Welding “Kinda-Aluminum”

Wondering what the consensus is on welding near-aluminum...

I’ve got Heli-Arc, 4043 and 5356 filler rods from 1/16”-1/8”... but I don’t expect either of these to weld real well period... honestly I don’t plan to even bother with 5356, unless someone chimes in with a good rationale.

Here’s the part(s)
GM factory big block valve cover:


I’m still kicking myself. I didn’t notice the gasket had a bit of mold “leavin’” that wedged under the cover and broke it.

Or, welding this filler cap into a set of cheap eBay valve covers:


eBay listing said “aluminum”, but it’s got that “pot-metal” grey written all over the as-cast parts:



The GM factory cover isn’t AS grey, but whatever it is, a guaranteed, graded alloy it likely IS NOT.

I’ve never had luck doing more than evaporating pot-metal parts into more than a cloud of what I assume, is highly carcinogenic, vapor.

In any case, both of these will be one-shot goes... I plan to strike an arc and try for a small bead before attempting the repair or to weld in the bung, but confidence is not high.

I’m totally open to tips, tricks, methods and ways of holding ones mouth whilst doing the above. 4043 and 5356 covers all the bases I need to stock, but maybe there’s an “aluminum mud-rod” I’m not aware of? I do have a several reasonably well stocked welding supplies near enough.

The eBay specials were cheap enough it’s no biggie if they go to the scrap bin. Chevy cover is already broken... I’m also considering a mechanical option to align the gasket surface and JB-Weld will keep the oil in. Not much actually considered “pressure” at GM valve covers. Mostly just need a bit of squeeze on the gasket and I should be okay.


Happy Father’s Day to all the dads out there.



Jeremy

jermfab said:

Wondering what the consensus is on welding near-aluminum...

I’ve got Heli-Arc, 4043 and 5356 filler rods from 1/16”-1/8”... but I don’t expect either of these to weld real well period... honestly I don’t plan to even bother with 5356, unless someone chimes in with a good rationale.

Here’s the part(s)
GM factory big block valve cover:

I’m still kicking myself. I didn’t notice the gasket had a bit of mold “leavin’” that wedged under the cover and broke it.

Or, welding this filler cap into a set of cheap eBay valve covers:

eBay listing said “aluminum”, but it’s got that “pot-metal” grey written all over the as-cast parts:

The GM factory cover isn’t AS grey, but whatever it is, a guaranteed, graded alloy it likely IS NOT.

I’ve never had luck doing more than evaporating pot-metal parts into more than a cloud of what I assume, is highly carcinogenic, vapor.

In any case, both of these will be one-shot goes... I plan to strike an arc and try for a small bead before attempting the repair or to weld in the bung, but confidence is not high.

I’m totally open to tips, tricks, methods and ways of holding ones mouth whilst doing the above. 4043 and 5356 covers all the bases I need to stock, but maybe there’s an “aluminum mud-rod” I’m not aware of? I do have a several reasonably well stocked welding supplies near enough.

The eBay specials were cheap enough it’s no biggie if they go to the scrap bin. Chevy cover is already broken... I’m also considering a mechanical option to align the gasket surface and JB-Weld will keep the oil in. Not much actually considered “pressure” at GM valve covers. Mostly just need a bit of squeeze on the gasket and I should be okay.


Happy Father’s Day to all the dads out there.



Jeremy

Click to expand...

The general has plenty of those covers in stock. At least you did not smash the right side cover on the left side guard rail in the kink at Road America...You would be fixing a lot more than a valve cover.

The General MADE plenty of these covers... unfortunately this specific one, with the Tonawanda Engine plate is one of the more rare variants.


I’ll stay on the hunt for a replacement.


Jeremy

I'm no expert, but maybe tig brazing is an option. Probably less likely to melt it (I don't know the melting point of pot metal). Brazing is good for dissimilar metals.

If it is cast aluminum you need to cook all the crap out with the tig torch and no filler. Unlike DC tig, AC cleans and going over crap will remove it. If you can adjust the AC balance on your machine that will be a big help but not totally necessary.

TIG brazing doesn't work on aluminum with any type of filler I am aware of. I would clean the paint off a good distance from either side of the break and bake the valve covers for awhile at around 450 degrees F to burn off all the oil and contaminants. Of course that may ruin the logos which seems to be the valuable portion of those valve covers.

I'd suggest using one of the gap filling solders meant for pot metal and crappy aluminum alloys. Less chance of the metal evaporating or fracturing.

I used to work at a die casting place that made GM valve covers, and they always used the same alloy, so I wouldn't worry about the composition too much. 4043 covers most cast alloys, but it's going to be a chore dealing with the filth. Pay attention to your cross section and adjust the amps accordingly. The transition out to the flange is going to be the crux, but you can get to both sides so it shouldn't be too bad.

I have tig welded those before, maybe because I didn't know it "couldn't be done"...
Cheap china imports, and factory covers, both. 5356, and take your time!

jermfab said:

The General MADE plenty of these covers... unfortunately this specific one, with the Tonawanda Engine plate is one of the more rare variants.


I’ll stay on the hunt for a replacement.


Jeremy

Click to expand...

Why do you care about the Tonawanda label? Most of that engine was never anywhere near Tonawanda.

Not that it matters, but most of the GM big blocks WERE indeed produced at Tonawanda. Pretty sure that they made more than stickers for valve covers there.
I care about these valve covers because they’re cool and they clear the brake booster AND the rockers. And I have them on hand. And since I’ve been furloughed since late-February I’m trying real hard to stretch me unemployment payments by not buying a bunch of stuff. The Chinesium ones weren’t worth the effort and are back on their way whence they came.


Thanks for the advice. I’m breaking the heli-arc machine out tomorrow and I’ll have a go at fixing the valve cover and making some exhaust:






Jeremy

I have used the solders like you see at car shows or late night tv for stuff like this with reasonably good success! I have used tig, propane, and oxy-ac if I needed more heat. When the regular fillers like 5356 don't work these will? Sometimes the best thing to use on crap is crap?