How to weld bronze cast

[BOBBYLEE]

I've got at peice of bronze cast that needs to be welded. I tried DC Tig but the weld was very trashy and it cracked in the center of the weld. I used silicone bronze filler. What's the correct procedure to use. I have a Dynasty 210 DX. Any help is greatly appreciated.

[H80N]

I've got at peice of bronze cast that needs to be welded. I tried DC Tig but the weld was very trashy and it cracked in the center of the weld. I used silicone bronze filler. What's the correct procedure to use. I have a Dynasty 210 DX. Any help is greatly appreciated.

Many times Bronze sculpture castings are TIG welded using AC HF like for aluminum because it it tends to jiggle the puddle and loosen the impurities

Could you post some pics pls...??

are you sure it is bronze and not brass...??

[ryanjones2150]

I actually have a friend that works as an assistant for an artist that works in bronze castings. I haven't posed your question to him yet, but I know they use a MIG welder with silicon bronze wire for cracks and to fill imperfections in their castings, then grind them down. <br />
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But I completely agree with H80N on the AC polarity. I would also suggest aluminum bronze vs the silicon bronze. Mostly because I've used it more on AC than on DC or silicon bronze on either setting. I think you will find the aluminum bronze nice to work with on AC. <br />
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But pictures would really be nice to help make the proper recommendation. Also, this would be tig brazing and not welding. Of course you'll melt the base metal a little bit from time to time, but try to melt as little as possible. I generally expect a little base metal melting at the start, but after that, you should be able to control it pretty well. Also be sure to taper off slowly to avoid those crater cracks at the end of the weld, especially with aluminum bronze.

[BOBBYLEE]

How do i post picture's? Can't get a pic till tomorrow b/c the piece is at work. I'll try the AC and see how that does. How do I know its not brass?.. Well, I really don't but it doesn't look like it. One of the guys there said it's bronze cast....

[H80N]

How do i post picture's? Can't get a pic till tomorrow b/c the piece is at work. I'll try the AC and see how that does. How do I know its not brass?.. Well, I really don't but it doesn't look like it. One of the guys there said it's bronze cast....

The division between brasses & bronzes is kinda murky... but generally brasses have a high zinc content... and will boil off white smoke while welding

is it an art casting..?? or marine hardware..?? or..?? tell us more

[ryanjones2150]

You don't want breath the fumes of the zinc boiling out either. Another reason when brazing is a good plan. <br />
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As I've been told, there is very little that separates bronze and brass metallurgically. I don't fully understand it. I don't think it really matters in your case. <br />
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Depending on how big your repair is, soldering might be an option. <br />
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I sent a message to my friend with experience in that area, I'll report back what he suggests. Although he'll almost certainly want more information on the piece. <br />
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To post a picture, are you using the phone app or a computer? Super easy with the app, just tap the "add" button on your post and select photo from library or camera.

[BOBBYLEE]

The piece is off an old barber chair, foot rest I believe.
What app do I own load? As of now I just go to Miller's site and log in from there. I didn't know there was an app. Thanks for everyone help.

[ryanjones2150]

I use the miller forum app. I'm sure if you search the App Store for whatever phone you have you can find it. <br />
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A bronze barber chair eh? I have absolute zero experience with antique barber chairs, but bronze? That's pretty cool I suppose. <br />
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I'll pass that along to my friend and see what he says. His experience is strictly with bronze casting for fancy schmancy statues.

[BOBBYLEE]

Here's some pics.

[BOBBYLEE]

Here's a pic

[H80N]

Here's a pic

Looks kinda like cast IRON..........

have you put a MAGNET to it...???

[ryanjones2150]

I agree, it doesn't look at all like bronze.

[griff01]

Here's a pic

I agree with H80N & ryanjones, that's not bronze.

Griff

[H80N]

I agree with H80N & ryanjones, that's not bronze.

Griff

Once we figure out if it is Bronze... Iron... Or....??

The crack joint will have to be properly veed out and prepped... BEFORE welding

As pictured.. it is UNPREPARED...
any welds attempted in this state..are likely to fail in short order...

[ryanjones2150]

Yo, Bobbylee, so what does that part do? Is it load bearing or just decoration? How thick is it? Have pictures from other angles or maybe further away to give us an idea on what it is? <br />
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Ideally, you'll have a full penetration weld, which will make that piece one solid piece of metal again. Depending on how thick it is or what it does, that may not be possible nor necessary.