Silver Solder For Brass Ornament

[brightspark]

I’m gonna braze it properly with brass rod and gas.

good luck on that one whats wrong with silver solder

 

[Brad93]

good luck on that one whats wrong with silver solder

The part has been repaired before and isn’t a tight enough fit for silver soldering

 

[Brad93]

tig braze?

No the zinc bubbles out too readily.

 

[Kram]

The part has been repaired before and isn’t a tight enough fit for silver soldering

Silverflo rods will be fine for that gap.

 

[Pigeon_Droppings2]

I was looking online....you can buy "brass filler" I think....basically brass powder that you can mix with epoxy to produce a filler. I've used glass filler with epoxy before with very good results....might be worth an experiment? With the glass filler it really changed the properties of the epoxy...it became more like car filler with a lot more body to it so a lot easier to work into shapes vs liquid epoxy.

So far looking like an excellent repair so I'm sure whatever you decide to do will look good.

 

[Brad93]

It’s a no to gas brazing it. No matter how hot I get it or how much I wire brush it and douse it in flux, the braze just rolls up into a ball and sits there or rolls off the part.

So we are onto silver soldering with HT flux or glueing.

 

[The_Yellow_Ardvark]

If the dowel and glue hiolds, it should.

Get some decent 2 pack epoxy glue, some bronze colour paint pigment and mix.

Then fill the crack and pits.
It will look like an age repair, if you get the colour right.

 

[Kram]

It’s a no to gas brazing it. No matter how hot I get it or how much I wire brush it and douse it in flux, the braze just rolls up into a ball and sits there or rolls off the part.

So we are onto silver soldering with HT flux or glueing.

Either wrong flux or too much localised heat? For the low temp silverflow you need 650c and easyflow flux, its active 550-750c (dull red). Above that itll turn black and wont stick. Silverflow will stick well before the part is red hot.

When I first tried silverflow I used sifbronze flux which is not active until 850c - that first attempt needed 900c, bright orange, to get it to stick, wasted much of a rod on that part, although it worked, I would have used a fraction of the gas with the correct flux.

 

[brightspark]

It’s a no to gas brazing it. No matter how hot I get it or how much I wire brush it and douse it in flux, the braze just rolls up into a ball and sits there or rolls off the part.

So we are onto silver soldering with HT flux or glueing.

hopefully it will be clean metal or it wont take it looked a bit rough when you saw the break as though it wasnt quality metal

 

[Brad93]

Back to this poxy statue. I’ve tried SIF rods and SIF flux, castolin 16 and castolin 18. It just does not stick. The filler just balls up on the surface. I’ve had it hot enough that the base metal starts to melt and the zinc starts to fume!

I’ve ground back to fresh base metal with a burr and everything. Last resort is TIG braze on AC. But the zinc is gonna fine like mad.

 

[Brad93]

We have beaten it!!!
It’s in the ultrasonic for 20 minutes now and then I will polish.

 

[Kram]

I’ve tried SIF rods and SIF flux, castolin 16 and castolin 18

They appear to be around 900c melting point, not the 650c of the high silver brazes?

 

[arther dailey]

excellent

 

[Brad93]

Finito. Not happy with it really. But it’s the best I can make of it.

 

[Seadog]

A blind man...

 

[julianf]

Finito. Not happy with it really. But it’s the best I can make of it.

View attachment 297201 View attachment 297202

Given the casting defects all over the job, i cant even see the repair in your photo, even though ive looked at the preceding photos, so i would say its perfect.

What method did you use for the final process in the end?

 

[123hotchef]

he pinned it!

 

[brightspark]

he pinned it!

he nailed it

 

[Brad93]

I drilled and reamed for 3mm dowels. The two halves were basically then a hammer together fit. But I was left with very slight misalignment and you could see the cracks.

I tried Castolin 16XFC with no joy. Just would not melt to the base metal. Then I ground with die grinder and tried 18xfc (nickel bronze 20°C lower melting temp), no joy. Basically had the base metal fuming but wouldn’t take. Tried bare brass wire with SIF flux. No joy.

In the end I decided I needed to melt the base metal so I tried TIG BRAZING on AC. Just poured zinc out and made a big mess. So I tried straight dc at 100A and just kept wire brushing the soot off. Luckily it was still really hot from trying to gas braze it.

Silicon Bronze TIG rod and fused the two together.

After it has cooled and I ground it with the die grinder, I gave it a quick buzz on a stiff polishing mop, then into the ultrasonic to remove the residual flux from brazing attempts, then more polishing. Then I used Loctite 290 on the pins to hopefully secure them in place forever and then used the 290 on any pinholes etc just to seal them up.

I didn’t even attempt to fuse the cracks still visable between the legs. I thought better a crack than a right mess.

The dowels had it. The welding was just to cover the cracks really.

 

[Brad93]

It was one of those jobs passed to me by a good mate for a friend of theirs. He asked how much I wanted for repairing it and I’ve actually told him nothing.

I don’t want any comeback from it if they’re not happy or it breaks next time it falls of the mantlepiece.

Really there’s probably 5 hours of attempting to repair that, pinning it, polishing it back up. These things really are never a viable repair. At our workshop rate that would have been over two hundred notes.