turbo exhaust manifold welding cast iron

[pete1]

So this is fairly off topic, but thought someone can help me.

Need someone to weld up a cast iron turbo exhaust manifold and wondering if someone new someone or workshop in Vic that could do it for price.
Emailed a few places got no reply or a reply that says they don't repair cast iron.I thought about doing it myself, but limited experience with cast iron, I'm worried a bit of the weld may break off and go into the turbo.
Replacement wasn't cheap and if it's cheaper to fix, might aswell.

Thanks pete1

[valkyrie]

If you arent sure about your welding weld a larger patch on the outside of the hole/crakc that wont fit through the hole. That way it can only go out away from your turbo

[happyhunter]

Years ago I tried to weld the cast iron manifold on my HX Holden with a MIG and it was no go. So I pre-heated the weld area with an OXY flame before welding the crack with the MIG and it welded up perfectly.

[Chronos]

Yep, the key with cast is to make sure it's clean including removing any rust and carbon then preheat over 150deg then just weld on a patch. Stainless steel has similar expansion/shrinkage rates to cast steel so it's common to use stainless electrodes on cast.

Chronos

[Die Judicii]

Chronos ol mate,,,, there is a big difference btween cast iron and cast steel.

As for general repair work/welding of cast iron,, every piece of cast iron is different to the last or the next.
As we have no control whatsoever over the mixes that are poured, therefore it can require experimentation to find which particular electrode ( and I refer to the MMA process ) to use, and there are a myriad of rods/brands to choose from.

When one in particular gives best result, then you need to work out whether to pre heat, and keep a constant temp throughout the process,,,,, or,,,,,,, go the cold weld method which involves keeping the entire repair area to a minimum temp.
Usually when going the cold method you must be able to place a bare hand on the area without being burnt.
Soon as it gets above that range, you must keep the job in a draft free area, and walk away till the temp drops to an acceptable level.

Either the hot or cold method is usually done best in short/heavy runs with peening of the deposit in between.

If going the hot method, post heating evenly is just as important as pre heating.
Also after post heating, bury the job in a container/bag of lime powder for at least 6 - 12 hours.

Your choice of electrode will also be governed by whether or not you need the repaired area to be machined or drilled afterwards.

The above is only a very brief few of many many rules and techniques that can or will need to be applied.

Also, if grinding for preparation, do NOT grind to a sharp edge anywhere, always keep smooth rounded edges.

After grinding,,, the entire surface that has been ground MUST be filed clean with a coarse file to get rid of the precipitated carbide deposits caused by grinding.
If you weld over carbide surfaces, they will create incredibly hard spots and also induce cracks.

Having done cast iron repairs for many years, I can almost guarantee that any business that does this sort of work would never give a quote on cast iron repairs sight unseen,,,,, let alone give a guarantee on the repair.

Hope some of the above is helpful,,,,,, (PM coming your way)

[duncan61]

I held a code in pipe and always knew cast Iron was an special job.It can be done but beyond my ability

[straightshooter]

So this is fairly off topic, but thought someone can help me.

Need someone to weld up a cast iron turbo exhaust manifold and wondering if someone new someone or workshop in Vic that could do it for price.
Emailed a few places got no reply or a reply that says they don't repair cast iron.I thought about doing it myself, but limited experience with cast iron, I'm worried a bit of the weld may break off and go into the turbo.
Replacement wasn't cheap and if it's cheaper to fix, might aswell.

Thanks pete1

When you say 'weld up' what exactly do you mean?
Is the manifold cracked or broken and in need of repair?
Is it that you want to modify an existing manifold? If so how extensive are the required mods?
Unfortunately, on most forums, simple naive questions usually get simple naive answers.

[pete1]

So thanks guys for the replys, I've been working flat out so not much free time so I'll put some pictures up to show the problem better.

[pete1]

Here it is off car on bench.

DSC_0172.JPG (649.45 KiB) Viewed 7650 times

DSC_0170.JPG (612.45 KiB) Viewed 7650 times

DSC_0171.JPG (523.57 KiB) Viewed 7650 times

[Die Judicii]

From the look of those pics, My thoughts would be that it is certainly not impossible but ,,,,,,,,,,,,

a) the cast surfaces to be welded are "burnt", and that just presents more headaches.
b) the cracks are very extensive to the naked eye, and would actually extend even further than you can see.
c) in welding it you are very prone to start more cracks due to expansion and contraction.
d) being what it is, if welded, I wouldn't be able to relax cos I'd be waiting for it to crack again alongside or elsewhere in the housing, and the possible resultant damage would likely exceed the cost of a replacement turbo.
e) maybe look into a 2nd hand one if you can't afford a new one at the moment.

f) if you are hell bent on repairing this one, find someone that has and can operate one of those Eutectic Castolin flame units with the powder feed hopper.
One of those is the only method that I would recommend for this job,,, that would be a reliable repair.

