RE: Welding Aluminum and Steel - Exhaust Manifold Question

["David R. Lefebvre" <drl@xxxxxxxxxxxxxxxxx>]

We can send you the old part if you pick up the postage. Iron or carbon 
steel bracket, welded to an aluminum manifold. Let me know quick before my 
mechanic tosses it.

We had considered welding it, but for $140 for a used part from Bavarian in 
Rancho Cordova, as opposed to $400 from the dealer, we went with the 
former. Perhaps we were mistaken.

For the record, I have had an aluminum oil pan welded on an 86 Mercedes 201 
about eight years ago.

At 05:03 PM 3/17/03 -0500, you wrote:
>Ok, exhaust manifolds are not made from aluminum.  That is a true
>statement, at least as of this time.  In the near future, that may be
>another story as different alloys of aluminum are made.  It was not too
>many years ago that you could not weld aluminum by any method, but alloys
>were developed that are weld able by flame brazing using special flux and
>fill rod, by electric-arc using special fill rod and the right type of
>welding machine, mig using special wire and inert gas and by tig using
>platinum electrodes.
>
>It is not a true statement any more that you can not weld steel and
>aluminum.  The Russians have developed the process and have been suing it
>in their aero-space and military programs for years.  The major
>international OEM for which I used to work, purchased the technology from
>the Russians back in 1999 and I worked on developing the process so that it
>
>could be combined with Hydro-Forming to make vehicular structures (frame
>and sub-frames and frame parts).  It is done with special equipment and is
>done with a combination of electrical and magnetic pulses.  The final weld
>seam between the steel and aluminum is just as strong as that of 2 pieces
>of steel welded together by any method and actual pull tests document that
>the joint is stronger for the steel-aluminum.  But even for starting this
>development back in early 2000, on full sized Chivy and Caddy rear side
>members, which were 2 pieces butt welded together to make one, the one
>piece was aluminized steel and the other just steel.  Normal butt welding
>methods were used to weld them together.  In fact, the company that I
>worked for has several patents on the process based on the Russian
>methods.  It will not be long before you see this in some upper end
>vehicles to held reduce weight and make the structure more rigid.
>
>And to go another step, anyone with alloy wheels (which are made from
>aluminum) has found that they have been "welded" to their hubs if not
>removed for some time and nothing was "painted" on the wheel mounting
>surface of both the wheel and hub such as NeverSeize compound.  Galvanic
>corrosion is a type of welding as electrons are shared by the steel and the
>
>aluminum making a bond, though not as strong as a weld.
>
>Just thought I'd clear the air about welding steel and aluminum together.
>
>Happy motoring,
>
>tom
>BMWCCA Member
>former ASE Certified Tech
>former Prototype and Tooling Developer for DANA/Parish Structures Division
>(22 plus years)
>Journeyman Tool & Die Maker
>ISCET Certified Electronics Engineer
>'84 318i
>'85 318i
>'89 325ix
>'91 318is
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