Dis-similar metals?

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Hey folks, I was welding a broken clutch lever on my little Nissan yesterday and had a problem with making a reinforcement gusset hold. I am not sure what the metal type on the lever arm is but I know its not Alu, the metal I tried to use was simple hot roll flat bar of near same thickness. What happened was a weak tack between the two pieces that broke in the middle of the tack not on the two parts. Because I had a decent patch bead where the crack was on the arm I stopped trying to pump more heat and potentially make matters worse. All metal was brushed clean BTW so there wasnt any corrosion around the tack areas. - So is it dis-similar metals maybe?- Should I try some 1018 CR instead?- Should I just give it more juice and hope for the best?I dont want to just leave it as a patch bead where the crack was because basically I don't trust it and reinforcement is easy.Then again maybe I am polishing a turd and over thinking it...wouldn't that be a new one for me!
Reply:After 81 views I am just throwing a BUMP in the spirit  of hail mary...Last edited by DUCE00; 05-05-2011 at 11:24 PM.
Reply:Picts wouldn't hurt. So would basic info on your machine, settings etc..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:You've successfully made a weld on the arm itself and are having trouble getting the gusset to stick, correct or no???"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:Originally Posted by DUCE00Hey folks, I was welding a broken clutch lever on my little Nissan yesterday and had a problem with making a reinforcement gusset hold. I am not sure what the metal type on the lever arm is but I know its not Alu, the metal I tried to use was simple hot roll flat bar of near same thickness. What happened was a weak tack between the two pieces that broke in the middle of the tack not on the two parts. Because I had a decent patch bead where the crack was on the arm I stopped trying to pump more heat and potentially make matters worse. All metal was brushed clean BTW so there wasnt any corrosion around the tack areas. - So is it dis-similar metals maybe?- Should I try some 1018 CR instead?- Should I just give it more juice and hope for the best?I dont want to just leave it as a patch bead where the crack was because basically I don't trust it and reinforcement is easy.Then again maybe I am polishing a turd and over thinking it...wouldn't that be a new one for me!
Reply:Probably pot metal, which is cheap and low quality. I have never been able to weld it well.Could also be a magnesium alloy. But I doubt it
Reply:First check it with a magnet. ( AS OLD IRON 2 said) That is a basic step to identify the base metal.Some aluminum has a very high zink content. It will glow green if you attempt to TIG weld that type of material. You will need a special filler for that metal. It is available.It could be sintered metal, which is a compressed powdered metal. Is it is a complex shape?That type of metal also has a special filler  available. When you attempt to weld that type of metal it may sweat out an oily substance.They use that process  to make exhaust manifolds and other complex shaped parts.If it hardened steel it may not be weldable without the proper procedures and heat treatments.You have to identify the base metal before welding anything.Last edited by Donald Branscom; 05-06-2011 at 02:16 PM.Reason: spellingAWS certified welding inspectorAWS certified welder
Reply:Pics could help.As mentioned, without knowing what the metal you are welding to actually is, you are just guessing.Welding steel (you gusset material) to aluminum = Nope.Welding steel to anything other than steel = NopeWelding steel to -some- types of steel could also be a nope (powder-metal steel, some cast steels, etc).I don't know what type of metal your clutch lever is made of, but most of the pedal levers on plain production cars that I have seen seem to be made out of various 'plain' steels.  Which are usually weldable without too much difficulty.btw, for the most part hot-rolled OR cold-rolled mild steel are both usually weldable without too much difficulty.  The best laid schemes ... Gang oft agley ...
Reply:Thanks for the tips! Sorry I didn't jump back in sooner after the BUMP, I had some network issues that threw a wrench in my works for a couple days. I will work on getting a pic although I was using the stock HF flux wire in a cramped position so it looks like bird S#!^.@ Sandy- Yes I successfully patched the crack in the arm and the lump of material (its no bead trust me) is holding it together.Re speculation on arm material - It is definitely magnetic and the original manufacturing of the part used a welding process where the rod into the tranny meets the arm which the cable mounts to. My welder settings were on the Harbor Freight Dual MIG 171 and are kinda "relative" due to there being no actual amp or wire speed units on the face, just numbered settings. For amps it was set to 5 (of 6) which can be estimated as about 15% less that its full 140 amp power. For wire speed I had it set to 5, which is in range of the advised speed for .125" material. The prep of all welding surfaces was pretty meticulous and I see no problems there. What is the main issue for me here is that my patch weld is no doubt rather brittle and of really questionable integrity IMHO. By making a reinforcement I can add insurance to the area and distribute force over a wider area. When the little bastard broke, I had to get a tow home from my neighbor and I never want to suffer that experience again if you get my drift.Thanks again for the advice, I will update soon.