Cheers,,,,

[pete1]

From the look of those pics, My thoughts would be that it is certainly not impossible but ,,,,,,,,,,,,

a) the cast surfaces to be welded are "burnt", and that just presents more headaches.
b) the cracks are very extensive to the naked eye, and would actually extend even further than you can see.
c) in welding it you are very prone to start more cracks due to expansion and contraction.
d) being what it is, if welded, I wouldn't be able to relax cos I'd be waiting for it to crack again alongside or elsewhere in the housing, and the possible resultant damage would likely exceed the cost of a replacement turbo.
e) maybe look into a 2nd hand one if you can't afford a new one at the moment.

f) if you are hell bent on repairing this one, find someone that has and can operate one of those Eutectic Castolin flame units with the powder feed hopper.
One of those is the only method that I would recommend for this job,,, that would be a reliable repair.

Cheers,,,,

Thanks for the info i think its better to replace it and take 5 seconds to do.
Might practice welding cast iron and chuck it in the scrap metal pile when i'm done.
Thanks mate

[Die Judicii]

No worries,, mate
Glad to be able to impart a little bit of info.

[Ricochet]

Pre heat, a few people have mentioned, but slow cool is the other side of it. If you can place the piece in hot vermiculite, hot ashes or let it cool down in a kiln or kitchen or toaster oven you will have better chances of avoiding cracks.

[Oldbloke]

I remember an old welder used to weld this type of thing including engine heads and blocks all the time.

he spent a lot of time preparing the weld for example grinding out a nice deep V.
He would then put in a furnace and very slowly heat up over a few hours but I don't recall what temperature. He welded using the correct rods and there were several types of cast iron rods is selected from. He then bury it in the furnace in sand and leave it the cool overnight and I recall he considered that to be a very important part of the process by the way.

He used an arc welder

this is just from memory and was over 40 years ago r

[Member-Deleted]

G'day pete1 mate you can do all the practice in the world but if the cast will not take weld of any sort then it's impossible DJ has hit the nail on the head . I have fixed many manifolds and nearly every one was tolerant to different metals the only way I have found is spray welding it's where you groove the crack out and thoroughly clean 1''( if possible) either side of the crack., do this with a grinder or emery pad that fits onto a grinder then heat to red hot just breaking white hot in this area the powder container is screwed to a special oxy-acetylene adapter ( a bit like a cutting torch) NOTE these metal powders come in plastic bottles about half the size of a cup, ''AND EXPENSIVE'' now when the job's up to heat requirement then touch the lever on the torch the powder will drop into the flame and merge with the manifold providing it's hot enough , you can tell this by the roughness of the weld spot and non flow ,then it's just keep building it up until it's slightly over the diameter of the parent weld metal .It then has to be cooled in lime over 12hrs or more I left it till next day to be sure.You will have to get someone who does this type of welding and has the gear to do so it's called spray welding and i.ve had exceptional success with it for manifolds and building up worn shalves ready for machining . now on saying this your manifold looks old and been broken for some time and this could be a problem in itself but that's the only way i'd attack it mate good luck.

[Member-Deleted]

Yes OB that's about how it went. Most of those cast irons were fairly easy to weld if you stuck to the procedure but todays cast is totally different in most cases. a lot of the old cast also could be braised with oxy and brass rod with flux, but most of todays cast won't take the brass even with flux. they are making it harder and less tolerable to welding . the reason being it's cheaper to make more carbon less iron = hardness . there's a classic I used to get often and that was Bed ends, the lugs used to break off or crack I never worked out a way they could be welded , it just wouldn't weld and when it did the next day i'd find it cracked again so I stopped even trying

[wrenchman]

did you fix the reason that it crack if not it will crack again.
there is lot of prep and time to weld cast my late brother did it .

[pomemax]

What weld cast iron easy as just use a STAINLESS steel rod I have done that a few time works ok.
Just clean your start point for the weld pool and weld downhand is best same rules as stainless if you send the bead blue it to hot drop your amps.
No pre heating no cooling down best with a touch rod say Stanicraft and a close arc.

[flutch]

Yep, the key with cast is to make sure it's clean including removing any rust and carbon then preheat over 150deg then just weld on a patch. Stainless steel has similar expansion/shrinkage rates to cast steel so it's common to use stainless electrodes on cast.

Chronos

THIS, welding non like metals is always finniky with heat, you really do need to make sure that whatever wire/rod you use is not going to expand or contract at vastly different rates than the parent metal. remembering that exhaust manifolds on diesels can get gasses in excess of 700 degrees when under heavy load. this makes a big difference, also heating up/cooling down, creek crossings, and driving into hail/rain and all that crud can have an effect too and over time, do as chronos says and will be your best bet, that or have a new manifold fabricated that doesn't have that hole/crack on it.

