# Silver Soldering...supplies? tools? etc.



## zeeprogrammer (Dec 27, 2009)

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!


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## tel (Dec 27, 2009)

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.)
> 
> ...


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## d.bick (Dec 27, 2009)

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


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## Deanofid (Dec 27, 2009)

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


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## Stan (Dec 27, 2009)

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.


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## zeeprogrammer (Dec 27, 2009)

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.


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## GWRdriver (Dec 27, 2009)

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.


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## zeeprogrammer (Dec 27, 2009)

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.


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## GWRdriver (Dec 27, 2009)

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


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## zeeprogrammer (Dec 27, 2009)

GWRdriver  said:
			
		

> Do you mean 3.5" GAUGE loco?



Yes! Thanks. I've modified my post.

And thanks for the clarification.


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## shred (Dec 27, 2009)

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.


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## Deanofid (Dec 27, 2009)

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


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## shred (Dec 27, 2009)

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.


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## zeeprogrammer (Dec 27, 2009)

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,....


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## GailInNM (Dec 27, 2009)

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


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## GWRdriver (Dec 27, 2009)

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.


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## Deanofid (Dec 27, 2009)

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


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## zeeprogrammer (Dec 27, 2009)

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.


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## 1hand (Dec 27, 2009)

Zee

Whats your torch set-up going to be? I have yet to buy one. I see in the plans for the up coming frist engine I will need to solder some stuff. I been looking into the Turbo Torch made by Victor.

http://store.cyberweld.com/tuexseigprto.html


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## Stan (Dec 27, 2009)

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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## Stan (Dec 27, 2009)

1hand: That is a nice looking torch and for $300.00 I would expect it to be. For home shop use, it does pretty much the same job as a Bernzomatic with a bottle of propane for $14.00.


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## 1hand (Dec 27, 2009)

Cool.
I got one of them. Probably try some map gas.


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## bentprop (Dec 27, 2009)

Just a thought,zee,if you've never done any hard soldering/brazing,definitely try it out on a few bits of scrap,before trying to solder up that thingummy that took you 7 hours to machine.
Also,not usually being in much of a hurry,i chuck the soldered bits in a small bucket of citric acid mixture for an hour or so,2oz. to a quart bucket.This gives a nice clean surface,which just needs a quick flick with a soft brush,and you're ready to do the next bit.
In relation to the "big parts to small parts",always heat the larger part the most.Generally,the heat will flow onto the small part.
Have at it,son,it's all good fun.


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## arnoldb (Dec 28, 2009)

Zee, my half cent's worth from a newbie....

First up, pickle; like bentprop mentioned, citric acid works well to clean the parts. It is also non-toxic, cheap, and easy to dispose of when you need to. It is safe to use around other people (and pets) and you don't need oodles of protective clothing while using it. In fact I use none; not even gloves, and take parts out of the pickle with bare hands; it does burn a tiny bit if you have any cuts on your hands though, so some consideration is worthwhile for gloves.

I found dunking the workpiece straight into the pickle bath after soldering really helps to clean it up quickly. I would NOT recommend doing this with commercial pickling agents or acids other than the citric acid! - You will get some splashing & vapors coming off. A clean toothbrush helps with additional scrubbing.

Having gone through this thread, I see where some of my soldering woes stem from; I have 40% silver, cadmium free rods, so that means my parts must get to a much higher temperature for the solder to flow than if I had 45% or higher silver content rods. Well, the 40% is all I could get my hands on here in Windhoek, so I'll have to make do. You should have a lot less problems if you can get higher silver content rods/wire.

A tip I can give you: I have been inclined to use way too much solder in previous ventures. You need just a light dab of the rod - I got some practice with this yesterday with the boiler; all in all I used only about 150mm of a length of 1.5mm solder rod for all the work I did... And the process seems to get easier the more I do it 

Regards, Arnold


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## PTsideshow (Dec 28, 2009)

Here is a new torch that is less than $100.00 and comes with either a bulk Propane cylinder fitting or disposalable cylinder.
















EZ torch kit page link
I believe it is also called the shark, it is sold as a student jewelry toch and it works very well for silver soldering at a low start up cost.

















The adapter will connect a standard hose or torch fitting to a bulk cylinder, with the addition of it and a hose from a BBQ and a torch head you can have a long reach torch.


This is the gentec version of the turbo torch for propane, They also have acetylene/air torches, but require the purchase of one of these.











The prest-o-lite type/style torches are made by 6 or more companies most of the parts interchange on the old ones.I don't know about the new quick disconnect ones.
If you go the air acetylene route you will also need an adapter from cylinder to regulator





Bernz-O-Matic web page

 More silver brazing from the company that makes the filler rod

Power torch catalog is the one you want

Gentec torches

Turbo torch home page

Goss brand of torches

Uniweld brand

Brazing book Handy and Harman

The flux chart from the book great to bookmark too


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## firebird (Dec 28, 2009)

Hi

I bought this kit from machine mart, ( I believe they are a subsidiary of a US company)

http://www.machinemart.co.uk/shop/product/details/fc109-gas-torch-with-nozzles

Cheap and cheerful but so far I have done all my silver soldering with it including both my boilers.

