Gold solder for brass

[Richard Braithwaite]

Has anyone tried 9 carrat gold solder for brass? I guess it might give a better colour match?

If so how does it age? (I.e colour of solder as surrounding brass oxidises and darkens)

[Snug Harbor Johnny]

... sounds like expensive solder.

[Richard Braithwaite]

Yes (about £10/5cm length) but only small quantities would be needed...

Edited Thursday at 12:47 PM by Richard Braithwaite

[BANYAN]

An interesting question Richard; I too would be interested in knowing.  Perhaps a question to jewelry supplier?

 

cheers

 

Pat

[paul ron]

how about brazing brass using brass rods?

 

for brazing small parts, you dont need a torch. i use a mini butane torch. the brass rod comes in all gages, even wire form. flux is important.

 

here is a nice article how to braze...

https://weldingproperty.com/how-to-braze-brass/

 

 

Edited yesterday at 03:51 AM by paul ron

[Snug Harbor Johnny]

One other thing ...  Gold - even 8 carat gold (the kind used in jewelry for people who want to show a lot of "bling", yet get the most bang for their buck) - won't change color much over time, at least nowhere near the amount of change brass will get a brown patina.  This means that the solder point might become more and more noticeable over time unless completely painted over.  I'm making a few brass fittings for a special project now, and do everything possible to saw cut, drill, file, bend, twist, lethe turn ... and any combination of the above to make each piece needed either without soldering or with a press fit.

[druxey]

Would electroplating the fixtures be a better solution?

[oakheart]

On 6/12/2025 at 11:41 AM, Richard Braithwaite said:

solder for brass

There is a brass ( sort of ) coloured silver solder in UK

I can't remember where I got it so you will have to google for it

Tim

 

[tmj]

This stuff isn't very expensive at all and 150 pieces 2mm X 2mm will solder a LOT of parts, however! Bear in mind that no matter 'what' alloy of solder you choose... color matching is always going to be a problem... at least for us hobbyists who rarely know the exact numbers of the alloys that our parts are truly made of. We just buy stuff generically called brass, copper, etc. The true makeup of that material is usually a mystery. 

 

2 * 2 mm 150 Pcs Gold Solder Silver Solder For Jewelry 14K Gold Solder Including E Solder M Solder H Solder Easy Welding for DIY Jewelry Making Repair Electronic Soldering 1 Gram - Amazon.com

Edited 17 hours ago by tmj

[Dr PR]

tmj is right about the solder stain on brass. Solder dissolves into the brass, so no amount of polishing can eliminate the solder color.

 

I was curious how the people who make brass model train engines and cars manage to solder everything together without any visible solder stain. They use resistance soldering mostly for anything that will be visible after the model is finished. Very small (1 mm x 1 mm or smaller) bits of solder foil are sandwiched between the parts and the electrodes are connected/placed on the two parts. A quick zap of current through the pieces melts the solder and it flows into the joint but no where else. Maybe a tiny solder fillet is visible at the junction with a magnifier but otherwise no solder is visible.

 

You can make your own solder foil by hammering ordinary round solder flat.

 

It takes a lot of planning to make the brass parts fit tightly before soldering, but the results are beautiful.

 

I have done something similar with an ordinary soldering iron where one side of the joint will be hidden inside the model. I just lightly tin each side of the joint to be soldered and then put the two pieces together and heat them until the solder melts.

 

Sometimes I just clamp the two pieces together and brush some liquid citric acid based flux into the joint (I prefer this flux because it smells like oranges). Then I place some small diameter solder against the inside or hidden side of the joint and heat it with a soldering iron. The solder flows into the joint where the flux is but no further, with none visible on the outside or visible joint seam. But this can leave some solder stain on the inside where the soldering iron touched the brass.

Edited 10 hours ago by Dr PR