Winch repair (Cast).

[F.J.]

Not sure if this is in the right section but I need advice on how to tackle this repair.

It is a winch and the top motor has been hit and snapped off. It is 1/2" cast and having done very little cast welding im a bit unclear of which way to approach it! Would TIG be best suited and if so, ive heard of dissimilar filler being used but also 309 stainless? Also, Would you pre heat/post heat?

Thanks

 

[Kent]

what happens if it fails? It might want to be something you pass on perhaps? cheap repair against big liability? the issue is what's its true metallurgy but remember it was likely a lot stronger before it failed than you can make it by welding with any consumable or process
even if the winched item just stops moving in the event it fails I think personally I might pass

 

[wyn]

Is there a seperate brake? If the motor is the only thing that holds it then, as Kent says, there could be some nasty liability issues if it lets go again.

 

[WorkshopChris]

I have done something similar in the past. welding cast is normally hit and miss. But if the part is motor drive only with the braking taken care off somewhere else, then bore both internal parts and sleeve once parts are aligned drill and pin then vee out and braze. pre and post heat then wrap in old fire blankets to cool. Depending on how well the cast cleans up it might want a pre / post heat cycle first before any brazing or welding as the cast can sometimes absorb the oil and grease and it almost sweats oils out once heated even when it looks spotless.

 

[Kent]

We're I really learnt my trade we did lots of this stuff
Honestly I wouldn't have think this might be taken on
Even if it's breaked you might be left dangling on a wire literally
You won't even get what your excess is and a big claim finishes most firms

 

[Richard.]

Is that cast iron?
If so cut your losses. Ive weld repaired cast iron a few times with the mind set that it will last as long as it lasts. You cannot approach that with the same mind set. You can get Ni based electrodes which are for such things but it's a risk and there is a lot more steps to a good cast iron repair than just welding. Stainless filler is about the worst thing you can use for it. I don't reccommend you do it. I wouldn't do it and I have welded a fair bit but because you've asked you would defo need a good preheat say 200 C and soak it through out the whole thing not localised. You then weld an inch or so then stop and peen the weld while it's hot to stress relieve it then weld then peen etc. you then should rap it up and monitor its temp as it drops. Don't let it drop quickly or it will fail. Slow cooling is the most critical part.
But.................. DONT WELD IT IMO.

 

[daleyd]

I'm no welder so I'll bow to the much superior knowledge of Kent and Richard above, but if that's lifting anything substantial (TBH even if it wasn't, the lump itself looks heavy enough to hurt if it were to fall)I wouldn't touch it with a bargepole. Even if it is just a winch for a LandRover or something - if it was to fail and the vehicle rolled back on to someone...

 

[TechnicAl]

Assuming that it is cast iron. Many (in fact most) castings like that will be SG Iron which is reasonably weldable
A joint done well using NiFe stick electrodes will be stronger than the cast iron..........cast iron is good in compression but not so good in tensile or shear

Firstly though what caused it to break in the first place. Was it an accident of some description or did it just fail in service? If it was in service what caused it. Can you see where the crack started....is there a shiny section where the faces have rubbed prior to complete failure etc etc etc

I cant really see the fractured faces well enough and its not easy from photos anyway.

I know Im bucking the trend a bit but I would say that a repair is possible if you go about it the right way. I would take it to a specialist or at least someone who has some experience of cast iron welding and at least discuss it with them. If a replacement part is available it might be cheaper to go that way. Stitching could be another possibility

You cant beat face to face discussion

 

[winchman]

What make is it as bits may be available?
Personally if its welded it may well fail when you least expect it

 

[Migmac]

We have winches, they get inspected yearly. Any broken ones get binned, unless the broken bits can be replaced. I've worked tractor mounted winches and when they fail it is spectacular and very dangerous. In my humble opinion I wouldn't repair that one, it's not worth the possible grief

 

[winchman]

We have winches, they get inspected yearly. Any broken ones get binned, unless the broken bits can be replaced. I've worked tractor mounted winches and when they fail it is spectacular and very dangerous. In my humble opinion I wouldn't repair that one, it's not worth the possible grief

Excellent advice
Let me know what make it is and I will have a dig around

 

[Screwdriver]

I doubt if you would be able to affect a simple repair just by sticking the old bit back on. The part will not be as strong as the original piece which itself wasn't strong enough.

