfaced as a 'concern' - mainly in those places that thrive on bureaucratic interference. I've used the cad bearing stuff commercially snd non-commercially for over 40 years with no ill effects. Just don't hold your mouf open over the fumes, or breathe too deeply of 'em.

Butane okay for small work, butane with oxy for higher temp, mapp still hotter...mapp with oxy even more so. Danger of melting small parts but more needed for bigger parts.

All will work - I usually use the outer flame of Oxy/acet uless it is fir tiny bits.

Firebrick...solderite is about $12 for a 6"x12"...also available from jewelry supply. Can be drilled and shaped. Any thoughts on cool down period?

Just untill the soldering alloy has well and truly frozen then drop the piece in water so the thermal shock can remove most, if not all, of the flux residue

MAPP...aka Bernzomatic Max Power Propylene? Yellow can.

Assuming I'm right about the source...I'm thinking of getting two spools for learning...one easy and one medium.

Torches! A plethora of choices it seems. Help me narrow it down!

Picking. Right. Well enough for now. We'll get to it.

Pics would be great too!

Sorry...no snacks here.

Thanks all!

 
Zee
I realise this company is the wrong side of the Atlantic but the information on his site is well worth a look He attends many model exhibitions her in the U.K. and is always willing to help. (And no he is not my uncle) I’am just giving credit where its due.
Dave Bick

www.cupalloys.co.uk
 
Hi Zee;

A few things to get this going;
People often have trouble because they get the wrong kind of flux. I'll just tell you what I use, which works.

For "real" silver soldering, (which is really silver brazing), but we call it hard soldering, get a solder and flux that are matched up and you will have a good part of it licked.

I buy Harris products. They've been in the game a long time. Specifically, I use Safety-Silv 45 or Safety-Silv 56 for hard solder, and use their Stay-Silv White Flux (a paste flux). This flux is made to work with these two solders, among others.
To keep you from having to look all over for this stuff, check here:

http://tinyurl.com/ygxd4qe

It's Home Depot, and they sell 45 and 56 online. Enter solder in the above page and it will take you to a page where you can find 56 also.
45 melts at about 1375 deg. 56 melts at about 1200. So there are two that you can use for step soldering, like when you want to solder something together, and then, later, solder bits onto the same piece without having the first solder job coming apart.

For soft silver solder, which is 95% tin and 5% silver, get some Harris Stay Brite solder. It comes in a kit with solder and the proper flux for it, which is Harris Stay Clean flux, (a liquid flux). This stuff is not for boilers, but works great for joining non pressure items, like building up a crankshaft. It melts at about 450 deg. It's here:

http://tinyurl.com/yg2ytk5

None of the Harris products have cadmium, as far as I know. It's not good for you, so that's probably best.

The three solders mentioned here will all solder copper alloys and steel alloys, to themselves, and to each other.

That's all I've got for now. Have to go.

Dean
 
As with everyone else, I will add a couple of comments. Harris products are available at welder supply stores. I buy it in wire form and make it into the form I need as you suggest.
For model work, my preferred thickness is .031 (1/32" to the welder counter guy) and is not normally in stock. Common stock is 1/16" and 3/32" which is too big for most model joints unless you beat it out to smaller size.
Ebay is a great source for silver solder. When you are lucky you get a 5 oz roll for the usual price of 1 oz. Don't worry if it is old stock and has cadmium unless you are working with pounds of the stuff every day.
Propane or butane is hot enough for all grades of silver solder. The common Berzomatic torch from the hardware store does most of the model work. For really small work, there are small refillable butane torches for less than $15.00. For really big work you need more heat volume (not higher temperature). Sometimes I use two torches, sometimes set the work on the kitchen stove or as a last resort, use the oxy acetylene torch but it is very easy to ruin both the work piece and the solder with too much heat.
 
Great stuff everyone! Thank you.

tel...didn't know about the tip to drop in water.

Dave...good site. I've bookmarked that for more reading.

Dean...very helpful. Home Depot eh? Thanks for the names.

Stan...yeah..I need to use eBay more.
 
Dean and others have covered it nicely. I have used Harris silver solders for years, usually Safety-Silv 45 (and white paste flux.) I personally stay away from cadmium-bearing solders because they cause me respiratory distress.

Although Dean didn't specifically say to use it, I think ANY reference to soldering with any tin/lead/antimony alloy regardless of its silver content should be eliminated from conversations about model boiler construction, except to say these have no place in model boiler work. 5% silver-bearing solder is not silver solder although the packager wants you to think it is. I know it's easier and more convenient and cheaper than silver soldering, and within the confines of your own home or shop or yard you can build a boiler any way you want, but the rest of the civilized live steam world abandoned soft solder for boilers at least 75 years ago.
 
