Need some help sourcing silver solder.

[Brian Rupnow]

On my steam engines, so far, I have been using a free peice of silver solder and some paste that I wheedled out of one of my fabrication shops. I used it up completely on the beam engine I just finished, and now I need to buy more. It is about 1/16" or less in diameter, and I don't know if it was even the right stuff for building steam engines or not, but it worked for me.I see on the internet that there is something called "Easy Flow" silver solder with a much lower melting point, but perhaps it is for jewelry making. There is another one called "Stay-Brite". can somebody please tell me what kind I should be using and if possible, where to get it in Ontario, canada.---Brian

 

[Bernd]

Hi Brian,

A while back I got my silver solder at a welding supply outfit. It's Harris Saftey-silv 45, melts at 1370 degress F. It's 1/16 in dia. It workd good for what I do.

Regards,
Bernd

 

[Brian Rupnow]

I just bought a roll of silver solder at the Praxair dealer in Barrie. It is called "SILVALOY" and is designated as being "Cadmium Free". It is number A45, Part #57304. Not cheap--about $100 for 5 ounces of 1/16" diameter wire. I just tried it out in my garage on some bronze steam engine parts, and it works fine.---Brian

 

[GailInNM]

Brian,
Probably the two most popular silver brazing alloys for model engineering are 45% silver and 56%silver. The 45% silver will form better fillets than the 56% and fill loose fitting joints better. The 56% silver flows into tight joints better and the working temperatures are about 100 degrees F lower than the 45% silver. There are other differences also as far as plastic range and color. The 45% will match the color of brass better and the 56% will match steel and stainless better.

I like the 56% silver the best for smaller parts because of the way it flows and the lower temperature. Joint strength is similar on both.

The Stay-Bright and other low temperature silver solders are really a soft solder with a small amount of silver added. They do not have too much application in most model engineering as they are much weaker than the high silver content silver brazing alloys.

Harris is the leading supplier of silver brazing alloys. The Saftey-Silv 45 that Bernd mentioned is a 45% silver. I use Saftey-Silv 56 which is the 56 % product of Harris.

The international designations for the two products are BAg-5 for the 45% and BAg-7 for the 56%.

Many welding suppliers have or will get the Harris products, and it should not be a problem for you as they supply internationally. The big problem is getting the smaller diameters. Most suppliers only carry the 1/16 inch diameter and I like 1/32 and 3/64 diameter.



Gail in NM,USA

Edit: Brian, I saw that you posted while I was typing. I am posting anyway as the information may help others. The solder you got will work fine. About $20 per troy ounce is the going price everywhere.

 

[mklotz]

When silver soldering small parts, I use a technique employed by some jewelers. Flatten the solder on a clean anvil and then cut tiny pillions from the flattened portion. Using tweezers, I dip these pillions in flux and then adhere them to the (already fluxed) parts before applying indirect heat with the torch.

This technique has the advantage of limiting the amount of solder applied, thus avoiding sloppy-looking joints and runoff.

 

[CrewCab]

That sounds expensive Brian .............. even by Rip of Britain UK Standards ........... For example .............. then again I expect 5oz will get you about 40 - 50 metres (....... about 150 foot ;D ) ............ so it should last a while

CC

 

[Stan]

Brian; The stuff you got will work fine for most of the model work you do. The cadmium free stuff is the latest model to meet new regulations since someone decided cadmium was a carcinogen. I don't have any fear of the cadmium in the small exposure we face as model makers. As Gail mentioned, the smaller diameters is hard to find. I found ebay to be a good source for silver solder if you watch for the 5 oz rolls and not the 5' pieces.
This year I made three buys of 5 oz rolls (1/32",1'16" and 5/64") all under $40.00 each. This is one place where shipping cost is effective as USPS from the US to Canada is under $3.00. Like always, make sure the seller is not trying to make a large profit on shipping and handling charge.

 

[shred]

I priced a little silver solder (40%+ silver-- the "silver solder" at the hardware store is 5%) not long ago. 1oz is about $35 or $40 at the moment.

Easy-Flo has cadmium in it and costs a little more. Jewelers supply places can sell you sheets or wire, plus appropriate flux, though they may not be the cheapest source around. They tend to have 5 grades-- Soft (ordinary solder.. you don't want that). Hard, Medium and Easy, plus Easy-Flo. H, M and E have lower melting points as you go down the scale-- that's so you can solder on already-soldered pieces if you use a notch cooler solder and take it very carefully. Easy-Flo has a melting point somewhere between Easy and Medium.

 

[Mcgyver]

easy flo 45 in 1/32 dia coil is the beautiful stuff to work with. as the guys have said, you'll find it at welding supply stores. Being in a position of experience using the 1/32 dia, if i ran out, i'd phone until i found it, ie the 1/32 is import to how i use it

Why is it so great? imo the best way to silver solder is to assemble everything with lots of flux and place a small piece or two of the 1/32 silver solder at joint in the flux. warm everything up, being careful not to let the propane flame blow the SS away and, using the melting flux to help hold it in place, bring both pieces to temp at about the same time and the little piece of SS will wick in perfectly leaving no unsightly globs of solder. This is the method advocated by Kozo Hiraoka and is the best way I've found to create a clean, professional looking job.

here's a pic showing a joint ready for heat

and here's the result. in this single SS assembly there were 5 SS joints.

holding everything in place for SS is very important. Detesting those useless, awful little third hand things with the alligator clips i made this gangly system of arms and whatnot to hold stuff in position for SS'ing. I still want to adopt Marv's design into some accessories for it

didn't mean to turn this into a lesson, i know you're just looking to source, but you might not see the value of the 1/32 size without seeing and understanding the technique. hope that helps

 

[Stan]

Harris is the most common brand of silver solder, although there are others. Their web site has a lot of useful info. Look under the button 'alloys' for a wealth of info.

