Welding Sil-bronze

Discussion in 'Castings, finishing/ repair/ and patina's' started by Jason, Jan 3, 2018.

  1. Jason

    Jason Gold

    Silicon bronze doesn't weld like steel. It doesn't weld like aluminium either. To say it welds like chewing gum is probably more accurate. It has a nasty habit of going from rock hard to a gooey mess quickly. Sadly there isn't much stuff on the net for welding cast bronze and I'm not sure why that is.... I've figured out it's easiest to weld on DC-EN with a 2% lanthanated tungsten or thoriated tungstens when using an inverter machine. I've tried green tungstens and grey tungstens and both produced erratic arcs that simply didn't work. As with any welding, heat control is critical and that means a careful touch with the foot pedal. Welding thick to thin is always a challenge and the normal dab technique is a farce with this. When you attempt to get the filler rod near the operation, it will ball up from the heat of the torch so you have to be quick to pull back the torch, get your dab on and get the heat back in there. The good thing about welding this stuff is it's really easy to grind it into shape due to it's softness. SO I needed a bronze pin that will allow a small piece of metal to swing to hold in a photo, piece of cardboard and a small sheet of glass. Here is the solution. Stacked bronze! The method is get a tiny puddle and dab. Allow a couple of seconds to cool, hit it again and repeat. The growing pin can be leaned by only heating on one side as necessary. If you use too much heat, the tower falls. The trick is to heat enough and control the depth of the puddle on the top of the pin. The oxy/acetylene guys should have learned this lesson years ago as the old farts would make students use bronze and braze up a little tree by stacking material. I essentially do the same process here to create the necessary pin. To lock the tab onto the pin, it's time to superheat the top of the pin and let it fall. Fun stuff, good exercise and can be practiced with just some bronze filler wire. Why do this? Simply because store bought trash from HD and lowes would look outta place on these little frames. ;) Now I get to fill in some of those tiny holes. It never ends.:oops:

    Stacked bronze
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    Shortened pin
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    Melted the top of the pin.
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    Last edited: Jan 3, 2018
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  2. Tobho Mott

    Tobho Mott Gold Banner Member

    I guess it's up to you to make the youtube video that shows us all how to weld bronze castings! :D

    Any reason you couldn't have built in that pin when you were working on the wax? Maybe you could leave a stub from one of your sprue/vents to grind down to size and shape.

    Anyhow, looks like building it up by welding turned out great - you gonna try and sell it, or is this one for keeping?

    Jeff
     
  3. Jason

    Jason Gold

    I totally could have used a piece of wax during casting and it would have made my pin in advance for me.. Trouble is, I wasn't that smart at the time. Learn from others, you wont live long enough to learn everything on your own.;)

    One of these is going up for sale. My wife claimed the other one. I'll toss the mold in the closet never to be seen again.
     
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  4. OCD

    OCD Silver

    And here I was thinking you were making another BP. :rolleyes:

    [​IMG]
     
    Last edited: Jan 4, 2018
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  5. LJLundgren

    LJLundgren Copper

    Is there a specific Tig rod you like you use? Or will any silicon bronze rod work? Are they all the same? I just bought an AHP 201X alpha. It’s in a box waiting for me when I get. Home. Never touched a tig welder before. I know about as much as a new born baby about it.
     
  6. Jason

    Jason Gold

    Good job man! That's a great machine for the money! I've been using airgas brand tig filler rod. It's been a good match when polished later. But I recently switched to raynor or something like that. It's just as good and much cheaper. Just be damn sure there is no ZN in the description on the tube.

    Buy 1/16" and 3/32" filler rod. Same for tungstens. Get both sizes. (either Lanthanated or thorium) This will be good for 95% of the stuff you will ever need to tig weld.
    Be sure to pickup steel tig filler wire while you are at it. If you want to try your hand at aluminum, get some 4043 filler wire. Same deal, 1/16" and 3/32"
    I learned on aluminum first.

    I posted somewhere a beginners lesson on learning to tig. Learn to make a puddle and stop. Then learn to make a puddle and drive it... Next, learn to make a spot, create a puddle and make one dab with filler and stop. Next, Make a puddle, take one dab of filler and move 1/8" make another dab and repeat. Tig takes PRACTICE PRACTICE PRACTICE!

    When you weld your bronze, unless you are sticking parts together, most times you will be just tig brazing holes and defects. What is tig brazing you ask? When "welding" you melt the parent material and with brazing, you only get it hot and flow the filler onto either the joint or the hole you are filling in.

    Gas bottle... 125CF, don't F around with anything smaller. BUY THE BOTTLE! and only fill with 100% argon. NO MIG MIX, no c25 despite what any shithead tells you. Set your gas CFM to around 15cfms as a good starting place. AND BUY A GAS LENS KIT!!! This makes your life sooo much easier! Here is your kit. https://www.usaweld.com/Deluxe-Stubby-Gas-Lens-Kit-p/sr17stglc-dx.htm
    You should be getting a 17 series sized torch. Call them and get a few spare 1/16" & 3/32" gas lenses and spare collets. You WILL F these up when learning. They are cheap bought individually. AVOID glass pyrex BS, you'll just break them and cook them etc...

    I'm not MR Tig.... I'm probably better than that fat shit at the end of the day, but I do this stuff regularly.. The guy to watch on YT is Jodi on welding tips and tricks and probably Justin on the fabrication series. Both offer solid Tig advice. Hope you get something useful from this info. I've made the mistakes and paid the price, but it's smooth sailing now for me.
     