If you have to reuse that winch, I'd be looking for a solution to upgrade that connection. I'd manufacture a new part which can be firmly attached to the main body incorporating a new flange. You would need to machine off any broken parts of the casting, fabricate a repair piece which incorporates the flange and have it "wrap around" the winch body so that you can secure it in several places either with fixings or by welding.

S.

 

[Chris Stevens]

Not sure if this is in the right section but I need advice on how to tackle this repair.

It is a winch and the top motor has been hit and snapped off. It is 1/2" cast and having done very little cast welding im a bit unclear of which way to approach it! Would TIG be best suited and if so, ive heard of dissimilar filler being used but also 309 stainless? Also, Would you pre heat/post heat?

Thanks

If its aluminium then dismantle, clamp the 2 parts together with as much pressure as feasible. Then get 4 good tack welds, around the break. After tack welding vee the areas between the tacks, and gradually fill the vees with weld being careful to avoid distortion. I have many repairing cast parts over many years, and find 5556 is sometimes more effective than 4043 filler, if weld strength is crucially important. Its easily repairable, but I would want to find out the reason its failed, before making any attempt at making a repair.......................

 

[CompoSimmonite]

When I had a broken casting (motor mount for lathe) the lecturer at college said better to start again with a new casting. He told me to glue the broken parts together with reinforcing pins into drilled holes as necessary then take to a casting company and get them to use it as a pattern to make a new item.

 

[Chris Stevens]

When I had a broken casting (motor mount for lathe) the lecturer at college said better to start again with a new casting. He told me to glue the broken parts together with reinforcing pins into drilled holes as necessary then take to a casting company and get them to use it as a pattern to make a new item.

Bet he wasnt paying for it, and wasnt without a lathe while foundry made a new one?

 

[Kent]

Assuming that it is cast iron. Many (in fact most) castings like that will be SG Iron which is reasonably weldable
A joint done well using NiFe stick electrodes will be stronger than the cast iron..........cast iron is good in compression but not so good in tensile or shear

Firstly though what caused it to break in the first place. Was it an accident of some description or did it just fail in service? If it was in service what caused it. Can you see where the crack started....is there a shiny section where the faces have rubbed prior to complete failure etc etc etc

I cant really see the fractured faces well enough and its not easy from photos anyway.

I know Im bucking the trend a bit but I would say that a repair is possible if you go about it the right way. I would take it to a specialist or at least someone who has some experience of cast iron welding and at least discuss it with them. If a replacement part is available it might be cheaper to go that way. Stitching could be another possibility

You cant beat face to face discussion

stitching, as in them pin/plate things that hammer in? I thought they were just for stopping cracks in a casting still in one piece?

 

[TechnicAl]

stitching, as in them pin/plate things that hammer in? I thought they were just for stopping cracks in a casting still in one piece?

https://www.metalock.co.uk/typical-on-site-repairs/metal-stitching.aspx

 

[F.J.]

Thanks for all the info guys, I spoke with my welding rep this morning and he told me everything you guys have said, I don't like shying away from jobs, but having said that I am dubious about this one. I've since spoke to my customer who has decided to buy a new winch but still wants me to repair this one which I may do as I now have more time to do my homework.

I'm not sure of the make but will do as soon as it turns up so will let you know as and when @winchman thanks.

The nickel rods are £70 for 1kg pack so if I do take it on I'm going to have be sure I'm confident enough it'll be right afterwards. He initially thought he could bring it in and I would 'smash a weld in it' as he put it but once I told him how long it would take he bought a new one as he had already had to turn down 2jobs due to this winch being broken

 

[brightspark]

people have this notion that u just weld it up they don't think u have to strip it all down and seals and bearings will be ruined if u don't and the job could take a full day or longer

 

[Kent]

https://www.metalock.co.uk/typical-on-site-repairs/metal-stitching.aspx

A little wiser now. I still don't think its something I might ever try for a fully separated cast component. It just seems wrong to spend so much time on what seems to still be an emergency bodge up in my mind at least