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Trouble with tig welding small Everdur bronze piece to larger bronze.
kaumlauf -
Thursday, September 3, 2009 - 8:17pm
bronze | setting | thickness | TIG | welding Hi, I am an inexperienced tig welder trying to weld a small ear to a larger horse body- the body is about 12" high, and pretty thick- close to 1/4" thick walls.(cast). The ear is about 1/4 x 1/2". The ear just melts into a blob, and the stub on the main body just plops. I have it set to the lowest temp, but am still getting way too much heat. Tried using oxy/acetelyne too, but am havin tropuble getting the larger piece up to temp, as the small piece gets red hot much sooner. Is this basically a waiting game? Wait about 5 minutes or more for the bronze to heat up? I have been holding the oxy/acet torch on the body for nearly 5 whole minutes, and it still isn't puddling. Anybody able to help me? Much obliged- Katty  Trouble with tig welding small Everdur bronze piece to larger br
johndach -
Saturday, September 5, 2009 - 11:53am
Yes, welding a small piece to a large piece of bronze does present problems...... Have the small piece ready, get the large piece hot then get the small piece near to weld. Also what size Tig tip are you using? Might look at how well the Tig tip is ground (good, clean taper with a sharp point and the sanding marks going in parallel with the Tig rod, NOT around it (makes for VERY poor arc and other problems). Be sure you are using the correct electrode alloy (thorated). Be sure the machine is correctly set up for bronze. Set the temperature control to the heat that you would use on the heavy head part but no more. If possible, use a heat sink holder on the ear, away from the area you are welding to (try) to keep the ear from melting via some sort of heat sink (big locking tweezers, forceps or some such) attached away from the area to be welded. Apply the heat to the heavy part, not the ear, when actually making the weld, using the metal conductivity to heat the ear. It should actually be a VERY FAST weld operation. Practice using some pieces similar in sizes (the head and the ear) to get the process/timing/heat down pat. Once you figure it out it is pretty amazing what you can do and how fast it actually goes. I don't know where you are (I am in Sequim WA NW part of the state) but if you have a welder friend who could show you this sort of thing, you will see how it actually does work. I amazed me the first time I did it (on a $12,000 bronze sculpture). One last thing is using a low temp silver solder. Problem is the line of silver solder will show and will NOT patina like the rest of the bronze. I will say, that on this sort of work situation, some practice with scrap will REALLY help and give you confidence. Good welding.......... John Dach PS if you are close to us, please feel free to contact me and come on over for help/demo etc.  welding tiny bit to large piece
kaumlauf -
Tuesday, September 29, 2009 - 1:33pm
Thank you for all that help. I've been away- am just getting back- Thank you!
kaumlauf -
Tuesday, September 29, 2009 - 1:40pm
I'll give a big start and ease back, and I'll keep practising-I think it's an art- the more you do it, the better you get- horse ear
visitor -
Saturday, September 5, 2009 - 10:54am
Rich Waugh's advice is very good. If you remain frustrated and want to reattempt using your torch you'll want to preheat the main body. The piece should be welded or brazed in a heat refractory environment; ie. pumice or heat brick arranged into a shallow bowl setting. The best would be to use a high temp hot plate and heat the piece to about 800F but I think you could get by with heating for 30-45 mins in your oven at the highest heat and then straight away to the torch.While the piece is heating in the oven raise the temp in the welding area with your torch as much as you can. Good luck. Dan Culver Have you had no success
visitor -
Thursday, September 10, 2009 - 12:21am
Have you had no success brazing the ear to the head using your silicon Bronze rod ? Normally you would have to have an immense amount of amperage in order to do the job properly. Much like copper, you have to get a 'sharp pointed arc' and work on one side at a time moving the puddle from the head into the ear and then off again / on again. Using a pulse setting might help if your TIG has that option... The other thing you can do is pilot one or two small 1/16" (slightly reamed) holes in the head where the ear should be, then the same size hole in the bottom of the ear itself. Then simply cut a 1/16" piece of silicon bronze brazing rod (slightly tapered on both ends) and fit both pieces together. With a bit of clipping, you should be able to get the Ear to sit slightly off the head, leaving a small gap. Use lots of flux under the ear and heat the surrounding area until the gap starts to close. Once closed, heat the upper portion of the ear to cherry red and remove the heat. Do the same with both sides of the ear and it should have sealed quite nicely. If all else fails, drill it, tap it, screw it and braze it with your TIG, using Silicon Bronze. Still no LUCK ? There is a FINAL option that WILL work no matter what... Tin both the ear and the stub with 'CopperPhos 0' (as in 'zero', not containing any Silver) and then with a soft neutral flame, braze the two together.... No flux needed and the color match will be FAR better than Silver Solder and will also take a Patina.... Just my .02 Cheers, /Jman... ear to head welding
kaumlauf -
Tuesday, September 29, 2009 - 1:38pm
Thank you for the answers and insights. I ended up using oxyacetylene with a very small tip (00)and welded on too much bronze, then sculpted an ear into the mass, using burrs. I did this at least 6 times tll i got it right. I am learning how to sculpt directly in bronze! Am having other issues with my Giantech Inverter machine from China, but it does crank out the power, so will work with it 'til i can afford a nice big Lincoln! Miggin' bronze
visitor -
Wednesday, January 6, 2010 - 8:42am
If nothing works that others have suggested or you have already succeeded, great. If not then why don't you braze the darn thing and have done with it! |
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ArtMetal
Katty, When TIG welding
Katty,
When TIG welding silicon bronze (Everdur), or other highly conductive alloys, you need to apply high current at the start and then back off the second you see a puddle form. It takes a lot of amps to overcome the conductivity of the bronze, but once you have, it is easy to melt the whole thing into a puddle if you don't back off the heat some.
I generally start out by jumping on the pedal of the TIG welder - all the way to the stop, while very closely watching the arc. The instant I see melting, I ease back on the pedal to just enough heat to keep a small puddle melted but no more. After the puddle is stable I introduce the tip of the filler rod into the arc just above the puddle and allow it to melt and flow into the puddle.
If you try to go easy at the start, you'll get too much of the piece up near the melting point and then when you try to heat a bit more the whole thing collapses. I realize the "hit it hard and then back off" method is somewhat counter-intuitive, but it the right way to weld copper alloys.
Good luck with it!
Rich