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Anyone have any thoughts on machine settings for this repair? AC? DC? Preheat? Amps? Its a big hunk of cast iron. I need to find some cast iron to test settings on. If this repair doesnt work, could be $600+ to get another valve. ☹️ Someone didnt maintain their farm tractor hydraulic fluid. Got water in it and probably froze. I am going to TIG braze this with silicon bronze.Thanks.
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Millermatic 211Lincoln Precision TIG 225Century 250 MIGLincoln 225 AC Box (sold)I support my local welding store (Amazon, McMasterCarr, Cyberweld, EBay).
Reply:If you're going to run silicon bronze I would preheat the part to about 200°F . I prefer AC. I would set the machine to somewhere around 200 Amps then use the pedal to get the proper flow of the silicon bronze.
Reply:It looks to me like the crack goes all or most of the way around the threaded area, and that it's a clean break. I assume that part is under hydraulic pressure, so needs to be bonded the full depth of the crack. Assuming I could remove all the embedded oil, I might consider silver solder in order to get that full depth of penetration at a lower temperature, and would prefer a gas torch to better control the heat. With TIG, overheating the surface in order to properly heat the greater material mass around it seems too easy. I also like using nickel silver if the higher temperatures aren't a problem.
Reply:You may want to consider a special rod given the circumstances (could be $600+ to get another valve) and run on a scrap piece before making the repair.HERE is what I am thinking for a TIG rodOr call this company and speak to a technician, I have always gotten good advice from themI have used sil bronze to (TIG weld) repair cast, but it was a handle on a lathe, so nothing critical but it is still in use.RichardWest coast of Florida
Reply:You could use cast iron rod. About used tig on cast iron it was using cast iron rod so matched the iron. Brazing I like using a torch as I could control the heat better. Dave
Originally Posted by Fab54
Anyone have any thoughts on machine settings for this repair? AC? DC? Preheat? Amps? Its a big hunk of cast iron. I need to find some cast iron to test settings on. If this repair doesnt work, could be $600+ to get another valve. ☹️ Someone didnt maintain their farm tractor hydraulic fluid. Got water in it and probably froze. I am going to TIG braze this with silicon bronze.Thanks.
Reply:I would consider boring out a cylinder of the threaded part and silver soldering in a threaded bung (if replacement is too expensive or out of the question).
Reply:
Originally Posted by Weld_
If you're going to run silicon bronze I would preheat the part to about 200°F . I prefer AC. I would set the machine to somewhere around 200 Amps then use the pedal to get the proper flow of the silicon bronze.
Reply:
Originally Posted by Fab54
Ok this is incredibly difficult. I did silicon bronze on a jeep door once. There is a braze between the sheet metal skin and the window pillar and support and it came out nice. I practiced on a piece of cast from home depot and then a piece of steel. Can't get any shiny yellowish color. Tried AC, DC-, DC+ nothing. Ugh.
Reply:
Originally Posted by Fab54
Ok this is incredibly difficult. I did silicon bronze on a jeep door once. There is a braze between the sheet metal skin and the window pillar and support and it came out nice. I practiced on a piece of cast from home depot and then a piece of steel. Can't get any shiny yellowish color. Tried AC, DC-, DC+ nothing. Ugh.
Reply:
Originally Posted by Fab54
Ok this is incredibly difficult. I did silicon bronze on a jeep door once. There is a braze between the sheet metal skin and the window pillar and support and it came out nice. I practiced on a piece of cast from home depot and then a piece of steel. Can't get any shiny yellowish color. Tried AC, DC-, DC+ nothing. Ugh.
Reply:Something I do not understand about tig welding silicon bronze is how to take advantage of the capillary action. I see it working on sheet metal. But on heavier sections with only a tig torch, I see running beads, but hanging out til it flows between the joint is difficult since the bronze is a heat sink.Ion kno. Seems like a o/a torch job if the crack need to be filled inside?
