Alu rod material for welding of heads?

[PH1303]

I have a set of Limbach heads, which needs welding in different locations before they can perform proberly. So the big question is what materials is okay to use?

Any other information regarding preheating of the head before welding, slow cooling after welding etc. would be highly appreciated.


/Peter

[wph]

I had a set of heads welded recently, mostly in combustion chambers, around seats
and plugholes. 5356 filler rod, preheat to 200 degrees before welding, any oxidizing
or "dirty" base material was removed by carbide burr or stainless wire brush.
Slow cooling in a roll of glass wool insulation, very clean and nice welds, filled
areas seem to be slightly harder than base material which was heat previously treated to T6.
I'm not shure about the base material, maybe 356 ?? , old Bugpack SF heads.

[PH1303]

Thanks....

/Peter

[AJ]

I use 4047 fillerrod also named alsi12 also 4043-(alsi5) can be used, both are suited for cast aluminium like 356 and similar, its less prone to give cracks and very smooth to get a nice puddle to begin with.
And and as wph says preheat to around 200°c and let it cool in a bed of glas or rock wool.

The last ones I welded were lying in the rock wool bed for about 24h and when i lifted the top layer they were still between 70-80°c.

Most important, don't rush with the cooling.