silver soldering steel to steel

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Carrdo
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Joined: Thu Mar 06, 2003 2:20 pm
Location: Toronto, Canada

Re: silver soldering steel to steel

Post by Carrdo »

Mostly, It is all about the lead content of the steel - peroid. The higher it is, the more difficult it is to silver solder. Not impossible, but much more difficult particulary if the lead content is > 2%. Mild (low carbon) free machining steel has a lot of lead (6-8%), as do many cold rolled steels, so I do not try to silver solder with them. Structural (hot rolled steel, lead free) is easy to silver solder once the basics are learned.
RET
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Location: Toronto, Canada

Re: silver soldering steel to steel

Post by RET »

Hi,

One thing I forgot to mention is that I do all my silver soldering on an insulating brick "hearth." This makes a big difference, since you don't have to worry about the heat getting away from the underside of the part. Don't use firebrick, it isn't a good enough insulator; what you need is the white insulating brick. Mechanically, it has no strength, but it is a very good insulator. It gets white hot almost as soon as you put the torch on it, but take the torch away and you can put your hand on the heated surface a minute later.

I find that with oxy/acetylene, it is too easy to overheat the joint so I always use propane/air, I just choose the size of the tip to suit the job. I also still have a supply of cadmium silver solder; I haven't tried the new stuff yet. Its amazing how long a coil of wire lasts because you only use a little bit at a time. Don is posting from sunny Spain, he's missed the one foot of snow we got Monday night.

Hope this helps.

Richard Trounce
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Fender
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Location: Chattanooga TN

Re: silver soldering steel to steel

Post by Fender »

Carrdo wrote: Wed Jan 30, 2019 5:33 am Mostly, It is all about the lead content of the steel...snip.....Structural (hot rolled steel, lead free) is easy to silver solder once the basics are learned.
An excellent point. I rarely use anything besides hot-rolled steel (or sometimes stainless) for a silver-brazed assembly.
Dan Watson
Chattanooga, TN
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BAdams
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Joined: Wed Feb 23, 2011 7:15 pm
Location: Moreno Valley, CA

Re: silver soldering steel to steel

Post by BAdams »

For small stuff you need to heat from below:
Soldering Tripod
Soldering Tripod
Rio Grande, lists their's as 9"-high (229mm) steel tripod with 4-3/4"-diameter (121mm) ring and a 6" square screen.
https://www.riogrande.com/product/solde ... ens/502085


Brook
JohnHudak
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Location: Ohio

Re: silver soldering steel to steel

Post by JohnHudak »

Carrdo wrote: Wed Jan 30, 2019 5:33 am Mostly, It is all about the lead content of the steel - peroid. The higher it is, the more difficult it is to silver solder.
This was what I was afraid of... I'm not sure if it's doable. I'd hate to invest a ton of time in several pieces, then find out that I can't solder them together..
John Hasler
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Re: silver soldering steel to steel

Post by John Hasler »

JohnHudak
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Location: Ohio

Re: silver soldering steel to steel

Post by JohnHudak »

Interesting, I always thought 1018 had some lead in it, thanks for posting that..
John
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Bill Shields
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Re: silver soldering steel to steel

Post by Bill Shields »

perhaps you are thinking of 12L14 or similar, which is full of lead....
Too many things going on to bother listing them.
RET
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Location: Toronto, Canada

Re: silver soldering steel to steel

Post by RET »

Hi John,

The obvious question is; why not take a couple of pieces of the steel you are going to use and try to silver solder them together? This should give you all the answers you need before you put any significant work in what you want to make.

From what Don & the others are saying it should work just fine. The only material I have ever had any difficulty with is cast iron.

As they say, "Try it, you'll like it!"

Richard Trounce.
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gamh44
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Location: Australia

Re: silver soldering steel to steel

Post by gamh44 »

RET wrote: Sat Feb 02, 2019 10:32 am The obvious question is; why not take a couple of pieces of the steel you are going to use and try to silver solder them together? This should give you all the answers you need before you put any significant work in what you want to make.
Good advice! I have just done this with the N&W tender bogie frames. I used the practice pieces that are from the same stock as the real ones and the same size. This is my first time silver soldering steel and I didn't expect it to go as well as it did. Clean joint. Flux and clamp. Heat with O/A and apply the solder, which flowed very nicely following the heat.

Here is the result:
53. FrameSS1.JPG
Hard to see in the photo but the fillet is nice and small which it what I was hoping for.
piedmontg
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Location: Hills of Illinois

Re: silver soldering steel to steel

Post by piedmontg »

Hi
I was reading this over as I am about to silver braze a steel two throw crank, ie 4 webs, for a model engine.
The webs are hot rolled and the shaft and throw rod are drill rod. I did an experiment run using Harris black and some
non cad braze. Came out fine but I have two questions

In the past I used to use Sparax 1 for pickling steel but have searched around and not found any locally, so I am going to use Muratic acid 32% diluted to 15% - 18%. Is that a good reduction?

Second my setup uses firebrick and I was looking for the "insulating brick" mentioned above. I keep getting back a ceramic brick material. Is that what I need to get?

Thanks

Bob
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Builder01
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Location: Erie, PA

Re: silver soldering steel to steel

Post by Builder01 »

Insulating fire bricks are available on Ebay. Here's the type I got:

https://www.ebay.com/itm/K-26-Insulatin ... :rk:1:pf:0

These are not exactly cheap, but, they are the correct type and work well. I used them with a Sievert propane torch to completely build a copper boiler for a 1" scale locomotive. The barrel is 5" in diameter by 19" long.
IMG_20161107_172207 - reduced.jpg
For pickling, I use food grade citric acid. (get it from Walmart) Works great and is completely safe.

David
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