Welding Mercury cast aluminum

[blen]

Hi I have a small weld to do on a 1/4 inch piece of Aluminmum on a Sport Jet pump housing. I have a TIG machine but hope to do it with out removing it from the boat which means I will have to do it upside down. I am sure it is the same material as all of there Gear cases and was looking for tips as far as Prep filler Material etc. Thankyou.

[Jay Smith]

I brush the Alum to be welded with a SS brush, clean of completely with acetone and heat up the area before firing up with tig. I use heli arc alum. rods ( I think I remember ) in the 3000 series I find it to be easier to tie in with a bit lower melt temp to the cast alum trash metal....

Good luck,
Jay

[jerry1865]

AMEN to all of that. just one trick to add. when the area has been pre- heated check to see how much trash is still in the metal.
there have been a couple of times that i had to really cook cast alum. one was a truck manifold . it had to cook at 900 degrees for about 7 hrs before it was clean enough to weld