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  7. LJLundgren

    LJLundgren Copper

    Wow! I really appreciate all that. I’m going to have to print that off and use it as reference. I’ve been watching the fabrication series videos on you tube. I just sent him a suggestion to do a video of welding bronze sculpture. Seems to be niche skill set. I’m looking forward to learning!
     
  8. Jason

    Jason Gold

    The gas lens allows you to stick out the tungsten much further. This will be a big help in the beginning as you will be struggling to see how close you are holding the tungsten and trying to keep the filler rod in the gas stream. Tig welding is kinda like patting your head, rubbing your belly, tapping your foot AND whistling Dixie all at the same time. Your foot is the gas pedal.
    I took on a big project to really get in and learn my skills at the beginning. https://www.handcraftedlanterns.com/steel-lanterns
    It was sink or swim that's for sure! If ya look close, you'll see I picked it up pretty fast.
     
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  9. Jason

    Jason Gold

    You don't need it. There is next to NO 100% bronze welding videos. I tried to get Jodi to do it. No interest and wont generate the views so why bother.
    Welding bronze is childs play compared to welding just steel or aluminum. Like I said, you get the metal hot and flow in the filler rod. Then you grind it back. That's tig brazing. It's super easy. Don't start with bronze. Make yourself weld steel or aluminum in the beginning or you will play hell later. I choose aluminum for the first month when I was learning. Remember, Chinese isn't hard for chinese babies, so try the hardest and everything else will be a cake walk.;)
     
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  10. Jason

    Jason Gold

    Correction on the names... Radnor is Airgas house brand. I've got Victory brand now and it's the same stuff. No difference from what I can tell. sorry.
     
  11. I like your work Jason. I learned that brazing and soldering don't melt the base metals being joined. When you are making a TIG joining in bronze with bronze rod you have to be melting the base metal to join, so it's welding. Correct me if I'm wrong. Are you indeed not melting the surface of the base metal to get the joint?
     
  12. Jason

    Jason Gold

    You are right. If you melt the parent material, its welding. With bronze, most of the time it's not necessary to melt the base metal. It comes down to the tensile strength difference between a weld and a bronze brazed joint. Surprisingly, bronze brazing is extremely strong by the numbers. Seeing our artsy fartsy stuff is seldom structural, a brazed connection is usually just as good as a weld. I will however melt the base bronze if I think it will carry some weight to get a better foothold. Example would be the bronze porch light I did. That sucker is 7lbs and it hangs on 2 3/4" pegs. Those I went after some good penetration.

    20190719_141021.jpg
     
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  13. dennis

    dennis Silver

    Some further additions:

    1) if you encounter unknown stainless steel (e.g. storebought cookware, or Clackamas Steel's stainless area,) you will desire E309.

    1b) for furniture-grade welds on, say, 16 gauge steel tube, where a "smooth and lovely appearance" is a trifle more important than maximum strength - E309. This is so much the case that I secured some in .045, in addition to the former 1/16!

    2) you may wish to secure a dedicated grinder for putting the point to your tungstens. I like to use diamond lapidary disks, purchased through Amazon. I still dip mine (tungstens) a fair bit - and when you foul your tungsten - stop and clean the "stuff" off. Also, keep a sharp, 20-30 degree point on your tungsten. (DC) A.C. supposedly will round them over.
     
  14. Jason

    Jason Gold

    I saw some dude the other day the tube make a jig thingy for his cheapy angle grinder that was spinning a diamond disc. I'm guilty of using the bench grinder and getting back to work. I know not the best practices.:oops: I really should do something more respectable for sharpening tungstens, but 300clams and up for a proper tungsten sharpener is straight up bat shit. I'm kinda surprised the chinese haven't come out with a $49.95 special.
     
  15. dennis

    dennis Silver

    Uh, they have - sort of.

    I bought an H-F (Harrob Frigate) grinder, in the 5 inch size, and bought 5 inch lapidary disks from Amazon. One was - I think - 80 grit, and the other, 400. I've been using a 4 inch disk, in 320 grit, mounted against the side of the wobbly grindstone, and that works "passably." I get my point on well enough.

    I want to get metal 5 inch disks to replace the wobbly grindstones, but ye Virus hath put the Kyebösh on Foundry for the time being, mumble, mumble.
     
  16. Jason

    Jason Gold

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  17. dennis

    dennis Silver

    Oh, my. Yes, nice spendy piece. (It took a significant chunk of a year to save for the 201.)

    Traded in my flat "80" for a torpedo a couple of months ago. Now have 150+ cubic foot of Argon. Getting it up the stairs was trouble...
     
  18. dennis

    dennis Silver

    harbor-freight-salvage-co-73741811.jpg the boat supplies the frigate part. Harrob is an anagram for "harbor" - I think.
     
  19. Jason

    Jason Gold

    The Hazard Fart works for me. I know how saving goes... When I bought my invertig, the wife was NOT HAPPY!
     
  20. dennis

    dennis Silver

    I am not surprised overmuch. (About Madame's displeasure.)

    In my case, I simply do not have much to work with in terms of funds, and getting more is not easy at all. (Congenital disabilities, disfigurement I was born with, advancing age, and chronic illness is mostly why.)
     

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