Cast Aluminum Welding Recommendations

I need to relocate some holes on M/T Cast aluminum valve covers. I'm not a great TIG welder but I can fake my way through it. I have had some formal TIG training.

Can you recommend a filler rod that would work best with the cast aluminum?

Also I need to make some small plugs that I will weld into the valve covers. What material would you use? I have mostly 6061 and I know that is not a good choice.

I use 4043. Never had an issue regarding filler. Sometimes alu castings are porous enough to make it difficult to get all the oil out. If you're not doing a lot of plugs I'd cut them out of another casting.

It may not matter for your particular job, but the repair will probably be a different color than the original material.

Stuart

atomarc said:

It may not matter for your particular job, but the repair will probably be a different color than the original material.

Stuart

Click to expand...

Yes, and it could well have a very different texture too if repairs are being made to an as-cast surface.

Thanks!

Well now that I finished locating the holes, I think that I will make the plugs and just press them in. Will make a stop so they should be good - no welding on the plugs. But you can see where I broke through the castings and I will weld that from the inside and then remachine.

I am aware that the color will be different but it is what it is. I did not want sheet metal valve covers (nostalgic about these covers) and I was damned to make these fit. The new head has a different rail pattern than the valve covers and the valves are moved 0.050" off centerline. I made a 1/2" adapter that I o ringed and I had to move the valve cover centerline 0.175" so that is why I have bolt hole problems in the valve covers. Overall quite please with the results.

I would worry that to tight a press fit might crack the casting and to loose might fall out or leak oil. Instead of pressing them in I would countersink both sides a little and rivet it in. Probably do it cold with a hammer. Heat the plug if it wants to work harden and crack. Just cut the plug a little long to have enough material to squish out into the countersinks. To long is better, you will machine off the extra. Make it a snug fit to begin with. It will deform into the countersinks and will never come out.

Looks good to me. I don't think there will be any problems just welding up the holes and refinishing the outside.

Good suggestions. Thanks!

I will stare at it a bit before I decide how to deal with it.........

Don't forget Loctite for the plugs - wonderful stuff , …..or even threading the plugs and Loctiting them in to place.

Welding on aluminum that has oil in its pores is not going to go especially well. Those covers need the oil baked out first, but I think Sami’s suggestion above is a good course of action. Plugs will look the most uniform, given the color difference between cast and the plug.

Yeah since those have been oil soaked you'll not get pretty welds. You need to crank the cleaning action on the balance and just wash over to get the smut out, stainless brush, acetone, rinse and repeat until you're getting a puddle without bubbles and crap floating in it.

I would just make a washer that fits into the cutout and put some Ultra Seal on them.

Well for better or for worse they are done. Too many mistakes - some self induced some natural but I recovered pretty well from them, just took MUCH longer than I expected.........

These covers are not in great shape and if I decide to do anther set I now know how to do them. Lots of learnings.

I had a piece of valve cover cut out of another cover where I cut the top out. I practiced welding with it and it scared the daylights out of me! As soon as I got a puddle it bubbled like a volcano. Major contamination caused the bubbling so I ground it and played with it and it was not pretty at the end of the day but I had no choice but to go for it.

I cleaned the covers for 3 cycles in the ultrasonic cleaner - normally would be only 1 three minute cycle. Sanded the weld area and then final cleaned with acetone. Low and behold it welded decent. The welds are not too pretty but totally functional. Had only a little bit of contamination.

The corner piece in the picture got whacked by mistake with a 1/2 inch end mill. Welded it up and sanded flat and you cannot tell it was repaired sans a few extra scratches. Color is about perfect.

As far as the bushings I tried all the options - slight press, loctite, peening and welding. At the end of the day the best solution is a slight press, peened on top and welded on the bottom.

Thanks for all the suggestions!

Great looking job Mr. You can weld up my Aluminum stuff anytime you want.

Stuart

You did really good for cast aluminum soaked in oil. They look nice

I don't envy you lol, nice work