welding cast aluminum but hardened

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ive searched around for welding cast aluminum and found some answers but ive found little about hardened cast aluminum.  I have a car differentional housing carrier that is made out of cast aluminum which i assume is hardened.  The piece has two ears off on the sides that hold bushings. i needed to cut the metal sleeves that are pressed inside.  I had to take a saw and cut the steel sleeve to get them out.  I went too far and cut a little into the aluminum.    This is the unit im talking about i dont have a picture of my piece with the cut, but thats an idea of what im working with.   anyways.. i want to fill in the slice i made just in case there is any structural damage which may cause me a problem down the road.  I had a licensed welder at work tell me it would be more dangerous to weld it than leave it since it would be heated up to above 400 degrees, thus ruining the hardening of the aluminum.  Is this true? or could it be filled while keeping it strong.  i know very little when it comes to this.  thanksthanks for the forum use.
Reply:Its not very clear where the cut is in relation to the part.  If it is just out where the rubber mounts go just weld it up.  cast aluminum is not hardened as far as I know. Iv'e been welding it since the early sixty's. It does however warp under some circumstances. thats why it would be nice to know where and in which direction you made the cuts.  Mac
Reply:sorry it was unclear.  the cut goes from opening to opening in the ear.  It goes from 0 to about 3/32" deep from side to side.  (cut at a slight angle).
Reply:You would do more harm than good. File down the edges of the cut to smooth them out. Throw it back together and forget about it. Not gonna matter
Reply:if it aint more than 25% of the material thickness i wouldnt worry about itLast edited by assassin_works; 09-17-2012 at 10:13 PM.Lincoln Power Arc 4000 Thermal Arc Fabricator 252 iThermal arc 186Thermal Arc 26 tigTweeko 200 amp spool gunHobart AirForce 400WP-17V-12R
Reply:The rubber will take most of the shock out of that area.  As said just assemble and ride. Mac
Reply:Not an issue with is part, it'll be fine as is, but "speedi sleeves" work great for filling in grooved out shafts and bosses.They are thin sleeves that are pressed into place. If the grooves are deep it's best to fill them with jb weld or belzona first.
Reply:Next time just burn out the rubber bushings with the torch and clean up the bores with a flap burr.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:I've recently started using a so ph3050 for bushing removal. It makes it cake. I can do mustang 8.8 bushings top/bottom in car in a few minutes. Use a pointed chisel to collapse the shell, then a chisel tip to push it out. Heating/burning out the bushings is likely to affect the temper of aluminum.Miller: 200dx, Bobcat 225, Passport, Powermax 45, Milwaukee: Dry Saw, MagDrill, grinders
Reply:On the pressed-in bushings, I've found that the best way to get them out is to first heat the interior steel sleeve with a torch (a Bernz-o-Matic works just fine), until the center sleeve is hot enough to melt the rubber that is bonded to it, thus allowing easy removal of the middle sleeve.  Then you can either press out the outer shell or chisel it to deform it inward pretty easily, in order to allow its removal from the suspension piece.  This way, when you're heating the sleeve, the heat isn't getting to the aluminum part.  I spent no less than 40 hours on the project when I swapped the Energy Suspension Master Bushing Kit into my G35 Coupe.
Reply:Next time run a pass of weld around the inside of the sleeve andIt will more than likely fall outMiller bobcat 225g  - spoolmatic 1Mm250 - 30a spoolMiller spectrum 375Thermal arc 95 Everlast Ex 250As the boiler turns, these are the days of our lives
Reply:here is the actual slice
Reply:Yikes, that is pretty deep.  I'd weld it......hot and quick.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:It's true, most cast aluminum is heat treated.  Aluminum alloys having Silicon and Magnesium (and even sometimes copper) are commonly used in cast aluminum, and are heat-treatable alloying ingredients.  When heated to 600-700 deg F, the aluminum alloy will lose its heat treatment and stress-relieves.  The area where this occurs is called the "heat affected zone".  Welding it will require elevating the temperature of the material that is liquefied into the 1200-1300F+ area, so there will be a heat affected zone in proximity to the weld.  What that means is that the heat affected zone will not able to take as much stress before it starts bending or "yielding".  It does not make the structure less rigid (the amount of strain or movement it takes for a given amount of force, below this bending point.)  And many heat treatable alloys will naturally harden over time (at least to some extent.)Based on where the weld would need to be, it seems like a doable repair to me by someone competent, as the heat affected zone could be maintained in a non-highly stressed area that is simply in tension, to keep the sleeved bushing from falling out.There are precision tolerances required for this repair, so it will need to be finished pretty carefully after the welding is performed to be able to press the bushing in without undue resistance/interference.  It sounds like the guy you spoke to was shying away from this for liability reasons, and/or probably the budget (if you did discuss one, or that he may have assumed you had) just didn't justify the risk and/or time required for him to take the job.  Or maybe he's too busy with other work to take on new work.  You could try shopping around.  You'll need someone competent at welding aluminum to fix that.Where are you located?
Reply:The hole recieves a rubber(poly) bushing  with a metal sleeve, they are typically pressed in .? So the slice is a stressor which may over time cause a crack.All aluminum is heat treat..... It's an alloy....It's a simple repair....Get in, get out, let cool slowly...Jackeroo why are you making a mountain of a mole hill?Miller bobcat 225g  - spoolmatic 1Mm250 - 30a spoolMiller spectrum 375Thermal arc 95 Everlast Ex 250As the boiler turns, these are the days of our lives
Reply:Tack to side your gonna finish on, weld into the tack. Fast in, fast out.Miller bobcat 225g  - spoolmatic 1Mm250 - 30a spoolMiller spectrum 375Thermal arc 95 Everlast Ex 250As the boiler turns, these are the days of our lives
Reply:Thanks for the clear explanation. I'm in mass around the Boston area
Reply:astainedsoul - not all aluminum alloys are heat treatable, as you claim.  5xxx series (Magnesium alloyed with aluminum) commonly used in marine applications, are one example.
Reply:It's cast..... Odds are its not 5xxx series, but you are indeed correct about post heat treatment.Miller bobcat 225g  - spoolmatic 1Mm250 - 30a spoolMiller spectrum 375Thermal arc 95 Everlast Ex 250As the boiler turns, these are the days of our lives