Welding cast aluminum

[Fedup]

I'm wondering where/who to ask this question. Can cast aluminum be welded? If so, can it be welded to other aluminum, like sheet stock or plate?

I need to replace(or repair) a broken cast thermostat housing for a tractor made in Japan for International some thirty odd years ago with a Nissan diesel engine long gone from production for most of those years. I have feelers out for a used one with little hope there either. I'm thinking my only hope may be to fix it however possible.

I suspect the break is due to poor engineering from the start, and it might be salvageable if a plate can be added on the face of it, welded to it, then machined so it's flat where it mates to the cylinder head/gasket surface. I have little doubt the added thickness of the mounting flange will create any real issues with the operation, nor that the machine work can be done, just about the welding itself. If it can be done with a water tight finished product that can be trusted to stay that way.

Am I looking for something that doesn't exist? I know little or nothing about welding aluminum.

 

[bplayer405]

Welding cast aluminum can be done with tig. It's a slow process because casting aluminum traps a lot of impurities that will have to be heated out of the area needed to be repaired. A good welding shop should be able to repair about anything you bring to them, unless it would be more cost effective to fabricate a new part.

 

[Gary Fowler]

What bpplayer 405 said. Easy to weld, just takes a lot of cleaning to float out the trash in the casting. Welding clean aluminum plate to it will help the process a lot compared to just welding cast to cast.

 

[Fedup]

The part is in two pieces now, so the two need to be joined back and be water tight. The fabricated piece would be added to the flat surface where a gasket will deal the housing to the cylinder head. That of course would need to be water tight as well. I guess I need to find a welding shop and see what happens.

 

[Sberry]

We weld cast alum fittings with simple wire and spooly all the time

 

[Sberry]

Can melt the flanges off similar to simple fusion weld, really fast and thrifty with wire. Very rarely tig anymore.

 

[Gary Fowler]

I dont think anyone said it cant be welded, just that it will float out impurities just like in your photos with the porosity showing. Irrigation piping is no big deal if it leaks a bit but if you needed a pressure containment for something like oil or flammable liquids where you absolutely dont need any leaks, TIG would be the way to go and you would need to float out the impurities, grind, make another pass and possibly make more passes to get a solid weld. A spool gun works great for thicker stuff and even thin material if it is clean base metal.

 

[Sberry]

I think the pic makes it look porous, its some soot on the surface and maybe little coverage loss as I do these in about a minute. I see every post mentions if it was this and if it was that but it really isnt. This is connected to 050 and some 065 tubing and pumped at 150#
I agree dirty may need redone, I just brought in a fitting someone welded and it does have a hole and going to clean and zing another pass around it at some point. Also agree welding it to plate does make it better.

 

[evaliket]

I'm wondering where/who to ask this question. Can cast aluminum be welded? If so, can it be welded to other aluminum, like sheet stock or plate?

I need to replace(or repair) a broken cast thermostat housing for a tractor made in Japan for International some thirty odd years ago with a Nissan diesel engine long gone from production for most of those years. I have feelers out for a used one with little hope there either. I'm thinking my only hope may be to fix it however possible.

I suspect the break is due to poor engineering from the start, and it might be salvageable if a plate can be added on the face of it, welded to it, then machined so it's flat where it mates to the cylinder head/gasket surface. I have little doubt the added thickness of the mounting flange will create any real issues with the operation, nor that the machine work can be done, just about the welding itself. If it can be done with a water tight finished product that can be trusted to stay that way.

Am I looking for something that doesn't exist? I know little or nothing about welding aluminum.

We weld cast aluminum all the time on motorcycle engine case repairs and many times these are full of oil as castings are porous so anyone familiar with welding cast aluminum can handle it for you

 

[kpsp50]

Yes cast aluminum can be welded to anything as long as it's another piece of aluminum like State before has a lot of impurities clean clean clean all of my cleaning materials such as stainless steel wire brush and other items are specifically for aluminum and nothing else do not mix your cleaning items with still or copper then wipe down with acetone to get all the fine impurities out then start welding with Tig 4043 rod this is a picture of a 2 inch trash pump case they forgot to drain and cracked out it's all cleaned we'll go in an oven to get preheated when it comes out I will clean it with acetone and start welding on it

 

[Yankeenorth57]

I'm wondering where/who to ask this question. Can cast aluminum be welded? If so, can it be welded to other aluminum, like sheet stock or plate?

I need to replace(or repair) a broken cast thermostat housing for a tractor made in Japan for International some thirty odd years ago with a Nissan diesel engine long gone from production for most of those years. I have feelers out for a used one with little hope there either. I'm thinking my only hope may be to fix it however possible.

I suspect the break is due to poor engineering from the start, and it might be salvageable if a plate can be added on the face of it, welded to it, then machined so it's flat where it mates to the cylinder head/gasket surface. I have little doubt the added thickness of the mounting flange will create any real issues with the operation, nor that the machine work can be done, just about the welding itself. If it can be done with a water tight finished product that can be trusted to stay that way.

Am I looking for something that doesn't exist? I know little or nothing about welding aluminum.

From past years of welding similar items I would recommend welding the part with a tig welder. I would also say to create a solid flat plate to bolt it to so that the surface that attaches to the head will remain flat for a good seal with no leaks and also make sure to allow the assembly to cool before separating the part from the plate thus avoiding warpage and cracking. A good tig welder would be able to control the heat and any impurities in the metal for a quality weld on your part.