"Mike wrote:

What kind of welding equipment is available to you; Stick, Mig, Tig, OxyActy.

Is your case cast steel or cast iron.

You need to drill holes at the end of the crack before you weld to keep it from cracking further as part of your prep.

When that crack gets hot, your gear oil is likely to thin and get into your weld, contaminating the weld. One trick to minimize this is to apply vacuum to the case so that air enters the case from the outside moving the oil away from the weld.

Just a few things to think about before you choose a filler metal.

That sucks. If your case is cast iron it may not be repairable due to its physical size. Better to follow AJ's advice and find someone who has successfully done this before. Preheating that crack is likely to make the cast on either side of the crack harder, ensuring it will crack again. There's all sorts of people selling magic rod and methods to weld cast. Take AJ's advice and find a local welder who has done this sort of repair successfully to someone else's machine. There are no short cuts. My experience is in gas welding small cast parts which is not going to help you here.

That is a job for an experienced welder for it to have any chance of success,that housing is cast iron and it welds very badly,you would need to find the reason for the crack,is it damage from hitting something,or is there something loose causing slap,it is an unusal place for a crack to appear,I have not seen it before,there are a couple of pictures from the manual of whats inside there.
Good luck
AJ

What kind of welding equipment is available to you; Stick, Mig, Tig, OxyActy.

Is your case cast steel or cast iron.

You need to drill holes at the end of the crack before you weld to keep it from cracking further as part of your prep.

When that crack gets hot, your gear oil is likely to thin and get into your weld, contaminating the weld. One trick to minimize this is to apply vacuum to the case so that air enters the case from the outside moving the oil away from the weld.

Just a few things to think about before you choose a filler metal.

I have been following thread, Welding Cast Iron Manifolds isnt too good, but possible. Best to pre heat pieces in oven, or firebricked forges with gas touch, elec oven is more controlled, get parts to about 400 oC, have the joint preped out at 45, and use brasing rod filler to join, then stick the welded part in dryed sand (foundry sand) and leave for 12 hours .

Ref Manchining for Gasket Face, I just use the same method, used engineering Sub Contact Companies. Milling Machine, as used in high volume production. Its all about Surface Finish, you need slight groves in the surface to grip the gasket tight. A milled Finish with a 0.003" depth of cut,a Pointy tip type 1/64 rad on tip and a get the feed up, like a roughing cut, or a Planer finish is idea also. same as cylinder bores, get um too smooth and your rings will never bed in . all my drawings for cast iron houising, mainly call for gasket face finish. Or use a Surface Grinder Ring Grinder, gets it flat and a rough Finish, similar to a Lumbsden Grinder.

Adding a View from the North

Catman

I was always told that if the "insulating" material (sand, lime or ashes) was heated and dry is the best as it promotes slow cooling relieving stress in the material.
All I can say is that I have welded or brazed various Cast Iron pieces in the 38 years of "home school" welding and found the best one is to preheat them to various temperatures dictated by the age and quality of the Iron. Weld, peen, then cool SLOWLY over as long of a period as patience allows. I have found that a Gas Grill works the best for an "oven" because you can preheat as long as you want, then post cool while reducing temperature over a long period of time. This also boils the oil out of a piece which promotes better welds.
Just don't do it on Steak Day!
Jeff

I'll have to chip in and agree with Stephen. Over the last 40+ years, when I've worked on cast iron I do one of two things; 1. keep it cool enough that I can lay my hand on it after peening between passes or 2. preheat, do the weld(s) and as soon as I'm finished, bury it in sand or wood ashes for a day or so 'til it's completely cooled. I've used several methods for welding cast, Ni Rod electrodes or something equivalent or a cast iron stick and oxy-acetylene to fusion weld. The cast iron stick and oxy-acetylene is old school and not often done anymore but it will leave an almost perfect color and strength match.

If there's any machine work to be done to the chunk, quenching it will make it harder than the hubs of Hades. Slow cooling will allow machine work to take place as it doesn't harden the material. Ni Rod 99 will allow machining after welding, Ni Rod 66 with it's lower nickel content leaves a really hard section right at the weld/ parent metal interface and is not recommended for machining.

I would use the title "Progess on Ernie" but today was one step foward and two steps back. First, thank all of you for educating me on cast iron welding. I actully fell like I have some experience now. Today's effort involved removing the heat box mounting stud that I broke when dissembling. I had it soaked in Kroil and I gave it some heat to help. I found out the hard way that the outer portion on the intake manifold, that contains the exhaust gases around the inner intake manifold, is only about .020 thick. And yes I cracked it. Fortunately for me, John from Fresno has found a ceramic paste called Fire Seal 2000, made by POR 15, that once cured will take 2000 degees. JB Weld is only good for 500. The initial problem with the wear/rust spot can be easily fixed if this product does what it claims. It says it was made for repairing exhaust manifolds. At the rate I am going I probably should have ordered 2 tubes of the stuff. I will do a product review on this thread when I get the job done. Thanks, Gary


www.por15.com/FIRE-SEAL-2000/productinfo/FS2/

On something like manifold I use railroad rod{ is cast iron in stick form] [may be hard to find these days] requires a good flux for welding problem cast-use torch same as brazing- but cast is easier to flow/ build/ shape while melted/ preheat & slow cool down.will machine & look like original iron..

