MadModder
Gallery, Projects and General => How do I?? => Topic started by: Barefoot-Leather on September 08, 2009, 07:52:19 PM
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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
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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
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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
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Hmmm...it is small, it is broken, you have the pieces and it is cast iron. Is there any prospect of casting another?
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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
(http://i998.photobucket.com/albums/af103/Barefootleather/Leatherwork%20Machines/riveter-top.jpg)
(http://i998.photobucket.com/albums/af103/Barefootleather/Leatherwork%20Machines/the-broken-bit.jpg)
(http://i998.photobucket.com/albums/af103/Barefootleather/Leatherwork%20Machines/Riveter-3.jpg)
(http://i998.photobucket.com/albums/af103/Barefootleather/Leatherwork%20Machines/Riveter-2.jpg)
(http://i998.photobucket.com/albums/af103/Barefootleather/Leatherwork%20Machines/Riveter-1.jpg)
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Now we can see the problem, I will now tell you adhesive will not work. Because of the rough faces being bolted together, there would be just too much stress put on the joint for it to hold.
That really is a bronze welding job. Unfortunately I don't have the equipment any more, but if you could approach a training college, I did my two years of advanced welding at Shrewsbury Tech College (if it is still there), not too far from where you live. I am sure they could fit you in on an evening class and do the job for you, giving the pupils a bit of practice. Would be very cheap as well.
Otherwise you would have to find a workshop which has the oxy/acet facilities to get the job done. It could be stick welded, but it would again mean finding a specialist to do it for you.
Sorry I can't be of any more help.
Bogs
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Ray
Will do some scannin' n snippin' for you.
I'll also look for some in 'Stationary Engine' mag.
Probably some in there, SE afflictionados usually get cracked castings.
Have to go out now, so will be circa 6PM
Dave BC
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www.mig-welding.co.uk/forum/showthread.php?t=5762 -
cgi.ebay.co.uk/Cast-Iron-Welding-Rods.-5-x-Esab.-Cold-Weld-Cast-repair_W0QQitemZ140341968134QQcmdZViewItemQQimsxZ200...
www.ehow.com/how_5017583_weld-cast-iron-cracking.html -
Just some of many sites giving details of ''cold weld'' techniques for repairing breaks in cast iron, as to whether it is as popular now as it was 30 odd years ago remains to be seen...then whilst on holiday in southern Ireland a cast iron gear in our hosts reaper broke in two and he was in a real tizzy as to how to get his harvest in, I asked him to find an electric welding rig and some ''cold weld rods for cast iron which he duly found, after giving the broken gear a good chamfer and clean up I welded it together, tidied it up and it was reinstalled in the reaper...he got his harvest in and I got 50% off my holiday costs.
John.
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Ray, I really do not know how much casting costs but it might be worth taking those pieces to a foundry for an opinion. It seems to me that the dimensions are not critical (thinking of shrinkage etc) and there is only one machined surface.
However, if it was mine and I was looking for a practical fix rather than a perfect restoration I would drill two holes in a piece of rectangular bar, find some longer bolts and put it over the two pieces to clamp it all up tight, but then I am somewhat of a 'bodger'. ::)
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I can weld that no problems.
John S.
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I was willing to bet that JS could fix that. :bow:
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During a short walk along the Montgomery Canal today SWMBO and I encountered a blacksmith working in his forge. A very nice chap who invited us in and answered questions.
He was restoring some railings for a project funded by CADW, a Welsh heritage trust. This involved arc welding cast iron with expensive rods. Probably not quite what you had in mind, but maybe worth a try.
William O'Brien
Artist Blacksmith
The Wharf
Berriew
Nr Welshpool
Powys
SY21 8AN
(01686) 640739
willob1@btinternet.com
www.wobrien.co.uk
No connection with him, just met him today
Ray
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Wow Ray
Thats some fantastic Blacksmith work thanks for showing.
Have fun
Stew
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Thanks - He is a much better blacksmith than he is a webpage designer. Picture file sizes are huge so it's a lot slower than needs be.
He's got some wonderful tooling including big hammers. One he uses has a 2hp motor and he's refurbing an overcrank Massey. Might have a pic of that but not yet.
I live only a few minutes upstream on the Severn from him. I'll probably make a nuisance of myself.
Ray
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I am no welder but had cast iron Ford RS track control arms cut and welded at work some years back. Joints were V out preheated with oxy acet and different rods, wrapped in rags and left to cool very slowly. Fair bit of stress there.
Ray best bet not far away from you is above link in Powys and can use forge as it cools down to anneal.
Regularly use a forge at work and that would take some heating up.
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just an idea
Would it not be possible to cut of the piece of CI horizontal and bolt a piece of mild steel on from the bottom -from the pics there seems to be enough material. This would not be the idea restoration but would be strong enough to last.???
Gerhard
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Our local welder no longer welds, fixing things, his true calling is in an art form, he also works in acrylics to do preliminary designs for his projects. http://www.steelisalive.com His medium is othr peoples castoffs and throwaways, some folks call it junk. "One mans trash is another mans treasure"
Cliff
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Cast iron can be easily welded. It requires pre heating and a high nickel rod but any competent welder should be able to do it.