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Welding cast iron - machine broken in transit

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Barefoot-Leather:
I'm told by my local engineering company (blacksmith) that welding cast iron is virtually impossible but I've cracked a smallish bit on a lovely but ancient machine and there is absolutely no danger of ever finding another bit to replace it. To be honest, it isn't mission critical as the machine will work perfectly well without it, but t'would be nice to have the thing in one piece.

Can anyone please suggest somewhere I might get this work done? I'm based in Ludlow, Shropshire, UK. The broken bits weigh about a couple of pounds at a guess so could easily be posted.

I'm happy to trade leathery bits for a repair (okay, I know what I said but don't go there...).

Thanks for looking,

Ray

bogstandard:
Ray,

Cast iron can be welded, but it then leaves it wide open to distortion and cracking, plus it will most probably have to be dressed back to original shape anyway.

The safest 'heat' method is either bronze welding or brazing, again the surfaces will have to be dressed back to original, brazing being the lesser of two evils.

If the parts are large enough you can have them 'stitched' using tapered straddle pegs. A repair company comes out and does it on site, not cheap.

If it is purely cosmetic, with no heavy usage or pressure involved, then I would suggest a good chemi clean down, then stick the parts together with a good 24 hour epoxy (JB Weld or Araldite). Bearing in mind, if you do that, it will never be able to be heat joined afterwards, you will never be able to get all the epoxy out of the grain without copious amounts of work. Cast iron lends itself nicely to this type of repair, as the joints are usually very cleanly broken and fit back together perfectly. As I suggested, a good clean with say cellulose thinners, let it evaporate, spread a nice even coat over both surfaces, getting well into all the nooks and crannies of the break, then assemble and tightly clamp to squeeze all the excess adhesive out, ensuring the edges all match perfectly. Wipe the outside clean, and put to one side for a day for the adhesive to do it's job.
 
JB weld does a very good job of bonding metal, and I would recommend that over Araldite.

http://cgi.ebay.co.uk/JB-Weld-Industrial-Strength-Adhesive-J-B-Cold-Auto_W0QQitemZ350244192608QQcmdZViewItemQQptZUK_Measuring_Tools_Levels?hash=item518c2e4160&_trksid=p3286.c0.m14

A lot of auto accessory shops stock it on their shelves.

Bogs

Bluechip:
Ray

Bogs is as usual right. CI needs pre-heating before welding, a mate worked on 'em years ago. Did castings up to a ton or so .
Ditto Stitching I think. Firm long gone .... bugger. He sneaked two CI bike heads through for me once, 20 Senior Service I recall. Expensive !!
There are some contacts in the V M C C mag for CI welding. Probably a reasonably reputable source. If you want, I can look thro' the recent issues, and e-mail the info.

Your Call

Dave BC

John Hill:
Hmmm...it is small, it is broken, you have the pieces and it is cast iron.  Is there any prospect of casting another?

Barefoot-Leather:
Here are a few pictures of the riveting machine - and the broken bit so you can see the extent of the damage.

Bogs: Thanks muchly for the suggestion but I'm very wary of using epoxy as I'm a particularly mucky blighter and will doubtless get it everywhere. The machine is a treasure (IMHO) so I'd really like a proper job done by an expert, preferably before anything gets sand/shot blasted and repainted. Have a look at the pics and see what you think though...

Dave: any info gratefully received. Ta.

John: I would imagine that casting another would be hugely expensive - unless you know different?

Thanks all,

Ray

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