Brazing, what do i need

[peak4]

Macclesfield's nice, or what I saw of it on my only visit, but a bit far to buy one brazing rod.

 

Sorry, I really must learn to read properly or maybe drink more coffee.

I got it into my head that you wanted silver solder and the appropriate flux.

 

Expensive, but flux coated rods from B&Q

http://www.diy.com/search/results/?question=brazing+rod

 

or a call to most welding suppliers, but you might have to buy larger quantities.

If you're using plain brazing rods on steel, borax mixed into a paste for flux, likely available from a local chemist.

Boots certainly used to sell it.

[Nagel]

Sorry, I really must learn to read properly or maybe drink more coffee.

I got it into my head that you wanted silver solder and the appropriate flux.

 

Expensive, but flux coated rods from B&Q

http://www.diy.com/search/results/?question=brazing+rod

 

or a call to most welding suppliers, but you might have to buy larger quantities.

If you're using plain brazing rods on steel, borax mixed into a paste for flux, likely available from a local chemist.

Boots certainly used to sell it.

 

In fact I have some silver solder and I could try that for the job in hand, worth a try.

[peak4]

Good luck, if you struggle, let me know and i'll try and assist, though I don't claim to be an expert. (nor do i have any Oxy-Propane unfortunately)

[Nagel]

Nah, silver solder didn't work, it's brass and it needs soldering. I'm thinking that the Modelling/Model Railway shops might sell small quantities of brazing rods and flux.

[peak4]

I'm a little confused here, but then again I'm still on my first coffee.

 

Are you sure about your terminology? In rough order of melting points;

Soft Solder- Plumbers and Electrical 180-220C depending on the lead content (or absence)

Hard Solder- the various Silver Soldering alloys 600-800C

Brazing- Essentially using a brass alloy as the filler rod. 850C+

 

If the gizmo you're trying to mend/make is brass, then it's likely to have a melting point of about 900C.

Normal brazing rods have a melting point of somewhere around 850C, so you're in serious danger of melting the workpiece as well as the brazing rod.

 

See Here

Or Here

 

The second link are only at Dinnington, which isn't too far away

[Nagel]

I need to think about this. What kind of solder sticks to brass?

[peak4]

I need to think about this. What kind of solder sticks to brass?

 

Pretty much any, if you use the right flux and get the temperature correct. (though it doesn't stick to brass, it alloys with the outer surface of it.)

My first link earlier explains the process.

The flux removes the oxide layer, though it should be clean to start with, and prevents further oxide forming during the soldering process.

 

Heat the workpiece up, and use the heat from that workpiece to melt the solder. That way, the solder will flow correctly and not sit as molten solder balls on top of a workpiece that's too cool to allow the solder to flow into the joint.

 

In the ideal world, the joint should be mechanically secure before soldering. That way you should achieve maximum strength and durability.

 

What's the project?

Edited June 11, 2016 by peak4

[Janus]

Anyone know where I can get just one small brazing rod and some flux in Sheffield?

 

I have bought brazing rods from car spares shops years ago.

[cuttingedge]

Try welding supplies o Hollywell Rd

[Nagel]

Pretty much any, if you use the right flux and get the temperature correct. (though it doesn't stick to brass, it alloys with the outer surface of it.)

My first link earlier explains the process.

The flux removes the oxide layer, though it should be clean to start with, and prevents further oxide forming during the soldering process.

 

Heat the workpiece up, and use the heat from that workpiece to melt the solder. That way, the solder will flow correctly and not sit as molten solder balls on top of a workpiece that's too cool to allow the solder to flow into the joint.

 

In the ideal world, the joint should be mechanically secure before soldering. That way you should achieve maximum strength and durability.

 

What's the project?

 

It may just be that I'm not heating the parts hot enough before applying solder, or they're conducting the heat away. I only have a small Maplin gas soldering torch and the flame may be too small for the job, or I need to spend more time heating the parts.

 

I learned soldewring and brazing at school, but I've only ever used soldering skills for electrical wires to terminals since.

 

The project is obscure and hard to explain, but it's about restoring an antique x-ray tube. It involves re-attaching a rod (~1mm diameter) to a small thin plate maybe 15mm x 5mm