One of these will silver solder small parts as well as long as they are in a hearth.






Silver solder wire is ideal for snipping small bits off and placing in the flux.

I also have a small pencil torch that will silver solder small parts, both these are filled with cigarette lighter refill gas.

Cheers

Rich


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## zeeprogrammer (Dec 28, 2009)

This is great information everyone. Awesome. I'm particularly happy that it seems to be helpful other members as well.

Thanks!


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## GWRdriver (Dec 28, 2009)

> Having gone through this thread, I see where some of my soldering woes stem from


Arnold,
Sorry to hear you have woes, but to follow up on your comment, the VAST majority of silver soldering problems for amatuers come from three sources, in order, (1) not enough heat, (2) contaminated surfaces or poor preparation in general, and (3) not enough heat.

I have two types of heating gear, which I chose by default, meaning, OK I've got this gear let's see how it will work for building boilers. So far so good. The first is a standard full size oxy-acetylene setup with a 1" "rosebud" as my primary boiler building tip, and then I have a propane setup using bayonette torch tips much like those illustrated in PTslideshow's post. I like them both and use them both. The warnings we've all gotten for using oxy-acetylene on small copper and brass assemblies (boilers, etc) are justified because the melting temperature of copper and brazing solder aren't very far apart and in a moment of inattention it's not difficult to burn a hole in something. I've done it to myself (well, a boiler part) and I learned to pay attention and make the gear do my bidding and no more. The rosebud tip (and some discipline) allow me to use oxy-acetyle for a big job without being afraid I am going to incinerate something. The propane gear I use for small boilers and its greatest attributes are that it's gentle and controllable, . . . and late on a Saturday night, if need be, I can get more fuel at the Minute-Mart!
Harry


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## Stan (Dec 28, 2009)

Harry: I never had to go as far as a 1" rosebud to silver solder but I am a non conformist. I use a propane cutting tip on my oxy torch and since the torch is mainly used for cutting it usually has the cutting torch hooked up to propane. With the propane cutting tip I use a large soft flame when I have something big to silver solder.
It is much easier to control the heat than with an acetylene welding tip.


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## shred (Dec 28, 2009)

I'd suggest a major beginner error is "flame applied directly to flux and/or solder".


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## GWRdriver (Dec 28, 2009)

Stan  said:
			
		

> Harry: I never had to go as far as a 1" rosebud to silver solder


The rosebud came with the set so I made use of it but I've never had it past about half throttle, it gets pretty hot standing close to it at that.


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## arnoldb (Dec 29, 2009)

Harry, thank you, and you are right about the heat. 
I've had problems with the heat, but things are improving for me though, I am happy to say. My current boiler build is going well, and I am getting a feel for when things are hot enough, and just as importantly, for controlling where the heat must go. 
So I think my woes are pretty much something of the past - I'm actually starting to enjoy the whole process .

Regards, Arnold


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## Chris AW (Jan 23, 2010)

Does anybody know the correct gap for Safety Silv 45? Harris' spec sheet just says 'wide clearances'. 

Thanks,

Chris


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## steamer (Jan 23, 2010)

Well....without a "for instance"...I would say up to .02 max

Really intended for .004" or even smaller....especially high strength applications...

Dave


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## GWRdriver (Jan 24, 2010)

steamer  said:
			
		

> .I would say up to .02 max


Dave,
I don't know if I would be bold enough go public with a figure like .020", I'm not sure what the widest clearance I've asked it to bridge is, probabaly not near that much, but I agree that Safety-silv 45 has the ability to fill quite a bit more gap than the mfg's allow . . . but isn't that the case with many products. The problem with excessive gaps is $$$$. Large gaps can wick in many times the amount of solder actually required to make a sound joint.


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## Blogwitch (Jan 24, 2010)

I almost always use the ring/flux/wicking principle if possible. I have found the ideal gap to be around 0.002" to 0.003" (or metric equivalent).

Heat only the major part of the construction, the heat transfer will automatically warm up the smaller parts, and use only enough rings of solder wire you think will be needed to fill the joint completely. Always err on the side of overfilling. I have found that to fit say a 1/8" copper pipe into a 1/8" depth of hole will require one ring of thin wire, that gives good penetration and a nice outside fillet. So for the same sized pipe going into a 3/16" deep hole, I would put 2 rings on to make sure of a good joint.

For compression joints, I normally use the wire down in the bottom of the joint to ensure there is a good strong joint made where it needs to be. See attached C-o-C.

Blogs


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