[flutch]

Chronos ol mate,,,, there is a big difference btween cast iron and cast steel.

As for general repair work/welding of cast iron,, every piece of cast iron is different to the last or the next.
As we have no control whatsoever over the mixes that are poured, therefore it can require experimentation to find which particular electrode ( and I refer to the MMA process ) to use, and there are a myriad of rods/brands to choose from.

When one in particular gives best result, then you need to work out whether to pre heat, and keep a constant temp throughout the process,,,,, or,,,,,,, go the cold weld method which involves keeping the entire repair area to a minimum temp.
Usually when going the cold method you must be able to place a bare hand on the area without being burnt.
Soon as it gets above that range, you must keep the job in a draft free area, and walk away till the temp drops to an acceptable level.

Either the hot or cold method is usually done best in short/heavy runs with peening of the deposit in between.

If going the hot method, post heating evenly is just as important as pre heating.
Also after post heating, bury the job in a container/bag of lime powder for at least 6 - 12 hours.

Your choice of electrode will also be governed by whether or not you need the repaired area to be machined or drilled afterwards.

The above is only a very brief few of many many rules and techniques that can or will need to be applied.

Also, if grinding for preparation, do NOT grind to a sharp edge anywhere, always keep smooth rounded edges.

After grinding,,, the entire surface that has been ground MUST be filed clean with a coarse file to get rid of the precipitated carbide deposits caused by grinding.
If you weld over carbide surfaces, they will create incredibly hard spots and also induce cracks.

Having done cast iron repairs for many years, I can almost guarantee that any business that does this sort of work would never give a quote on cast iron repairs sight unseen,,,,, let alone give a guarantee on the repair.

Hope some of the above is helpful,,,,,, (PM coming your way)

+1000 my advice is get a new manifold fabricated haha...

[Die Judicii]

Pomemax,,,,

I made mention early in this thread about finding some-one with the "Eutectic Castolin Powder Spray welding torch.
This method (although expensive) is tried and true and is the nearest thing yet to getting a perfect weld and reliable repair on cast iron manifolds etc.

Take it from a couple of old blokes that have both had extensive experience in the maintenance welding field,, and still have fingers in the pie.
I myself used it day after day for years when full time employed in the industry.

The practice of welding cast iron with stainless based electrodes or with a MIG is a process that may appear successful, and can suffice when proper
methods aren't available,,,, but are usually fraught with inherent problems, the most common being extremely hard and brittle deposits and carbide precipitation which will sooner or later cause failure.

[pomemax]

As you say Die Judicii
When proper methods aren,t available , most guys just want it fixed tho and I bet after the 4 years since this post was first posted hes found a solution.
Eutectic Castolin Powder Spray welding torch I have used it quite a bit so I know what your saying think I still have a set up in the works shop not had a calling to use it in the last few years .
Extensive experience in the maintenance, welding field tell me more myself I am a fitter machinist / welder whos worked for the last 47 years in this feild I may know you

[Member-Deleted]

Ahh there you go 4yrs , see that's a good forum, you can learn a lot from other people over a long period of time .

[Die Judicii]

Extensive experience in the maintenance, welding field tell me more myself I am a fitter machinist / welder whos worked for the last 47 years in this feild I may know you

Unless you've been doing new boiler installations and or boiler repairs,,, or worked in Adelaide on the Collins Class submarines,,,
I 'd say our paths have never crossed in this particular field.

[pomemax]

boiler installations and or boiler repairs in Sydney for a few years the last of the grey funnel line ships I worked on was fitting a prop to an aircraft carrier in sydney many many years ago .

[John]

Cast can be welded with a stick welder and the correct rods for the job available at any industry supply’s store BOC gas weld all weld to name a few.
It can be a little hard but with the preparation done right not that hard

First clean the area really well I’d use a dremal to get in to the crack open it up a little to take the weld.
Now your gunna need to send the misses out for the day bit hard at the moment

Turn on the oven set it to 100 degrees put the manifold in the oven from cold and let it slowly heat up to the hundred mark it will take a few hours as cast tends to heat unevenly

Once pre heated weld up the crack be for it cools out don’t turn the oven off

Put it back in the hot oven leave for an hour and a half than turn down 20 degrees for an hour and keep turning down 20 degrees every hour until your at the lowest temp setting

Turn the oven off and leave don’t open it let it slowly cool to room temperature generally takes a few hours

And fingers crossed job done

But it’s not the 100% way of doing it but as good as it get at home and should do the job for
Ps I generally pre heat the welding rods at the same time in the oven

If it want fit in the oven preheat with a flame weld and cover with lime to control cooling if your in a bind sometimes it does work I’ve had to do that with larger things made from cast.
All the best hope it works out for you that’s how I’d attack it coming from my experience in the metals trade as a boilermaker