Reply:
Originally Posted by Weld_
If you think silicon bronze is difficult wait till you try aluminum bronze.
Reply:
Originally Posted by Oldiron2
Which is why I made the suggestions I did in Post 2. With both Silicon- and Aluminum-bronze, the first metal is quite reactive, forming refractory oxides easily with any contact to the air. Unlike copper oxide, which is slightly soluble in copper, these oxides aren't soluble and form a thin refractory barrier on the surface, one not easily attacked by flux. In an evacuated or Argon-filled induction chamber, both might work admirably, and with a gas flame in the hands of one who could maintain a non-oxidizing area around the break at all times, both might be fine.A break in cast iron like that has lots of rough surface, with the parts typically fitting together very closely. Applying just a thin bit of flux to the cracks or on all open surfaces, then joining/holding together the parts and heating evenly with a gas flame allows a good silver solder or the right bronze alloy to wick into the cracks, they meanwhile being protected by the flux and the thin spacing plus the covering gasses from the flame. The joint can be at least as strong as the original cast iron. If the original material was heat treated such as to become malleable, silver solder won't exceed the critical temperature, thereby not causing other problems..
Reply:It would be much appreciated if somebody(a user) would do a thread on a silicon bronze and silicon aluminum.
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Originally Posted by Weld_
I am not sure if silver solder would work in this particular situation (not that it can't but it's tough to judge that from one picture). The OP wanted to know how to approach the settings with silicon bronze so I gave my opinion on that.I think the reason that so many people struggle with silicon bronze, aluminum bronze, silver solder, etc. is because they just don't do enough of it. It's a skill set like anything else, and it's different from welding to an extent. If all you do is weld and rarely utilize brazing or soldering you're going to be just one step above a beginner IMHO. Couple that with the fact that most people just want to jump into their project or problem, which oftentimes is more complicated than practice coupons they end up with results that are less satisfactory to them.
Reply:
Originally Posted by tapwelder
Probably too hot, melting base metal. I have not figured out tig brazing’s function. Many folk use it in an decorative, as opposed to structural. Think heat, not weld. If grayish then there is base metal in the bead I would use silver or bronze and a torch. At least you can flow them into the crack. Boring and adding a boss is a good suggestion, too.
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Originally Posted by BillE.Dee
A fellow that I know uses what he calls "ever doer" which I learned was EVERDUR. Boils down to sil/brz and he uses it all the time with great success. He told me to focus the heat on the filler rod and let it melt down on the material. he ends up with golden color every time. Its been a while since I've used either, but was able to get it done. I will go to the shop and give it a go on some stuff in the broken hopper.
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Originally Posted by tapwelder
I just tired this tip— Focus on hearing the filler. I guess it was successful. I started with 20 amp, progresses up by 10 to 20 amps. Reached 70 amps before I was comfortable with travel speed and wetting. I was working with 1/4 inch to 3/16 plate, fillet. It was consistently gold. I flows sluggishly, but fed wet out and was relatively easy to manipulate, but no capillary action. Maybe more heat? Ion kno. Or work in reverse, until the base metal doesn’t readily melt. Ion kno, again. We Good luck Fab54.
Reply:I did kind of a similar repair on a valve for my bender. I think I posted some of it here. My crack was pretty straight and perpendicular to the pipe threads. It held, but the valve body warped slightly and was a little more stiff afterwards. With TIG, I really struggled with the penetration/capillary action. So my suggestion would be to use a torch instead of TIG. More uniform and thorough heating that way. Best repair might even to be to clean it all up and braze in an adapter fitting. O-ring to JIC for example. Then put a new end on the hose.My name's not Jim....
