Welding Cast Iron

I am restoring a 1950 Buick and have a severly cracked center manifold. In researching CAST IRON WELDING I came across your web site and read the thread on cast welding.. I have also reviewed information from http://www.muggyweld.com They have 2 rods (72 & 77) that they advertise as the fix all of cast iron. The question I have is... Has anyone used these and do you have any comments. thanks and keep steaming...




Cast Iron Welding

I have never bought anything ( of THIS nature anyway) that cost $105 a pound! If I had to charge a customer for such a rod as this, well........All you need is a stick of 1/4" plain gray iron rod, some borax flux and a torch. I don't care if you drill 10 holes, if it's gonna crack it's gonna crack. A slow cooling down period might help prevent cracking. I'm sure you're dealing with burned out cast but this is the way to get it done. Even if the cast is burned out you can still weld a steel sheet over any holes or the joint using the cast rod. Craig

I've looked at Muggyweld before, and I think that guy left a failing carear selling Aluminum "welding" kits at county fairs when he found the internet. Welding cast is rarely simple, and manifolds vie with the Mexican cast iron lawn furniture for the worst castings to weld. For a new weldor to be told he can weld cast if he buys a product is stealing money from a sucker. Depending on the actual condition of the manifold, you might elect anything from welding to everdure to brazing.

I haven't welded exhaust manifolds because I've always heard that it's almost impossible to weld them. An acquaintance took a rare one-of-a-kind manifold to an antique engine rebuild shop in order to have a short 1-inch crack repaired.

The shop gave up after chasing the crack three inches and the crack was still there. Worst of all was three inches of the worst "chicken droppings" bead I've ever seen.

My advice? Don't try it yourself. Keep looking until you find the most experienced welder you can find, one who has been there and done that.

My 2¢

Orrin

After preheating and welding, immediately put the part in a container full of Vermiculite insulation. Buy yourself a metal garbage can with a lid at a home improvement store, and fill it with Vermiculite insulation that you can buy at the same home improvement store. As soon as you are done welding your part, bury the part in the insulation. Make sure it is surrounded very well by the insulation, and be sure it is completely covered up. Leave it covered for about three days. Even after you take the part out of the garbage can three days later it will still be very warm, so be careful. This is an excellent way to let the part cool slowly to help prevent cracking.

Agree with the others, don't try welding cast iron manifolds. Ask around for the best welder. Try the local community college instructor, ask at an aircraft repair place.

Personally, I think brazing with flux coated rod and oxy/acetyl heat is the way to go, much more control.

[Eddie Cannon]

I have been in the welding business for 15 years and have experience dealing with cast iron repairs. The most effective way I have used is to spray weld the part with a Stoody powder spray torch using TG63 powder. This process has been around a long time but few people know much about it. The advantage is the part remains heated during the process and you can control the thermal shock to the part by preheating it. As with all repairs each one is unique and there is no one fits all approach. Some parts should not be fixed and others due to thermal stress will crack during controlled cooling. As with all cast material cooling rate is critical.

[11echo]

I've had some success welding cracked cast iron. BUT I do not put myself up as an expert! ...Just lucky maybe *G* ...I'm the typical shade tree mechanic type, like to re-build big block chevy engines. Anyway I had an engine with a cracked exhuast manifold. I didn't like what the dealer or the local junk yards wanted for a replacement, so after talking with a welder friend and the welding supply shop, I picked up some "NICAD" rod for my "buzz box". I pre-heated the manifold in the BBQ and quickly welded it up (note: you don't have to do much beveling, this stuff is deep penetrating!). Then quickly put it back into the BBQ and let the coals burn out ...weld was solid the next day. Now maybe I was lucky or I found a way that "normally" works ...not sure, but if your like me it's worth a shot! Good Luck with your project!!! ...Mark

[paul t]

Here's what I did for a gear case.