Thanks Harry. Very worthwhile reply.

On that note...is the 45 or 56 appropriate for building the kinds of boilers I'm interested in? My dream is to eventually build a 3 1/2" scale gauge loco.

On another note...cadmium and other dangerous metals have been mentioned in the context that it's okay to be exposed to them when working small jobs and/or having minimal exposure. I don't necessarily disagree with that. However, let's not downplay the danger. At my age I'm willing to take certain risks that I don't want my children to take.

 
Carl,
Do you mean 3.5" GUAGE loco? The answer is yes, any 45% silver solder by reputable manufacturer will be appropriate for all model boiler building up to the maximum reasonable size. I don't know what the largest model copper boiler ever built is but I know of 12" boilers built in England. Here in the US we usually change over to steel above 6". The largest one I have built was 6". The overwhelming majority of boiler builders use 45% silver and while there might be a small difference, maybe even an advantage to 56% I don't know what it would be. I've never bothered to compare their characteristics and behavior.

On cadmium, . . . as has been mentioned some manufacturers have discontinued it, and I'm sure they have good reasons for that. There is at least one fellow in the US, who is a superb craftsman, who actively promotes cad-bearing solders because he insists that because they flow more freely (that's why the cadmium is added) they are better for amatuers to use, make better joints, etc. That's debatable. Over a long period of time I've used both, and I'm healthy as a horse. But even with an outdoor brazing hearth cad-bearing solder will, as I mentioned, cause me respiratory distress and for me there is not enough actual difference in their flow characteristics to expose myself to that. It's a personal choice.

Harry
 
I get silver solder and accessories from SRA-- http://www.sra-solder.com/

You probably want the BAg-1 composition-- that's the same as 'EasyFlo' you may read about (has Cadmium). I've tried the Jewelry supply silver solder and it works as well, but requires quite a bit more heat and doesn't flow as well. I like the 0.031" wire. Works great for the preformed solder ring technique, which is nice and easy for round parts-- clean the solder. clean the parts. make a wire loop of solder to go where the joint will be. Flux the parts, flux the solder. Apply lots of heat to the parts (_not_ the solder or flux-- sometimes this is the trickiest part). Heat the heck out of the parts. About the time the parts are the color of cooked carrots, giving off enough light to see by and you're sure you've been scammed by somebody selling you steel wire instead of solder, it will melt and flow like gasoline.










 
Zee, I would like to add a little to what Harry mentions, and to make something clear, so what I wrote is not mis-taken.

Specifically, I mentioned that the 95% tin/5% silver solder is NOT to be used for boilers. It is called silver bearing solder, and it is actually silver solder in every sense of the words. It's silver solder.


The 45 and 56 (45% and 56% silver, respectively) solders I mentioned are commonly called solder, but are, by definition, not solder at all, but brazing alloys. We call them hard solder, or silver solder in the USA, and that is the common usage of those terms, though they are misnomers as far as the "solder" part goes.

These previous two paragraphs are not meant to disagree with Harry on boiler building. He knows his onions from his turnips when it comes to that! Just want to clarify definitions, in case it matters.
Anything done at below about 800 degrees is soldering. Anything done above that, but before the base metal melts, is brazing, for our purposes here.

If you go to a welding supply, which is where I get my stuff, and ask for silver solder, you may get real solder, which is always soft, or you may get hard solder (brazing alloy), which is what you want for boilers. At a welding supply shop, ask for 45% silver brazing wire or coil, and you will get what we call "hard solder". These can be marked down as semantics, but knowing what you want, and knowing the difference when the guy hands you a product may help if you have to ask someone at a welding supply.
I ask for the product by brand name, to eliminate confusion, (including the flux).
Get the stuff from the Home Depot links, and you will be getting the same thing that Harry and I are recommending.

I don't think the classifications that Tel refers to are applicable here in America. They are probably the same things we use here, but the welding supply shop guy won't know what it is. If you want to ask for 45% silver solder by it's classification, ask for BAg-5 wire, rod, or coil. If you want to do the same for 56% solder, ask for BAg-7. Those are the America Welding Society's class numbers, and are always constant in any state in the union. You still have to ask for flux. Get Harris Stay-Silv White Flux. If you just get "some" kind of white flux, and you have trouble when first trying this, you will never know if it's you, or the flux! Start out with the right flux, and eliminate that variable.

