Re: Repairing cracked castings


Greg wrote:

> "John" <johnmanders@xxxxxxxxxxxxxxxxx> wrote in message
> news:1137354659.091833.50490@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > Have you considered brazing it? The lower temperature and better
> > workability make it a much easier repair. No guarantees though.
>
> Thanks for all the advice so far, a few more details might help:
> It supports the read bearing of the alternator via 3 'legs' of which the two
> thinnest are cracked right through, so no need to stop the crack running
> with a hole 8-(.
> What's left isn't strong enough, in my guestimation, to be left as is.
> I don't have gas welding gear, though I have done it in the past so realise
> what a specialised job cast iron is, I only have stick and MIG. Even if I
> did I wouldn't dream of trying it myself.
> I don't have brazing gear anything like big enough for this, and no oven to
> pre-heat it.
> I'm quite prepared to hand it to a specialist, in fact I'm very reluctant to
> try anything for myself because if this part is lost the only hope of
> salvaging the set in it's original form is to find someone with a
> replacement, not easy would be my guess. Unfortunately I'm in a backwater
> near Filey so specialists are few and far between, I'm really hoping to
> discover what type of specialist I'm looking for, welding, brazing, powder
> spraying etc.
>
> Greg

If the casting you are attempting to repair is thin in section.then TIG
brazing would be the way I would repair it. Could possibly need
pre-heat, but this is no where near as critical as if you were using
MMA (stick) welding process, which is better employed on heavier
castings.

Anyone thats good with a TIG set should be able to help you with this
sort of thing, and you might find a local marine engineering shop who
could help with this.

As to having a new part cast, this would be very costly and is really
only a senisble option if your original part is beyond repair or
missing entirely.

.

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