[TheForge] Aluminum welding

[Keziah's Forge]

What broke the piece in the first place  requiring the initial repair? Was 
the weld in approximately the same place as the initial break that required 
the repair?  If so, it sounds like whatever use the dump is getting is over 
stressing the frame at that point.  SOunds like the beam has to be replaced 
with larger stock for a foot or so to either side of where the recurring 
break is.  Even though your good weld should be stronger than the member it 
is repairing, it sounds like the member itself is being way over stressed at 
that point.
----- Original Message ----- 
From: "John Allen" <countrymetals at gmail.com>
To: <theforge at mailman.qth.net>
Sent: Wednesday, August 12, 2009 6:54 PM
Subject: [TheForge] Aluminum welding


>I welded an aluminum dump truck dump body frame rail together since a
> 4 foot section had to be replaced at the pivot end. I replaced the 6
> inch I beam with a new one and I welded it together. The owner has
> contacted me that the weld broke. I fixed it and gave it back. He now
> said it did it again. It is breaking from the top of the beam down.
>
> I made straight cuts and there was about a 3/8 inch between the old
> one and the new piece. I mig welded the outside after I cleaned the
> joint with a brand new stainless steel wire wheel and then aluminum
> cleaner, muradic acid. I welded it at proper settings and helium gas.
> I even cross stitched weld over the vertical weld to improve strength.
> I am using 4043 3/64 wire
>
> After it broke the first time, I asked other welders what I did wrong,
> they don't know. I am loosing my mind trying to figure it what I am
> doing wrong. I do not have a welder heavy enough to put out 250 amps
> to tig weld it but I do have a 302 trailblazer that I could run 225
> amps to tig it. I don't know what to do besides replacing the entire
> beam and eliminate the weld.
>
> -- 
> Sent from my mobile device
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