welded cast iron manifold with oxy/acetylene

This 292 Ford exhaust manifold has a deep groove resulting with a crack that goes three quarters around the manifold. I welded it with an oxygen acetylene torch and used old cast iron piston rings as filler.
One picture has a small light inserted into the manifold to illustrate the crack.

 

Cool. My Stude bellhousing has a broken 'ear'. I've thought of trying to fix it myself. Have a friend that could definantly repair it but I learn by doing

 

These pictures are after its welded, before and after I cleaned off the slag

 

Where is used to work we would weld exhaust manifolds . here is the tips to make it last . clamp to a bench. drill a circle in the end of the crack to stop it from running at both ends. warm it with a torch or cold we have done both some guys like to warm them . Use a high nickel rod and stick welder . works great

 

Could you be a little more informative. What piston ring? What gas settings? What tip? Did you preheat the manifold?

 

top of manifold

 

It could be considered Finished but you know, more is better and too much is just right. I used the grinder to smooth up and sprayed a little flat black so it will photograph well

 

The oxygen acetylene welder I used is a Henrob and cast iron is used for filler. I have done this before on a manifold that had an ear broken off. I built up with weld, then dressed it to shape and drilled and tapped the hole. It is still good 21 years later.

 

Any cast iron ring. The Henrob uses 4 pounds of pressure for both gases. Number 2 tip. A light preheat is a good idea.

 

very nice job

 

I had a welder at work weld up the tab for the thermostat housing on my flathead. He used an stick welder and some special rod. I will post the rod # when I get in my shed next. It worked out real good, been holding on for a couple thousand miles now without any problems

 

Man what a deal this is - Use what you have - No special Rod to buy or stock

Gee Wiz - Bet they done stuff like this before stick & wire -

 

Well done.

 

thanks. speaking of using what you have.. nice save,
drilling the hole at each end of a crack seems logical will remember this tip.
chris.

 

Looks great!

I'm going to have to learn to do that at some point. I have a MIG but I'd still like to try my hand at welding with a torch some time.

 

I have welded up many cast iron manifolds using oxy/acetylene, br*** rod and brazing flux. It is a good idea to drill a hole at the end of the cracks and to clamp the manifold down before heating it..
In the late '40's, early '50's the majority of split manifolds were made by brazing with oxy/acet.. As time progressed and we got smarter, we starting using a stick welder and nickel rod

 

Exhaust manifolds are tricky to weld because they usually aren't made of a good grade of cast and the exhaust leaves carbon in the crack. Another problem is that many cracks are caused by bad design of the manifold so too much heat is concentrated at one point or too much stress is transferred to an area.

With a torch, you can use the gas mixture to control the carbon content. Specialty electrodes do the same when arc welding. There are likely specialized flux core wires to do the same with mig. I like to bolt the manifold to a head if possible.

 

*we got smarter, we started using a stick welder and nickel rod* ?

Take your foot off the gas - Read the Sheaving Cream Sign's - The Art of Doing <!-- / message --><!-- sig -->

 

Great job there. I have welded many cast iron exhaust manifolds in my life time. Some just can't be fixed, burnt to the point of no iron left to weld. What flux did you use with the filler material? One thing I've noticed over the years is that ford iron has more nickle in it that gm or chrysler products do which make them easier to weld. Well in any case you did a great job of turning that manifold into a silk purse....

 

I'm older than dirt!!---The "old way" was to bevel both pcs. about 45 degrees, set oxy at 30, acet. at 7, using gasket for alignment holes clamp down both pcs., preheat with large tip, all around LARGE area to dull red.
Open can of flux for cast iron, heat up cast iron rod, dip in flux, & begin to apply with feather on tip of torch, "Tack" opposite sides, then start your welding out process.
When finished, reheat large area again to dull red to relieve stress, let cool naturally to touch & recheck alignment to head.-----Don (welding since 1951).

 

Hell, I have only been welding since 1963, bet you could teach me a thing or two.

 

Don, Is cast iron flux avaialble from most welding supply places or is it a special "home brew?"

 

Thanks for the comments guys. I used Petersens No. 2 High Heat Flux.

I often like to repair rather than replace and prefer to weld using similar base metals. It seems wrong to Braze cast iron together.

 

The "old" can used to be called "Brazo" flux.

 

About 10 years ago I stopped at a local welding supply to pick up some flux for cast iron and they told me there's no such thing. They said you only use flux for brazing. I had to get them to look in a catalog. There are quite a few flux formulas for welding and brazing various metals. See the link below.

http://www.brazing.com/products/fluxes/index_weldingflux.asp

 

We used a cast rod that was about 3/16" square in cross section and about 18" in length , can't for the life of me , remember the brand of flux . I do know Boraxo powdered hand soap would do in a pinch. I worked in a pump repair shop back in the mid fifties and later in several muffler shops here in Vegas. After a good preheat one would dip the rod in flux and add the filler, kinda reminded me of daubing mud and it wasn't real pretty either but it held fine.

 

How large of an area around the crack did you pre-heat? I have a fully ported 235 Chevy head I'd sure like to save - cracked across the top, above a water jacket. I would bolt it down to a old block if I tried it. Think it would work? Got any more cast rings?

Thanks, Tim

 

'Preheat' is such a harsh word. It is more like 'lightly warmup'.
I think of 'preheat' as setting the piece on a gas burner (think fish fry)
but welding a smallish piece like the exhaust manifold with a Henrob only involves waving the torch over the piece to warm it up some.
For welding a large item like a head, the fish fry gas burner would probably be a good idea but bolting it to a giant heat sink like a block might prevent the head from getting hot enough to weld

 

The filler rod can be seen at the top in this picture
Good luck finding it at a welder supply. They look at you like you're from Mars

 

We just stick welded cast iron with NyeRod, not sure of the spelling. Heated it a little with a torch and went at it with the stick...