I have welded up exhaust manifolds and heat boxes before using my mig welder with mild steel wire. The same precautions apply. Clean the metal well first. When welding cold, don't let the manifold get any hotter than you can comfortably hold your hand on. Another problem about welding cast iron with mild steel wire is that the weld is not machineable after welding. The combination of cast iron and mild steel makes a weld as hard as cobalt steel. You can grind it down, but don't try putting machine tooling to it. Another thing is that mild steel oxidizes in the heat faster than the cast iron does. For a weld job that will last for years and years, mild steal will not take the heat of an exhaust manifold very well. It will rust out before the cast iron will.

i like to weld cast with 7018AC. for an exhaust manifold you will need to use a nickel
rod for cast iron. used exhaust manifolds are difficult to weld, 7018 will not apply. the
only rod i have gotten to work is a cast nickel. luckly you are not in need of strenght.
heat to around 400/500 degrees and weld. weld an inch or so and take your chipping
hammer and peck the area you welded and the rest of the manifold for 30 seconds or
so. weld again and peck, weld again and peck. this works really well to relieve the
stresses that occur in the welding process. as the piece is cooling after you are done
welding continue to peck at the manifold untill it cools to a level you can lay your hand
on. let it cool naturally while pecking on occasion. if you do not peck, you may hear a
loud pop, that being a new crack. do not forget to grind or clean the area to be welded.

This is a progress report and request for advice on Ernie, a PV 15. We last left this restoration project with Ernie only running for 5 or 6 seconds before he would quit. It appeared that there was alot of smoke coming from the exhaust manifold other than out the outlet pipe. I decided to take apart the exhaust/intake/heatbox assembly to check for sealing of all surfaces. The main gasket looked tired but I did not notice any intake leaks on the two ports. The heat box gaskets were basically non existant and obviously not sealing. On the intake manifold, the sealing lip closest to the block for the heatbox, there was a slight depression from rust/wear and I think this is where the major leak is. It looks like this area should be welded to raise it up so I can get a flat surface. This depression is about .030 to .040 inches deep. My question today is on this thin lip, what is the best welding rod to fix this and how hot shoud the cast iron be preheated before the welding begins? Thanks again, Gary

Often on these old critters they used high strength bolts and studs. You can drill 'em as long as you use a low speed and heavy feed but drill all the way through. When you heat 'em and then later try to drill 'em, you'll find you've tempered 'em to about the hardness of diamonds. Unless you then use a carbide drill bit, you're not gonna get anywhere with 'em. Go straight to welding nuts on at that point. I use a mix of 2 stroke oil and acetone and start soaking 'em as they cool. (Gonna hafta try the candle trick sometime.)

I start with drilling the offending bolts/studs all the way through, then soak 'em with "loose juice". An easy out is next and if/when that doesn't work I start welding slightly oversized nuts on. Let cool slightly and more "loose juice" then give 'em a whack with a 5 lb hammer after they've cooled and usually, out they come. Sometimes I've had to weld a nut on more than once.

I've burned a few out after drilling 'em but I reserve that for 1/2" stuff and up. Heat 'em up til they spark, pull the torch back and hit the oxy lever. A really clean tip is needed and a steady hand as well. After the thing has cooled, usually a file tang will twist 'em out. . .as long as you didn't burn into the threads in the cast iron.

I know just what you're talking about, my D2 manifold is in probably about the same shape as yours. Exhaust Manifold bolts seem to be the worst, due to all the heating & cooling over the years they can fuse together and pretty much become part of the manifold. Don't expect them to come out easily. Vice Grips & easy-outs will just make the bolts mad. You will most likely need to break out some big-boy tools and just declare War on the #@&?!(^%)?! bolts.

When I restored my Jeep there were a lot of broken bolts in the frame, most with little to grip on and none of them would budge. I tried welding nuts onto what was left of the bolts but they would just break off. The best method I found was to just keep adding weld onto the broken bolts a little at a time until you have a decent size blob to grip on (that will also put a LOT more heat directly into the threads). Let it cool off a bit then use a small pipe wrench to unscrew the bolt. It works great!

Another method I have used on Cast Iron is to blow the bolts out with a cutting torch (ah, the old Fire Wrench). If you're careful and with a little practice you can burn the steel bolt out of cast iron and not harm the cast iron. The steel will melt & puddle long before the iron. Clean the threads out with a tap and you're good to go.

955 12A Traxcavator Hi-Performance Exhaust Manifold

You gotta love this work of art…
When I bought this Track Loader it had a stainless steel exhaust manifold in place. The owner before me built this using sanitary food grade fittings. It’s actually a very good job of welding and fabricating. My guess is this will last forever. The previous owner said the original manifold developed a leak.
My question…
did the original cast iron manifolds on these machines often go bad / deteriorate? Or is this indicative of a tractor with a LOT of hours on it? (the hour meter is not working).

I'm with Gauntjoh on this one (by the way it was good to meet you John at
the agm at Russel Saywell's), some years ago I built up a final drive pinion
on a Twenty Two using high tensile electrodes if I remember correctly,
most gears are either machined from blanks or cast steel, some old
implement gears are cast iron, the cast iron gears will be harder to repair
due to cooling of the weld and the quality of the cast!

as for repairing poney motor blocks I'd use nickel rods,
general rule is only weld 10x diameter of the rod, ie 2mm rod weld
length 20mm and peen the weld with a ball pain hammer as it cools
gently preheat the block before welding,

shovel man.