Best way to repair this casting?

[The Black Flash]

This is an ally casting which is part of the cooling system; the thermostat housing bolts down on top of it.
One of the bolt holes has cracked at sometime in the past, and it's been repaired with epoxy putty. The crack doesn't penetrate into the water passage, so it's purely a bolt hole.



These are getting a rather hard to get hold of now, so I'm looking to repair rather than simply replace.
Can it just be TIG'd back together and re-drilled? Or does cast ally not weld well?
Otherwise, I can re-putty it. Or perhaps try to drill further down (there's a few mm at the bottom of the hole) and fix a stud in there.

Any other ideas?

[Justin S]

Not sure on casting and welding, but i know alloy heads can be rewelded and machined afterwards. Bit labour intensive, but will bring it back to as new condition.

[S1_RS]

Grind it back as far as possible to expose the threaded section so it can also be ground back or drilled out slightly larger. Build up the stud hole with weld gradually. Re-drill hole and re-tap.

[eliot]

It can be repaired as said, by cutting it back with a die grinder, thoroughly cleaning, tig weld with a 5 or 10% silicon rod, drill and tap. the top face looks like it needs maching flat too.
Expect to pay around £100 for the work.

[Nick3point2]

You want some JB weld. Brilliant stuff.

[The Black Flash]

Thanks all. I'll see if I can find a friendly man with a TIG set.

[A Scotsman]

Which car is that from?

[ColinM50]

Buy a new one.

By the time you faff around trying all different sorts of products or paying someone to weld it for you and and and, you'll be quids in by buying a new one. Can't be that expensive or hard to find.

What's it from? Betcha you can find you one for a tenner

[V10Mike]

I had a similar problem with the cast aluminium coolant pipe on my Alvis:

I repaired it with HTS-2000 brazing rod and a MAPP torch:

[bob1179]

V10Mike said:

I had a similar problem with the cast aluminium coolant pipe on my Alvis:

I repaired it with HTS-2000 brazing rod and a MAPP torch:

Lovely bit of repair work there.

I do like seeing something that look irreparable being brought back to life.

As for the casting, it can be repaired as mentioned, I would personally get it fixed, especially if it is a rare part. What is it from?

[eliot]

Nick3point2 said:

You want some JB weld. Brilliant stuff.

Filling it up with pudding is not repairing it is it?
If the item is only 50-100 to buy, then dont waste your time - replace it. Only rare Items justify the expense of repairing how i described.

[Boosted LS1]

I'd bore it, plug it, weld it and then tap a new thread.

[stevieturbo]

Get a replacement CNC'd from a nice chunk of billet.

Yes it would be expensive, but it'd sure look good

[The Black Flash]

It's from a 12v alfa v6, pre 1990s. There have been various designs over the years, and this one suits my purpose, but unfortunately I'm not sure exactly which cars/engines had this particular one. All this conspires to make it hard to find, it was hard enough tracking this one down through a specialist breakers. It's not a part which normally ever needs replacing so I doubt many people bothered keeping 'em.
Happy to be proved wrong though

[The Black Flash]

V10Mike said:

I had a similar problem with the cast aluminium coolant pipe on my Alvis:

I repaired it with HTS-2000 brazing rod and a MAPP torch:

Beautiful job.

[stevieturbo]

The Black Flash said:

Beautiful job.

Would have to agree.