Got a barbacue
Loaded it up with charcol.
Nested the part in the mound of charcol.
Shrouded the part with some woven asbestos cloth.
Got some Tempil sticks...600 and 900 degrees.
Hoped to get 1100 degrees but went for it at about 900.
Brazed it with oxyacetylene.
Had to make a heat shield for the torch with an aluminum plate and some asbestos cloth clamped to the torch with hose clamps.
Covered the whole thing up with some more asbestos cloth when I was finished.
Came back the next day.
Worked good. No distortion.

[Andy Romness]

My Dead uncle Pete could weld anything! had him do several cast iron welds for me over the years and here is what he would do. Build box around part with fire brick and place tulip head torch into box heat part to red hot all over pull brick back enough to weld with old DC stick welder, cool part over DAYS............ Good as new maybre even better!

[arkot]

Engine manifold is a tricky part to weld repair.Welding with sprayweld Nickel powder is possible if the thickness of weld is less than 1/16"( 1.5mm).

Gas welding cast iron is a elaborate process of preheating to red hot temperature, maintaining the heat by keeping the part covered so that the ed hot temperature is maintained while gas welding with suitable gas welding rod.Also slow cooling to room temperature is required after the welding is completed by covering with proper insulating material.

The weldor should have high degree of skill and experience in gas welding.

The arc welding with suitable NiFe electrode and the process of cold welding will be easier and more reliably successful,without necessarily having a highly skilled weldor.

[Skip Landis]

here's my story, had a 4 horse new holland with a cracked flywheel hub. tried nirod several times, looked ok, but you could chip it right back out. rotton cast, similar to burned out cast. my brother who had a weld shop gave me a cast rod as Craig said, told me to strip a oiece of ordinary house wire & wrap it around the cast stick at about 1/4" lead. i put the flywheel on top of my shop stove, let it get good & hot then torch welded the crack. left it cool down with the stove. worked great!!! he discovered this by trial & error trying to weld furnace grates which are much like a burned out manifold. skip

[arkot]

Most of the engine parts are made of grey cast iron. Static parts like engine blocks, gear boxes, crank cases are mostly grey cast iron. Dynamic parts like rocker arms, flywheels etc. are made of malleable cast iron or cast steel.

There are many grades of cast iron. It is very essential while arc welding cast iron to select a good electrode which shows a good weldability on the particular cast iron.

Most of the 55% to 60% Ni rods give good bonding on most of the cast irons.

However when we encounter a 'dirty' cast iron ( having more Silica, or Sulphur
etc.),the weldability is not good.
The trick to get good weldability is 1. to make the part oil free, by soaking in Caustic soda solution for 24 hours and then rinsing it in water.

2. Cover the repair portion with one run of available Nickel electrode. Grind the deposit leaving a thin layer on cast iron. This is called 'Buttering' technik. Then complete the repair

I have repaired 100's of cast iron parts successfully using the technique of cold arc welding.
:

[Paul Schultz]

I'm guessing that you're doing a complete restoration and would like the part to have as close to original appearance as possible. Ordinarily I'd suggest brazing but then it wouldn't look original so instead get some cast iron rod http://valley-forge-welding.amazonwe...source=froogle and go ahead with oxy-acetylene fusion welding.

One suggestion I would make would be to either bolt or clamp the manifold to a chunk of steel to keep the surface straight. Preheat both the manifold and whatever it's clamped to as a unit, drill both ends of the crack to keep it from spreading, then grind the crack out a bit and weld. As soon as welding is finished, bury it in ashes and let it cool for a day or so. After it's cooled, gently grind the weld to contour and use a needle scaler to match the rest of the surface. After sandblasting you're going to have to look close to see the repair.

