Welding /2 cases

[deyoung2837]

Anyone have recommendations for what TIG rod to use for repairing /2 casses?

Thanks for any information,

Lee

[caker]

Lee,

From my friend Kevin in Germany:

he's asking if my broken R5 head has "ALG2" or "ALG3" foundry mark. I'm guessing all later post-war castings were ALG3 or even better/newer, but read Kevin's info below about welding BMW castings and gotchas and what rod to use:

<Kevin> Alg3 or ALG2?

Alg3 is good weldable

ALG2 has more Cooper in the alloy . Weldable but gets worse

S3300 = more Cooper = super pain from the Backside

Tell the welder He shall use AlMg5 full rod !

AlMg3 also okay

Most people think they weld Casted stuff and AlSi3 is the choice but they fail

This Cast is Like hard Alu ....so AlMg fill rod flows like cream!

And almg Looks perfect in the end

AlSI makes pores

HTH,
-Chris

[jwonder]

Chris,

That information is gold!!! That will help all of us going forward!

[flyingtpot]

I still generally use ALMg-5, aka ER5356 for most of my exhaust thread repairs (TIG and lathe cut).

I collaborated with the apps engineers at Alcotec and for BMW pre-70 cases welding repair, and other BMW cast aluminum parts, and the recommendation was to use ER4145. It is more expensive than some other filler rods, yet the cost difference is negligible when factoring in ER4145's capability. The flow with it is excellent. The downside....Alcotec/ESAB has discontinued offering ER4145. Search around and it can be found.

It should be noted, different filler rod materials should be used for different engine case repairs types. The type of repair, structural vs. cosmetic, will determine what is the ideal filler rod. Repairing a nick, gouge or surface blem can require a different filler rod versus repairing the engine case rear M12 mounting bolt feature.

[lauryfriese]

To ensure a compatible and strong weld, it's generally recommended to use a TIG rod that matches the base material of the casting. Determine the type of metal used in the /2 casting and select a TIG rod with a similar composition. Candy Crush