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

Keep in mind the end use of the product. They make "silver solder" to solder copper water pipes together, to solder high pressure air conditioning tubing, jewelery manufacturing and even soldering brass to steel. The secret is to select a product that will do your job with the equipment that you have to work with.

 

[Brian Rupnow]

What is the preferred heat source for working with silver solder. I have been using my oxy acetylene rig with a small torch tip, but it will just as happily melt my brass partsas it will the silver solder.Can I get away with using an ordinary propane torch instead?---Brian

 

[Bernd]

A propane torch such as used to solder copper piping will work fine. But a lot depends on how big a part is. Since the bigger the part the more heat you need. I have used the small pencil butane torches right up to an oxy-acetylene torches with success. As I said it depends on the size of the parts that are going to be joined.

When Kozo did his series of engine builds he used a Sievers (sp?) torch that is hooked to a 20lb propane tank. His was used for 3/4" live steam locomotives.

Regards,
Bernd

 

[tmuir]

For small stuff I use my MAPP gas burner with disposable canister and larger stuff my propane burner, don't know what everyone else uses though.

 

[shred]

FWIW, my local Jeweler Supply store is quoting ~$25/oz on 'Easy' 1/32" silver solder wire this morning. I think 1oz is 20+ feet of wire.

 

[Mcgyver]

propane is easiest, using the 20lb cylinder as mentioned (so you don't constantly run out and have to buy those overpriced plumbers bottles) oxy acetylene is great for bigger assemblies; because of the heat it can deliver not the temp. O/A is too high a temp for SS and it can burn the flux, when you SS with O/A do so indirectly - keep the flame away from the joint and heat the parts

 

[tel]

What is the preferred heat source for working with silver solder. I have been using my oxy acetylene rig with a small torch tip, but it will just as happily melt my brass partsas it will the silver solder.Can I get away with using an ordinary propane torch instead?---Brian

Yo Brian, as others have said, mostly propane, but on the odd occasion where the o/a is needed the trick is to use a MEDIUM SIZED CUTTING TIP and use only the outer envelope of the flame, never the inner core. Using a small welding tip localises the heat too much and is a recipe for disaster.

 

[Stan]

Propane and butane have a high enough temperature for silver solder. The other consideration is volume of heat. For very small parts try one of the micro torches that use a throwaway lighter as the heat source. Lots of temperature but very little volume so it will only work on very small parts.

The Bernzomatic style torches that screw onto a 14 oz bottle come in many different orifice and burner sizes. A small burner will work on a lot of model work and if just a little short of adequate volume, any additional heat source (stove burner, second torch, barbecue) will get you by.

For bigger model work, a bigger burner on a 14 oz bottle or a hose type burner on a 20 lb bottle. A third alternative is the "plumber's torch" which is acetylene and air which will heat the biggest chunks you will silver solder.

 

[Kludge]

Propane and butane have a high enough temperature for silver solder.

Watchmakers & jewelers also use an alcohol lamp and blow pipe for soldering with easy, medium and hard silver and gold solder. The heated mass is small in these cases but it illustrates that modern techniques aren't the only option available. At the same time, some resistance soldering rigs can generate enough hot to do the trick as well. (Most can't so it's not a recommended method.)

I have a Smith mini-torch (currently Oxy-Acetylene but I'm shifting to Oxy-Propane in the interest of economy) and small hand held butane torch and a few butane "lighters with attitudes" that get just as hot (roughly 2500oF), and am looking at a small handheld propane-air torch from Micro-Mark (http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=83035) or something like it.

The Bernzomatic style torches that screw onto a 14 oz bottle come in many different orifice and burner sizes.

They do? Cool! Another thing to look for while at my local friendly welding supply house - or webinate for.

Best regards,

Kludge

 

[shred]

Garage and estate sales are a great place to get old Bernz-o-matic style propane torches in random sizes and shapes. Picked up a cigar box with two of 'em and a ton of lead solder for $2 the other day. At that price, you can experiment on them too.

 

[Bogstandard]

Oxy/acet should only be used as a last resort.

My personal view is that it should only be used on the higher melting point alloys, brass brazing or bronze welding and of course for normal welding.

A lot of people don't know that oxy/acet has in fact three modes of flame operation, carburising, neutral and oxygenating, and each one has its own use in types of metal joining.

Not having a perfect neutral flame will, not only have too much heat going into the joint, but the chemical composition of the joint could be altered, maybe for the worse.

Butane, propane or butane/propane mixes are ideal for what you will be doing.

I have been thru all this before in previous posts.

Three blowtorches will cover everything up to small boiler making. A pencil or 'cooks' blowtorch, a plumbers one that uses disposable canisters, and a large head torch running off a rechargeable tank. For most of the work done on here, a plumbers torch should really be the largest that is needed.

This is my motley collection, and have never needed anything hotter.

The popcorn bucket is in fact my portable quench tank.


John