what to use welding a exhaust manifold

[marlin54]

I want to weld my exhaust manifold that broke in half. . after grinding it clean I want to know what rod I can use and is there any other way to fix it or something to use other than welding rod . its a manifold off a case 580 backhoe. what is the metal ? cast steel or cast iron? do they make a patch material ? I once weld my exhaust with brass rod and it finally got so hot on a long trip it melted and fell apart. what can I use ? thanks

 

[Jim.ME]

I believe it is a grade of cast iron. There are special filler metal rods you can use to gas weld (like brazing) cast iron. Or there are a number of specialty electrodes for arc welding. Your local welding supply house should be able to help you find the right one to use with the welding equipment you have. You will need to pre heat it and have post weld cool down controlled to be slow. As far as patch material I have known of people breaking up old manifolds to get patch material.

I hope it works out for you. In my experience exhaust manifold welding does not have a very good success rate due to the contamination in the material, as well as the heating and cooling cycles the material has been subjected to previously and will be in the future. Is there a reason you don't want to purchase one of the aftermarket exhaust manifolds available, since it doesn't look like you've had many responses on a used one? Just curious.

 

[Steve@Advance]

That is a job best left for the pros, and unless this is a "have to" situation, you will be much better off buying a new manifold, or a good used one.

Problem is, there won't be much left to weld. The remaining iron will be oxidized and thin. Thermal cycling will take it's toll, chances are it will break again shortly.

If you do decide to try, be sure to weld as much as you can with it bolted to the head or bolted/clamped down to a known flat surface. Nickle rod is the usual choice.

 

[David G]

The probability of successfully welding an exhaust manifold is pretty slim, it is cast iron and expands/shrinks a lot.

 

[rustyfarmall]

(quoted from post at 07:39:14 02/04/20) That is a job best left for the pros, and unless this is a "have to" situation, you will be much better off buying a new manifold, or a good used one.

Problem is, there won't be much left to weld. The remaining iron will be oxidized and thin. Thermal cycling will take it's toll, chances are it will break again shortly.

If you do decide to try, be sure to weld as much as you can with it bolted to the head or bolted/clamped down to a known flat surface. Nickle rod is the usual choice.

I second the motion to bolt it to the head and then welding.

 

[buickanddeere]

(quoted from post at 09:36:50 02/04/20) I want to weld my exhaust manifold that broke in half. . after grinding it clean I want to know what rod I can use and is there any other way to fix it or something to use other than welding rod . its a manifold off a case 580 backhoe. what is the metal ? cast steel or cast iron? do they make a patch material ? I once weld my exhaust with brass rod and it finally got so hot on a long trip it melted and fell apart. what can I use ? thanks

Replacing with a new manifold will cost less money, take less time and will function better.

 

[Bob]

Unless it's a "rare" part, it's not worth messing with, replace it.

If you want to see what CAN be done by an expert to repair hard-to find castings, search for posts here by "george md", and check out photos of his work at the link below. LOTS of manifold repairs.



http://imageevent.com/gmachine

 

[Welding man]

I don't know if I am a pro or not but I have been in the welding business for over 40 years and have repaired my share of cast iron. My suggestion to you is to you if you're not a welder, leave it alone. You will fix it to the point nobody can fix it. A manifold is the hardest casting you can attempt to repair other than a stove or a furnace grate. They are already burnt up or hard as glass. The amount of time involved and the cost of materials to repair it will add up to the cost of a new one.

 

[MikeJM]

The cheapest, most cost and time effective way is to use your credit card and buy a new one for the Case 580, they are all over the place in the aftermarket world. Check it for flatness and put it on.

Like someone else said, unless it s a rare part and you can t find one, not worth the time to fix most times.

I would have paid good money for a good exhaust manifold for my bombardier J5 s Chrysler flathead if I could have found one instead of fixing it.

 

[Stephen Newell]

You would use a nickle rod however chances are the manifold would burn instead of weld. You might try it but if it doesn't go well quit soon and braze it. Like others have said, replace it if you can.

 

[560Dennis]

Aluminum bronze ,tig

 

[560Dennis]

Aluminum bronze ,tig
May be a alternate weld to consider

 

[george md]

what did you do to break,they rarely unless you hit a tree limb.
For repair of cast ,stay away from arc weld as it will give
you the most trouble with cracking because nickel and cast
do not expand at the same rate causing the repair to either
crack down the center of the weld or pull away from the base
material.Bronze has a similar problem as the rate of expansion
is different for each material.
acetylene and cast iron in stick form is a permanent repair
because the rod and the manifold are of very similar material.

Below here Bob posted a link to some repair of cast and other
things , take a tour.

george

 

[teddy52food]

When nickel didn't work, I used 7018 & had better results.

 

[fixerupper]

An old neighbor of mine claims the broken manifold on his dads 22-36 was welded successfully by working the tractor hard to get the manifold near red. While it was real hot it was welded while on the tractor, then the tractor was put back to work right away. I do not see how it could have been welded all the way around while it was bolted to the tractor and I doubt any prep work like grinding was done. This neighbor also was known to elaborate his stories so take it for what it is worth.

 

[MarkB_MI]

A while back I repaired a broken cast iron bench by brazing it. I was pretty happy with the results. If you think you'll scrap the manifold anyway, you might try brazing.

 

[teddy52food]

Problem is that the heat in the manifold changes the iron to where it is very hard to get brazing to stick. It needs extra flux to even try. Not enough on the coated rods.