Cast Aluminium Repairs

Heard how difficult cast aluminium repairs are? Want to know how to preform such a task? Look no further.

So, there is a big stigma around welding aluminium. Especially when it comes to cast. Let me tell you there will be lots of hair pulling and possible the creation of new swear words. But that’s just welding aluminium, we haven’t even attempted cast yet.

Now if you are like me, I find welding cast easier then welding normal aluminium. Why? Well, it’s simple. Cast aluminium is generally thicker, harder to get to hot and if just more forgiving.

Why did I like cast repairs? Because it looks challenging but it’s easy!

Heres how to do it.

Now first thing is, cast is dirty. Its full of impurity’s. Its normally old and beaten up. It must be clean. Take the time to clean all that shit off it, don’t just rush in. This job was especially hard as was repairs prior with metal mend.

I normally give it a hit with the wire brush and flap disc, but remember aluminium is soft the wire brush or a wire wheel will eat it. Once it's looking a bit nicer, giving it a wipe down with some acetone.

The cast aluminium now looks clean, but it still isn’t. there it a massive amount of impurity’s hiding deep into the cast. To get rid of this I like to wind the amps up on the tig and simple create a weld pool.

Without adding any filler just run the tig over the area we are going to weld and all the Impurity’s float to the top (see the black stuff throughout it). This is the time consuming part. I spend hours on it. (The cast in the photo is actually a dog clutch housing for a speed boat. Old boat with years and I mean years of work made it extremely difficult. The impurity's just kept on coming.)

Then just hit them with the flap disc or die grinder, keep doing it till there is none left and she’s ready to weld. You might find you will have to run way back past the point you are repairing, as the impurity's will cause dramas when your welding it.

In this case we are just building up new material to replace the missing bits.

Now it is my favourite part. Just keep stalking welds to build up the area that need to be filled. But remember to fill, every gap or hole that may be there. If you fill a spot and now have no access to that area to weld just die grind it back out. Look at the bright side at least its clean now.

I like to weave the weld, so it covers/fills more at a time and because I think it looks cool. Also very good practice to get your welds consistent.

It can be a long tedious process, but it will be worth it trust me.

Once its filled (normally more than needs, because its easy to take away then it is to add)

Just grab the grinder back out, (or in this case with it being a sealing surface use a mill) with a clean flap disc. Shape the built-up area back to oem.

After its Shaped I just re-drilled and re-tape only holes, and sent it out the door.

There you have it, wouldn’t even know it was repaired. Just remember TAKE YOUR TIME. If you think taking it slow and careful its wasting time. Just wait and see how long it takes if you rush it. You will most likely have to do the job more then once.

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Thankyou,

H