cast iron welding.....HELP!

any one in socal...LA, IE are do cast metal welding. the intake many on my buick I8 is craked, like every other intake. i want to get a pc of shet metal welded over it to fix the prob...any one?

 

it could be..but not when there a chunck mising from the part..eather way it needs to get pluged with some thing and not jb weld.

 

ok.. so im going to post pics of the manifold and some one let me know if they can help...

 

so?

pics?

cast iron welding isnt alchemy... just like ANY welding, its science and practice

not all that hard to get a "donor" piece of cast iron from an old skillet or perhaps a cast off intake from another car and weld in a decent patch

 

i am a welder but i dont play with cast iron, i sent some stuff to a guy in maryland, he is an old school cast iron gas welder, there arent many around any more. im not talking brazing or nirod welding. he is also a machine shop. he did this heat riser deal for my es***, it had about 8 cracks, exhaust flowed through it to warm the intake air fuel mixture that went through the center. he did it cheap too. let me know if you want and ill see if i can get you his info.

 

Hi!

I do welding of cast iron in my shop!
Tell me how long the manifold is!! It needs to fit in my preheat oven!!
Not sure how much it would cost to ship it to the Denver area where I live!!
Sheet metal over it may not be the best approach.
I have a special rod for heli arcing cast.
But proper pre heating and post heating/cool down is very important!!

Let me know if you can not find someone in your area to do it properly!!

Monty
720-331-3104

 

I have a factory 41-42 compound carburetion setup for the 320 straight 8 if you are interested. Includes intake and exhaust manifolds, and both correct carburetors. No air cleaner or linkage.
Send me a PM.

Dan

 

I have done some cast iron welding with a tig and nickle rods with good results. I use a rosebud to preheat the clean base material and keep the entire piece hot while welding it. Once the weld is complete I put the piece in fine grain sand and make sure it is completely covered until it cools naturally.

Although in my opinion the best way to repair cast iron is with the spray welding process if you can find a local machine shop that does it.

 

IMO, you should try to at least get it tacked together while it is bolted to the block to prevent warp. The donor metal should be of nearly the same type of cast as the manifold ie., another old manifold. You can As mentioned before, it should be preheated, welded with nickel or stainless in short p***es with lots of peining, then post heated and cooled down slowly (packed in sand, wrapped in welding blankets, or some other form of insulation). Check with a straitedge when done---it may need planing.
Bob

 

I agree, bolt it to the head, have someone with a pre-heat set up and a cool down set up do it. Use a piece of cast from another manifold. Easy Peasy!

I'm doing a 348 block I have. The crack is about a foot long.

 

use a henrob torch, and a length of cast iron rod... not nickle or hardfacing ****... cast iron in the form of a rod.

i've done cast welding with a henrob. it CAN be done, at home by an amature, period. proper heat up and cool down is a must but if you've got the ambition to actually try and weld cast iron, you'll already know that much... rosebud tip to get it hot, and bury it in sand after to let it cool slow... common sense

 

I welded the T3 flange onto my exhaust manifold W/ steel rod & TIG. It's not pretty, but it's not coming off, either... I've welded a few CI things w/ success. It's kinda like welding fibergl***, but it works.

 

I own a specialized machine/shop and welding /fab business last 32 years. I do a lot of specialized welding repairs in all metals and have definite hands on background in cast iron repair.

That being said; here is the exact proceedure I would follow if you were a client bringing me in the manifold to repair:

My method is to use TIG and 99.9% pure nickel bare tig rod.

1) hot tank the manifold clean and rinse to rid all contaminants; or fuel and oil reside will bleed up from crack bottom and screw up the job.

2) at each end of the crack (termination point ) a 1/8" dia. thru hole must be drilled to terminate and forestall progression of the crack both during and after the welding process and once back in service.

3) using a die grinder with a small carbide burr (pointed) you gouge out the crack leaving a trough shaped groove around 3/16" to 1/4" wide and nearly the thickness of the casting , leaving around 3/32 to 1/8" of cast at the bottom (you can judge thickness by looking at sidewall of the drilled holes, that is your guide).

4) have a light duty air hammer at the ready with a chisel shaped narrow bit and adjust the air pressure for a mild impact.

5) take a propane torch (bernzomatic) and bring the weld zone to a mild preheat of around 400 to 500 degree F. Then start and work through methodically without pause.

6) lay in the root p*** w/TIG and nickel rod and the using the air hammer and lightly planish out and stretch the bead.

7) lay in the next p*** of nickel and planish again.

8) repeat the process and until fully filled and capped; then final planish with air hammer well to stretch out the fill.

9) allow to very slowly cool; I advise covering in insulating material such as vermiculite to slow the cooling rate. (kitty litter will work).

welding repairs in cast iron usually occur thru the welding process as the filler metal shrinks...that is why the planishing (peening) steps are so very important and keeping the heat in while welding followed by a very slow cooling.

If you follow these instructions the repair will be succesful.

I know it sounds like a lot of work but it really is not....I could do all this in around an hour with a cleaned manifold to begin with.

Best of luck....not required!