Reply:https://www.grainger.com/category/we...72ea1245ebe27f
Reply:Here is an update. I practiced a lot and didn't feel comfortable with my skills so I took it down to our local reputable welding shop and asked how much it would cost to braze that little piece. The guy said I can't tell you how much. I said I just want it brazed. Nope I can't give you a price. We don't know what kind of cast iron it is and we might have to try different things. Ok so I can buy that. What I can't buy is that the guy couldn't even say it might cost you $100 or $200 or whatever number based on his experience for a half inch cast iron braze. There had to be some ballpark number in his mind even if it wouldn't be a firm quote. I felt like saying ok fix it I'll write you a check when you give me the bill for $1000. So I went home discouraged and just decided to braze away and see what happens. Boy that casting takes a lot of heat.I have a torch but the tanks are empty and 30 years out of date so that isn't an option....The hole is actually just a plug, straight thread that uses an o-ring. The hole/plug was put there for machining access inside the valve. It's possible that JB weld would have worked.Last edited by Fab54; 19 Hours Ago at 08:26 AM.Millermatic 211Lincoln Precision TIG 225Century 250 MIGLincoln 225 AC Box (sold)I support my local welding store (Amazon, McMasterCarr, Cyberweld, EBay).
Reply:Can't edit. Sorry it is a plug that has a spring and ball under it to allow right/left brake pressure equalization when both brakes are pushed.Millermatic 211Lincoln Precision TIG 225Century 250 MIGLincoln 225 AC Box (sold)I support my local welding store (Amazon, McMasterCarr, Cyberweld, EBay).
Reply:OK, here's what I learned. Personally, I can't make out the picture. Is that a large chunk that is broken from the body or just a groove cut in the o ring groove? IF it is a broken chunk taken out, you might be able to machine the threads out, insert a sleeve, weld the sleeve to the body and recut threads in the sleeve. I've talked to equipment mechanics who have tried to reweld valve bodies and it failed due to the high pressure and the valve body being impregnated with oil. I don't have any cast parts to mess with to see what happens with Si/Brz or Al/Brz filler, BUT, do know that the Al/Brz wants to be done on AC tig I wish I could provide better info.
Reply:
Originally Posted by Fab54
Here is an update. I practiced a lot and didn't feel comfortable with my skills so I took it down to our local reputable welding shop and asked how much it would cost to braze that little piece. The guy said I can't tell you how much. I said I just want it brazed. Nope I can't give you a price. We don't know what kind of cast iron it is and we might have to try different things. Ok so I can buy that. What I can't buy is that the guy couldn't even say it might cost you $100 or $200 or whatever number based on his experience for a half inch cast iron braze. There had to be some ballpark number in his mind even if it wouldn't be a firm quote. I felt like saying ok fix it I'll write you a check when you give me the bill for $1000. So I went home discouraged and just decided to braze away and see what happens. Boy that casting takes a lot of heat.I have a torch but the tanks are empty and 30 years out of date so that isn't an option....The hole is actually just a plug, straight thread that uses an o-ring. The hole/plug was put there for machining access inside the valve. It's possible that JB weld would have worked.
Reply:
Originally Posted by Fab54
Here is an update. I practiced a lot and didn't feel comfortable with my skills so I took it down to our local reputable welding shop and asked how much it would cost to braze that little piece. The guy said I can't tell you how much. I said I just want it brazed. Nope I can't give you a price. We don't know what kind of cast iron it is and we might have to try different things. Ok so I can buy that. What I can't buy is that the guy couldn't even say it might cost you $100 or $200 or whatever number based on his experience for a half inch cast iron braze. There had to be some ballpark number in his mind even if it wouldn't be a firm quote. I felt like saying ok fix it I'll write you a check when you give me the bill for $1000. So I went home discouraged and just decided to braze away and see what happens. Boy that casting takes a lot of heat.I have a torch but the tanks are empty and 30 years out of date so that isn't an option....The hole is actually just a plug, straight thread that uses an o-ring. The hole/plug was put there for machining access inside the valve. It's possible that JB weld would have worked. |
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发表于 2022-9-16 15:52:11