welding Super M exhaust manifold

Also, be carefull on cast that is supposed to get hot. Welding with a similar metal (gas cast iron welding rod) will expand nearly the same when the manifold gets hot again. Not sure about the nickel rods though.

Good luck..... ....

I recently welded a steering bracket on an M and a another small front end piece on an A. Those were my first attempts at cast stick welding (I spend most of my welding time using a pulsed MIG machine), but they seem to have worked just dandy.

I know there are a couple of schools of thought on how to weld cast, i.e. preheat or not, but I elected not to preheat. There wasn't a good theoretical reason behind this...it was mostly because I don't have a oxyaxl setup and I couldn't get away with baking the part in the kitchen oven ;-). In any case, I took it nice and slow...laid down about 3/4" of bead, then I went off and did something else for 5 or 10 minutes. Came back, laid another 3/4" of bead as far away from the previous one as possible, and so on. Just tried to keep the part as cool as possible.

Also, when I bought my cast rod, the welding shop guys suggested a more spendy rod...it's UTP Econocast 99. I'm using 1/8" rod, and I got 1 lb. (about 20 sticks) for something like $30. Since it's the only one I've used, I can't compare it, but it seems to have worked well.

Finally, here's a link to an article by Lincoln Electric I've found useful.

Have fun, and feel free to ping me for pics or anything else that might be helpful.

- David

• Cast Iron Welding Article

george

• manifold repair

Unfortunately we amateurs don't have that kind of equipment.

Why do you prefer gas over stick welding? I have gas and am better at it than the stick but thought gas would require too much heat and warp everything.

I welded short lengths at a time with the stick like another poster did, but with gas it would seem that you wouldn't want to do that because it takes so much gas and time to reheat.

Oxy/acet cast iron is the best repair for cast
followed by brazing and the absolute worst choice
is arc welding. Any arc rod that will weld cast iron will have a hi- nickle content , nickle is
about twice the tensil strength of cast and most
important it has a much greater rate of expansion
and contraction than cast . Cast is not ductile
and can not give a little as the weld cools and
that when the cracks start.It doesn't matter how
many chipping hammers you wear out peening the
arc weld bead , when you start the engine the
manifold and weld change size again and do it
every time you start and stop.Eventually the weld pulls away from the base material. For
manifolds heat a large section or all to a dull
red before welding , use reasonable amount of flux with the cast iron rod and maintain heat
for a while after welding.

Below is a link to how to weld cast , there are several pages , read all of them.

george

• cast iron welding

I guess I thought the hardness of studs made them break but now that I give it more thought it is probably the combination of heating and cooling and the rusted-on nuts that are the real problem.

I quit using hardened extractors years ago, I found out the hard way!

How do you heat manifolds? Is it ok to heat them with an electric arc torch?

I have read somewhere that one should never attempt to weld a British car exh manifold. Have you heard of this?

I haven't read the link article but will soon.

Thanks again,

Gus

I heat large areas or castings with a large
propane torch (looks like a weed burner-probably
is ). Build a fire brick oven around what you are
heating with a hole in it to put to propane torch
thru. Partially cover the top with brick leaving
enough room to access the area to weld , When done
post heat and I use an asbestos blanket to cover
the brick while cooling. Takes about 10 to 12 hrs to cool to touch.

I had an alfa-rameo (spelling) manifold to weld about a month ago, seemed like it was ceramic
coated , had to grind off the coating then weld.
The cast was miserable to weld ,but it does weld. Email is in the web site .

george

I had never tried to weld cast iron before and it worked so well I was really surprised. It probably has more steel in it than exhaust manifolds but I don't know for sure.

The bracket isn't very big so heating was not the problem it would be with a manifold.

Let us know how it turns out.

Just my 2 cents…