 

After reading other advices I want to add:

Do NOT use stainless rod.....it will not (fuse) bond with the cast iron , is too stiff to succesfully peen and shrinks too much....and the co-efficients af expansion between the two metals are too dissimilar...

Do not use cast iron rod or strips of cast iron as you cannot peen it and because it will be layed in molten will crack as it shrinks. To weld repair w/cast iron rod the entire manifold has to oven pre-heated to a very high temp and that will warp it out of shape. You are dealing with a pre-machined precision part with no allowance for remachining after to correct.

believe me....TIG and pure nickel will work...guaranteed!

And don't consider just overlaying w/a steel patch...the crack will still exist under the patch....and will only lengthen and get worse.

bye, bye....

 

another way to repair the crack WITHOUT using any form of WELDING and this can be done at home?:

drill and tap a hole beyond one end of crack and screw in a soft grade 2 bolt 1/4" dia tightly to the end of the thread on shank and then saw off the protruding shank and grind smooth. then take a sharp center punch, place in center of bolt shank and tap punch repeatedly w/a hammer to peen expand the steel...that will compression flare it outwards locking it up very solidly into the threads.

then dill/tap another similar hole overlapping the previous by 1/3 of the bolt shank diameter ; screw in another bolt to the shoulder of the threads ; saw off; grind off and center punch peen again.

work your way down the length of the crack this way until you are done the whole length....

this method of overlapping plugs works well.....if you like br*** bollts may be used.....and it does not hurt to use high strength, high temp. loc***e on each hole as well....

so there ya go....a simple home fix........

 

DUSTYRUSTEE

the real problem is, he's got an actual piece of the manifold MISSING. but the basic process will be the same

from your explanation, you do have a very firm grip on welding cast, and i'd love to stand behind you watching as you make repairs some time..

i for one have learned quite a bit from you post

 

If you weld on that without it bolted to a head it will warp, which makes it a bit difficult to preheat. I have brazed and Ni-rod, cast iron stick rod manifolds with an A/C stick welder with success. The consistence of cast really varies a lot so there is no carved in stone advice/absolute proceedure that works on every piece.
The last exhaust manifold I welded was on a roundy round car. It was a big points weekend and we couldn't find the needed truck manifold. The thing was **** and even the know-it-alls said I couldn't weld it. I did, with A/C cast iron rod from Harware Hank, and it was still together after 3 weekends of hard racing. I didn't preheat but welded about 1 inch and then peen the **** out of it, weld another inch and peen. Prep is pretty basic, bond is essential but the stress relieving is the real key to whether it will stay fixed or not.
Also for a slow cool down I have buried the part in the ashes inside my wood stove (no fire). That gave me about a 4 hour cool down.

 

If its just a crack grind it and weld with the ni-rod. If it is broken in two bolt it to a angle iron jig check it with a good strate edge and weld it like Willowbilly3 sayed

 

For those of you who have done this - How do you get the cast to melt cleanly? The only problem I have w/ welding cast is that 50% of it burns and farts away. I end up w/ a gouge where I run the torch. It feels like welding through paint or powerdercoat.

I always attributed this to a casting quality issue, any suggestions? I've tried pre-heating to no avail as well.

 

My pop used to weld cast iron stove grates and plow parts for the local farmers and the Amish folks.
He start a charcoal fire right on the garage floor, get it hot and lay the piece in it and let it get real hot.
He'd stick weld it (we had electricy) with a nickel rod and when finished he'd cover it with sand and leave it sit till cool enough to pick up with your hand.

He used to weld gas tanks too but that's another story

 

I have never had cast iron melt.

 

Well then apparantly you have never welded it.

 

I welded cast iron everyday for 25 years

 

Without melting it? Explain that one... It's not welding if you aren't melting the base material.

 

you cant cut cast iron with a torch.

 

Don't get me wrong, Im not trying to call you a ********ter.

I'm just saying that you can't weld a metal w/o melting it. That's just obvious. When I have welded CI in the past, it has been a ***** to get it to melt cleanly in the base material, It mostly just fizzles and pops.

I've never tried to cut it w/ a torch, but I don't see why you couldnt. It's ferrous metal - it melts.

 

Don't get me wrong but you can cut steel with a torch. You cant cut cast with a torch. So steel melts at a lower temp then cast Thats why I can say I have never had a problem with cast melting.

 

Sounds like we just aren't understanding each other.

My problem was getting it to melt, not having it melt out from under me when welding.

 

Tig is the best way to weld cast. arc is hard first preheat. Then jump around with the weld keeping the whole weld hot. You wont see melting like when welding steel. Look for a flat weld.If its a round weld its not hot enough.

 

I got the pexto stomp shear in my shop for free, cause someone dropped it trying to move and broke it in half. I TIG welded it back together with Nickel stick rod that I knocked the flux off of and cleaned with a scotch brite....also prep the cast iron really well, CLEAN and bevel it quite well, I have had alot of great success welding cast. Intakes and exhaust are a bit tougher, due to the contamination, but its possible, as we have done it alot. A bit of preheat doesnt hurt, 250 degrees (enough to sizzle spit).

There is also pics of a COLE flathead that we welded a cracked block, its possible, just takes a bit of leg work in prep.