Brazing brass to brass advice needed

[restorer]

I'm going to look at job next week and by the sound of it will need something a lot stronger than solder to repair.

From what I've been told its a sort of cast filigree (pierced) design chandelier arm that has snapped off at about four or five points. Because of the length of the arm it will need a good firm joint to bear its own weight. I'm thinking brazing, but what rod is best for this type thing? I've done this sort of thing in steel but am worried the high temp needed for brazing might just blow it to bits if I'm not careful.

I'll see if I can get a decent photo with my phone when I go to see it to give a better idea, but I want to go armed with enough knowledge to decide whether to turn it down there and then if it's going to be too hard.

Ta.

 

[Chris Stevens]

Brazing isnt ideal for this type of job due to the fact that melt temp of the filler might be higher than the material you are trying to repair. Silver solder is the thing to use here, and should work fine.

 

[restorer]

Thanks, that's just what I needed to know. I have a plumbers brazing/soldering torch and a mini oxy kit. Which do you think I'll need to use for silver soldering?

 

[brightspark]

Thanks, that's just what I needed to know. I have a plumbers brazing/soldering torch and a mini oxy kit. Which do you think I'll need to use for silver soldering?

use the mini oxy kit u will have more control over the flame [ localise the aeria heated

 

[runnach]

Thanks, that's just what I needed to know. I have a plumbers brazing/soldering torch and a mini oxy kit. Which do you think I'll need to use for silver soldering?

You,ll do a far better job if you can lay your hands on normal O&A set, mini set may ot cut the grass? Silver solder all the way for a decent long lasting repair!

 

[chunkolini]

I have done repairs on brass using O/A and brass filler rod.
A bit nerve wracking, but in effect you are fusion welding it, not brazing the join.
I would reccomend getting hold of some bits of brass and practising, you can get an almost invisible join but you have to watch out for the parent metal melting back, use smaller brazing rods the they start to melt first so you know you are near the melting point of the workpiece.

A cast chandelier, that sound like fairly beefy stuff, should be ok like this. You can watch out for it coming to a red heat, just remember that it will take a lot of heating as it will absorb a lot of heat being copper based. Also when you pick it up after doing the job the heat will have travelled a long way round the structure.

Good luck

 

[the artfull-codger]

I would be very wary of doing this job,as stated above silver brazing is probably the best bet but make sure it's cast brass & not aluminium alloy''brassed'' over the top,also these things tend to be of a crystaline nature & easily melted, good luck.


slan go fol

 

[brightspark]

I would be very wary of doing this job,as stated above silver brazing is probably the best bet but make sure it's cast brass & not aluminium alloy''brassed'' over the top,also these things tend to be of a crystaline nature & easily melted, good luck.


slan go fol

was thinkin that myself mine at home are made of the same crap they break easily where as cast solid brass wouldnt

 

[Tigman]

nice to know Im not the only one who gets these horrible jobs have been caught out a few times when you think its brass and it aint ! , Lets be careful out there !

 

[runnach]

Leave it outside over nigh, if still there in the morning, will be some chap lloy crap, if gone, pikeys will have yer brass

 

[the artfull-codger]

ha ha nice one runnach, the theiving ''scrap men'' cleaned me out of £1600 s worth of gear here, a couple of weeks ago, the worst thing is they probably only got about £20 for it,Tony Martin had the best Idea.

slan go fol
.

 

[jugs]

Silver Solder, use Oxy A, Pickel before & after with CITRIC ACID

best materials from > (not cheepest but best + good tech backup)


Johnson Matthey
Metal Joining York Way, Royston, Hertfordshire, SG8 5HJ, UK
Telephone: +44 (0) 1763 253200 Fax: +44 (0) 1763 253168 email: mj@matthey.com
www.jm-metaljoining.com

http://www.jm-metaljoining.com/

If its an Ali aloy, same process diferent materials,

or you could use gaffer tape

 

[restorer]

Thanks for the replies. I may turn this one down as I've discovered it's also ormolu, which means it'll burn off about two to three inches of gold either side of the joints which will mean more work re gold plating that.

It'll be Wednesday when I actually get to see the thing and can make a decision. If he begs me to have a go I'll charge for the proper job and give him low expectations on what can be done. I have successfully lead/tin soldered these type of thngs in the past but don't think I'll get away with that on this one. The arm is a 3 feet long casting and will just break off under it's own weight without a good solid weld as the break is near the inner end.

 

[restorer]

Just to update you all on this.

I cheated in the end. The arm was beyond repair because the break was twisted and too fine (it was thin tube section) to rejoin. Anyway, job done and it's been sold.

As the thing had ten arms (it was huowge, nearly seven feet across) I simply removed them, tapped and filled the holes in the centre mounting plate with treaded rod. Welded them in place then re-drilled new holes spaced for nine arms, then gold plated over the repairs. It has been sent to the buyer and they never even noticed one had gone from when they first saw it in the shop.

I made my customer (an antique dealer) remove all the glass drops and swags and put them back after. It took him two days both times.

 

[colin w]

Small brazing job -any volunteers?

Hi
I am looking for someone to do a small job to attach a brass badge (2.5"x2")to a brass buckle (3.5"x3").
You can see from the photos that it would be possible to attach a couple of screw head posts to bolt the two together (there are already a couple of holes drilled in the back plate).
Could you tell me if this is the sort of job you can do and what the cost would be.
I am based in the West Midlands UK - so I can post it or drop it around.
Thanks in advance
Colin

 

[brightspark]

Hi
I am looking for someone to do a small job to attach a brass badge (2.5"x2")to a brass buckle (3.5"x3").
You can see from the photos that it would be possible to attach a couple of screw head posts to bolt the two together (there are already a couple of holes drilled in the back plate).
Could you tell me if this is the sort of job you can do and what the cost would be.
I am based in the West Midlands UK - so I can post it or drop it around.
Thanks in advance
Colin

it would need silver soldering. brazing would melt it

 

[pedrobedro]

Ordinary solder would be plenty strong for that. If you have a blow lamp it would be a ten minute job. Fetch the pips off the back of the badge so it is flat and clean both pieces up with wire wool, flux it and heat it up from behind then just touch the solder on the join and it will run in nicely when it's hot enough. Leave it to cool then polish it.