It may sound like I'm big on Harris products. I was a welder for nearly 25 years, and used a lot of different stuff. Harris makes a good product, and you will find their brazing alloys, (hard solder) in most welding supply shops. Other companies make them too, but you always know what you are going to get with Harris. Other companies make alloys, but may not make a flux to match it. The Harris products are matched up, saving you from hunting down a proper flux for your alloy.

By the way, when "hard" solder is mentioned in threads here, it's not because it's hard to use. It's because it makes a hard bond. Higher tensile strength, and all that stuff. I don't think "easy" and "medium" really fit. There's regular soft low silver content solder, which works the same way as high silver content solder, but melts much lower, which seems easier, I guess. It's also much weaker, of course.
"Hard" solder works the same way, but has to get three times as hot to work. I use a propane torch, or two, and sometimes use one of them with MAPP. The ones I use are the regular Bernzomatic types.


Dean
 
Jewelers rank solder by "Easy, Medium and Hard". That only refers to the melting temperature, the idea being if you have to heat a part multiple times, you start with the highest melting point solder and work down each time. With most model engineering, the parts are big enough it's not an issue, but do re-flux existing joints before heating for a new one.

 
Thank you shred.
Thank you Dean.

Those were great posts. I'm going to bet that a lot of people are going to find that information very helpful.

Deanofid said:
I ask for the product by brand name, to eliminate confusion,

You're talking about the supplier but it relates to why I ask the questions I do...

I'm a professional newbie. (Aren't we all?) ;D Give me the hard, clear example first...let me learn from that...and then I can grow and learn to choose between brands (or methods, or teachers,....



 
Carl,
The silver braze that I use is Harris Safety-Silv 56 with the Stay-Silv white braze flux. Mostly I use 1/32 wire, but I use some 3/64 wire. I build small parts so the small diameters work better for me. I have used 1/16 diameter for small Gauge 1 locomotive boilers.

All the Safety-Silv line is cadmum free. According to Harris, the alloys without cadmium take about 10 to 15 percent more silver to have the same flow as alloys with cadmium. The 56 percent silver with out cadmium flows about the same as the older 45 percent alloys with cadmium. It does take a slightly higher temperature, but nothing serious.

I buy mine from:
https://weldingsupply.securesites.com/cgi-bin/einstein.pl?Next::1:UNDEF:OR:terms::PF#F5

56150 SF56-1/32 - 1/32 (Cut From 50 TO Coil) $21.58 18% Off Details $17.65 1/TO
56250 SF56-3/64 - 3/64 (Cut From 50 TO Coil) $31.15 47% Off Details $16.46 1/TO
40021 Stay-Silv White Brazing Flux 1/2 Lb (SSWF1/2) $6.37 38% Off Details $3.95

I have used them for years. They have things in stock and ship quickly. Prices are fair also. My local distributor does not carry any thing smaller than 1/16, although they will order it for me.

Their web site has a lot of useful information on the various alloys also.

Gail in NM

 
Deanofid said:
Specifically, I mentioned that the 95% tin/5% silver solder is NOT to be used for boilers.
And so you did, sorry for that oversight.
 
Zee, here's a site you might want nose around. It's not about how to actually do silver soldering, but has a lot of info about processes and the various alloys and flux. In particular, check the link at the top that says "support" and then on to "filler metal chart". The filler metal chart tells the various alloy compositions and their flow rates and melting temps. FYI, flow rates of 6-8 work well for us types.

You will see the Safety-Silv 45 hard solder that some of us have been talking about in those charts. You will also see one called StayBrite, which is a soft silver solder. If you haven't done any soldering, or none on dissimilar metals, think about getting one of the StayBrite soft solder kits too, for practice. That kit is under $10, and will help you learn what to watch for. It works very similar to hard solder, but at a lower temp, and is cheap enough to use up the whole thing in practice. I don't mean the StayBrite is a replacement for the Safety-Silv 45 or 56, but it acts similar to learn a few basics.

http://www.harrisproductsgroup.com/faq.asp

Harry, no problem. Just wanted to clarify.


Dean
 
Thank you Gail, Dean, and Harry.

My apologies that everyone will have to wait so long until they see the fruits of their labor (teachings)....but it will come.

I've done a lot (a lot!) of soft soldering (all electronics) and some bit of plumbing work...I suppose that gives me some idea of what to expect. At least I know (I think) what you mean by 'wicking' and 'flow'. So maybe I'm making more of this than I know.

Anyway...can't wait to try it. Hopefully I can order some supplies tomorrow and start experimenting.
 
Carl: If you have done soldering on copper pipes it is the same process, just higher temperature. Odd shapes, with thick and thin sections and small parts is where the learning curve really starts.
 

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