What do I weld A242 cast aluminum with?

By Brent Date 03-29-2001 18:40

Good Day!!
I am trying to do a repair on a cast aluminum cylinder head and havn't been able to discover how it can be welded. I'm under the assumption that this is a not very weldable Magnesium/Nickel alloy but I believe it is done in industry... With what filler metal??? for GMAW. The welding Handbook mentions it as an almost non weldable casting... that leads me to believe that it has been welded!!! Brent

By airweld (**)

Date 03-30-2001 04:47

My AlcoTech catalog says A242 is most commonly welded with 4145 rod. I have welded cylinder heads of unknown composition with 4043 and as far as I know they held together. Scott.

By BP Maas (**)

Date 03-30-2001 17:44

The filler metal is 4145, preheat to 150 degrees F, let the casting cool in 70 degrees F or warmer air when the welding is complete. Make sure the casting is completely free of any grease or oil, use carbide burrs for joint preperation and a clean degreased stainless steel brush for oxide removal. If you don't have a TIG welder, find someone that does, Mig would be tough. Make sure you do a crater fill technique at the ends of your welds, if you don't you will get cracking in th weld.

Regards, Brad

By Darvin

Date 03-31-2001 08:28

Brent,

Are you saying you think you have A242? Or, your sure you do?

Just asking because I'm not sure. A356 is often used for cylinder heads.

Be careful where you use 4145 or 4043 on your casting. Those fillers have about half the tensile strength of A242. Your looking at about 40 ksi compared to about 24 ksi (I could be off a little).

If your repair is in the valve seat area, I would be concerned with those fillers. I might look into the possibility of using parent metal if that is the case. Some casting alloys are available in rod form. You might call your local welding supply.

The advice about TIG is good advice.