Weird weird cast weld

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So my buddie brings this piece to me today. It is a footpeg bracket off his kids little pocket bike. He (my buddie) was riding it and plowed a curb  so rather tell his kid that daddy broke his toy he had another guy "weld" it. He was able to break it back apart with his bare hands. I think the other guy must have used some kinda alum flux rod. So I start cleaning all the crap outta it. I have done some cast alum on like transfer cases and such so I just used my normal procedure. Clean, heat, scrub with ss brush, V out the joint, heat, clean, scrub some more, weld the crap outta it. WRONG!!I seen colors come off this thing that I havent seen since my last acid trip 15 years ago  Pores big enough to drive a pickup into and just dirty as a $2 hooker. At first I thought Magnesium. So I took some filings and held a torch to it..nothingNow if it had been for a street bike (or even a dirt bike) I would have stopped right there and told him "Sorry bud but you are gonna be buying a part" but.... I kept going, I finally got it to start sticking together and suddenly this silver blob pours from under it . I think they just took whatever nonmagnetic scrap they had and melted it together to pour this part. Sigh. grind, scrub, clean, cuss, throw brush at said buddie when he walks by. weld more.After I got done I gave it the 4 foot drop test (it passed) and told him it came with my 2 part warranty. If it breaks into  2 parts he gets to keep both and don't ever bring me that POS again. I would have taken pics but left my cell phone @ home today. FWIW the set upsyncrowave 2502% ceriated 3/32 tungsten.100 or so amps30% balance no pulse4043 filler
Reply:Die cast?? Aluminum & zinc??"The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Its probably a zinc alloy or whats commonly called a "pot" metal casting.  In either scenario it does not sound like something that is weldable.Have we all gone mad?
Reply:I've seen some auto restoration guys do amazing things with old zinc  pot metal emblems and such.  As I recall, they did all repairs with a solder rod using one of those muggy weld type alloys.  As far as getting structural strength into something like a pot metal foot peg, my best guess would be to drill both ends and put a stainless steel internal pin in it.  If it was the bracket for the peg, how about fabbing one up with some "real metal"?Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:larp,Welcome to "cast" anything.  Could have been pot metal, but then I don't think you'd have had "any" luck welding it.Any particular reason you set your balance on 30% on a Sync 250?  That's way too much cleaning.  Think you'll have much better luck welding aluminum with the balance set between 7-8.Plus, you won't be overheating your tungsten nearly as much.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Something that might be worth considering is plain ole JB weld.  For stuff like this, its probably your best option.Have we all gone mad?
Reply:After thinking on it a bit I think the zinc is the best bet. I remember a bad experience with some not so clean galvanized pipe that had kinda the same colors to it. I also remember puking my guts out a short time later Doug, If it does break again I guess I will fab him up something outta some 1/4" alum. Thats just the kinda sucker..er....I mean guy I am. Sundown, My thought process was a wider arc to keep the penetration from blowing out the back side. Most of the time I do not move it off 7-8 (70%) for "real" alum.
Reply:larp,Pictures would really help.Sometimes, when dealing with cast, I find I really have to just go slow with the arc and sorta "nurse" the impurities to the surface adding filler as the puddle forms.  Then grind the impurites out.  Slow process that often has to be repeated a couple of times til I get a good base down.  Too much heat, too fast, will just cause a mess.Do you have enough room/material there to drill and tap the two pieces.  If so, you could go this route and insert a short length of SS threaded rod for reinforcement and just "fill" the aluminum.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I went to a State Fair once and watched a guy weld pot metal and boat propellers and beer cans with a propane torch and this filler rod that looked like silver sticks of heavy solder?  I bought some just because I was curious......Turns out that I never used it and it got thrown away........I think that might be your answer for Pot metal ......I think it is still on the market some where........do a Google search  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:TSC sells hobart brand rods. or they are under a bunch of names like alumiweld and durafix