I am wanting to fabricate some dual exhaust manifolds for the slants in my brother's van and his Duster. My question is what is the best method of welding the manifolds?

I have access to a stick welder and a wire feed welder (no shielding gas though). I was researching and saw a welding stick called "Certanium" recommended. Here is the website: http://www.certaniumgroup.com/cert%20ing%20h%20777.html

The 777 stick sounds pretty good for welding an exhaust manifold. Anybody have any experience with it? How about the 790?

What about other sticks for welding cast iron manifolds?

Thanks.

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Casually looking for a Clifford hyperpak intake for cheap.

Reading the tech specs for the Certanium, you will have to heat your manifold and metal to weld up to 400 degrees before you can begin welding, you'll also need a thermal blanket/rock wool insulation to let it slowly cool down so it doesn't crack the welds.

Better find out what they are charging for that stuff, I'm curious how much a box of rods are going to cost you.

-D.Idiot

Hmmm. The web page says preheating is not required. Liars. I have an oven and some old ove-gloves. That could get the manifolds up to 400 degrees.

I still need to track down a supplier for this stuff. Any other brands/sticks I should be considering? There are several welding shops around where I live, and i also have a Lowe's and Home Depot close by that carry a limited stock of welding rods.

Any thoughts on Muggyweld? http://muggyweld.com/castiron.html

How about Softweld® 99Ni and Softweld® 55Ni, the Lincoln Electric® electrodes designed for welding cast iron?

Thanks Rob!

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Casually looking for a Clifford hyperpak intake for cheap.

Lowes may be able to special order what you need if it's from one of their normal suppliers..........

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

.........so why doesn t everybody do this?

Once an exhaust manifold has been used it is almost impossible to weld. If you have a fresh manifold it might be possible.

I worked in a machine shop in the late 70s and saw many a cracked slant manifold come through the door. The pros with all the equipment and expertise could not weld them to last.

The real market in this shop was log truck stuff. A truck manifold was almost always successful but the time it took was enormous. Yer pizza oven wont do this Guido......

The rod and its cost is the least part of this game.

If you must do this..... Get all the pieces ready to weld and take it some where. Ready to weld means each piece fits exactly together and all mating edges are ground ready for the root weld.

If you do it yourself you will still need to do the same prep.

Magically Old Dude at the right machine shop is going to charge you 1 hour and the cost of the rod. Engage him in conversation.......

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Yeah....Im the one who destroyed this rare, vintage automobile.....

This page is from a supplier of the dch2000(henrob) torch. Includes an instructional video and tips that could be helpful no matter your brand of torch.

Have heard from various sources that it's possible with a mig, even welded some pieces of black iron pipe to a flange for a turbo downpipe by torching them to preheat then miggging (?). Don't know if that's the same animal as a manifold though.

Given sandy's comment about new vs. used I suppose not.

Are you trying to fab some log style manifolds from new pipe stock or modify a used factory manifold?

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72 dart acquired 12/08 /6,holley2b, mopar perf intake, mopar perf header, cam, built motor,904 finally re-installed, 8.75....still needs sorting out.
99 dakota 318 5 speed reg cab picked up 9/09; Trans finally fixed! woohoo!

I am trying to modify stock manifolds into dual exhaust manifolds through cutting and welding. This sounds difficult. Has anyone had luck following Doc's instructions re: fabricating a rear manifold for Dutra Duals? That is what I am going off of.

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Casually looking for a Clifford hyperpak intake for cheap.

Dougs instructions are excellent.

You should try a rear version first following his plan. One version has you bolting the pieces together. Thats how tight the fitting needs to be.
If I were doing a rear I would make a lapped joint and bolt it together.

A lapped joint is where two pieces are fitted together by using grinding compound between them . Apply compound ....rub pieces together till perfect fit is achieved. You start with a flat file.

You cannot fill holes with weld....yo can only stitch tight fitting pieces together. The teeniest hole will just get bigger.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Hmmmm. Thanks Sandy. Maybe I will take some manifolds out to a machine shop and see what they would charge to make up some rear pieces.

I do have a homemade front manifold that someone else made up. It looks like it has been run before and looks leak free (no obvious signs of blacking around any seam or holes from exhaust leaks).

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Casually looking for a Clifford hyperpak intake for cheap.

I don't really have any helpful advice for you on this subject, I've always taken exhaust manifolds to a welder to get 'em done right. I subscribe to the DIY philosophy, but there is an experienced welder in my neighborhood, so I pay him a few bucks to do the job.
I also don't have ANY welding equipment, and our garage is packed full of stuff that we plan to put in our garage sale, someday...
Kudos to ya Reed!

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"Ja, Ich fahre ein altes auto."
'78 Volare 225
'67 Charger 318

if you decide to weld it yourself you might try Mc master carr they have a welding wire,NI 55 Cast Iron, that is suppose to weld cast iron its flux core so a shield gas isn't needed. Sandy in BC is right when cast is heated it can be hard to weld ,it gets hard spots. It might be possible, i have heard of welding engine blocks on rare tractors. Your best bet to weld it would probably be to heat it up HOT 900-1,000 f and EVENLY to avoid cracking and weld it with a nickle baring rod or wire wile its hot and tap it with a slag hammer til its cooled some after your done , that is supposed to re leave stresses in the metal. Personally i would prepare the joints as if to do a butt weld and braze it with brass rod. good luck with it

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85 d-100 HEI 2BBl
06 Toyota Corrola

Thanks! I will ask around at machine and welding shops and see if anyone knows someone who can do this on the cheap. I just don't know enough about welding to do this job right.

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Casually looking for a Clifford hyperpak intake for cheap.

If you don't mine me asking what are the benifits to dualing up ur exhaust on a slant 6.

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68 225 Dart "life under the hood, is the life for me" -By Me

Increased flow, smoother flow pattern, elimination of the potential cracked exhaust manifold syndrome.

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Casually looking for a Clifford hyperpak intake for cheap.

Wish mean hp increase?
And if yes do you know by how much?

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68 225 Dart "life under the hood, is the life for me" -By Me