Welding Aluminum Structures to Galvanized Steel 1

[cmbyrd77]

I have a situation where I am connection aluminum handrail to a galvanized HSS tube, therefore a welded connection is the better option. However, once they make that weld to the tube and the galvanizing has burnt off wouldn't the connection be susceptible to galvanic action again? Would cold galvanizing or painting the connection be enough to prevent this? I feel like this must be more of a common issue then I realize because think of all the aluminum guardrails that are fastened to edge beams or edge angles. Thanks in advance for your help.

 

[MikeHalloran]

You won't get that far.

Fusion welding aluminum to steel is not possible because of their different melting points.

( Shipbuilders bond aluminum superstructures to steel hulls by means of strips of aluminum and steel that have been detonation welded. I don't think detonation welding is possible for forms other than flat strips edge to edge, or maybe lap joints, so that process is probably not available to you. Please let us know if I am wrong. )



Mike Halloran
Pembroke Pines, FL, USA

 

[Ron]

Not to mention the fact that metallurgically they are vastly different.
Aluminum does not oxidize in the same manner as steel so it cannot generally support arc fusion as MikeHalloran noted. There are exceptions for aluminum-to-aluminum welding (GMAC process with appropriate shielding gas can be used), but not for aluminum to steel.

In short, you can't weld aluminum to steel or likewise.

 

[rb1957]

and corrosion issues ...

don't do it !

if you Have to join them, weld a steel stub onto the steel, so that the Al tube will fit over it, and cross bolt.

Quando Omni Flunkus Moritati

 

[Gumpmaster]

Aluminum handrail is connected to steel all the time..... with bolts.

Bolting is the most common, and only practical, way to do it. Be sure to place a bitumastic paint or other barrier between the aluminum and the steel.

 

[msquared48]

J B Weld?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[samnac]

use bolted connections or use the same material

 

[boo1]

or grouted socket

 

[SAIL3]

concur with all the above.....this why there are off-the-shelf fittings for aluminum H/R...check out the BLUM website for all the fittings you will need...