[Robert and Jason Lange]

Our shop has been in business for 60 years! The only way to weld a manafold and get it to hold is with cast iron rod and a torch. People will tell you nickle will work it might for awhile but will cack and looks like crap. Some say weld it with bronze THIS WILL NOT WORK!!!!!! The exhuast will eat up the bronze and the heat will work hardin it. We have rebuilt intake and exhaust manafolds for 60 and 65 Cats and have had very good luck and they are done so they don't even look like they have been welded. I am the third generation in this shop and we have ground out and fix alot of the other so called experts crap and done it right. I hope this will help you. Jason

[Roger S]

Hi just my 2 cents worth
Had an old engine with a cracked manifold and wanted to shut it up so I V ed out the crack and welded welded while it was still bolted to the head with a 110v meg welder with odrinary 024 wire on the outside then pulled it and did the same on the in side (head side) no heating to my surprise this manifold lasted the rest of that engines life another 2 years.
I don't recomend this but it worked

[WyoBoilerMaker]

good preheat is a must an must be as clean as posible , cast is nothing to make promises on but some times you get lucky.

[OTTO-Sawyer]

I'll have to check in with my Dad and see what rod he used to use. He's welded damn near anything that can be welded and a lot of things that people said couldn't be welded. He's been fixing broken manifolds, splitting and welding manifolds for making dual exhausts on straight sixes, dual quad intakes for cars that the aftermarket didn't cater to , welding steel and iron together, etc., etc. and very rarely has ever had to re-weld anything. Broken pistons I think he just brazed back together instead of wleding, but that's a whole 'nother story.

I'm sure Joe Maurer and at least a hundred other people could testify to his welding abilities. Of course he's been doing it since the early - mid 50's too though, so he's had some practice at it. Other than preheating around the weld area with a torch, I don't know that he ever did anything special when welding any of it, and a lot of stuff he welded was still in place on some of the larger equipment, so there was never any insulation or other crap wrapped around it to give it three days to cool down. One of the Steam Engines being hauled in to our show once back in the 1970's failed to clear an overpass and got the smokestack busted off of it , and Dad welded that back together with it still up on the engine at the fairgrounds with whatever breeze there was that day blowing around it which I'm sure affected how fast it cooled down, and that worked out just fine as well.

New iron or old dirty brittle stuff, it didn't seem to matter with him... if it was broke, he fixed it. He's retired in Texas now and doesn't have a welder anymore, but once in a while would take something to a shop and use their equipment to show them how to weld.

I haven't tried it myself yet as my wirefeed welder is set up for flux core instead of the gas bottle, but I've heard that stainless steel wire is supposed to work pretty good for welding old iron with a mig welder. I'd practice on some old ford or chevy manifolds from the junk yard to build up a little skill before jumping in on something you plan on using though. You don't want to pactice on something you need done right.

[Harold Price]

I have a valve box from a 25hp superior that had a ¼ inch by 3 inch piece burnt out right along side of the valve seat. When I got the engine it had been brazed shut. When I put water in it leaked into the valve and into the head and out the cylinder. When I taped on the braze it all fell out. I sand blasted the spot real clean and it is in a very hard spot to get at and right along side the valve seat. This is one more reason I am not a big believer in brazing. You get it red hot and it takes days to cool it down and then you hope it does not crack again. I saw this Muggy weld on the internet at about $100 for 14 rods 7-#72 and 7-#77. I have welded a lot of cast with nickel rod and it is hard to work with and hard to find one that will work on the cast you are welding. I thought this is a lot of money to try something new but there are new things out there that do work and I hoped this would work like the screw top on a beer bottle did. I welded a small spot on the worst dirtiest place I could find and it went real good. I took a hammer and chisel and beat on it and it was just like it was part of the casting. I made a pass down each side of the gap with the #72 rod and cleaned the slag out real good. Then I weaved the gap shut with #72 and went over it with #77. Then I went inside and run a pass around by the valve seat with #77. I started by heating the casting with a torch just to take the chill out and you could still pick it up with your hands. The whole thing about one hour and a half. I die tested it and put it back on the engine and filled it with water and it is fine. It worked for me and was worth the $107 I paid for it.

[capt will]

About welding your cast iron manifold, I've had great success using a castolin/eutectic stick rod #2240. It is a very forgiving rod and can be used ac/dc. It doesn't require preheating and runs a nice bead. If you still need to do this job, get those rods if you can. Good luck, Capt. Will