Welding Tips for a lousy welder?

[Matt_in_Michigan]

My '61 Farmall 560 has a cracked exhaust manifold. It's cracked right where the exhaust pipe connects to the manifold. That whole area needs a good bead to seal it back up. I'm running a MAC Tools WS1300 MIG welder. I've ground around the whole crack, and welded it and ground it off 3 times. Am I missing something here? Or am I really that lousy a welder? Do I need a special wire for the manifold? Is it cast iron?

Any tips or help will be greatly appreciated.

Thanks,

Matt

 

[james rumph]

When you weld cast iron you weld it with "nickle rod" . You drill a small hole at the end of the crack to stop it from spreading ferther.

OR

You use a torch and braze it closed , which is a very good way of doing it .


A mig welder with standard wire won't penatrate like you need , plus the weld is so hard.

Nickle rod and brazing rod are soft and they will expand and contrat with the manifold as it heat cycles .

You could always find a local welding shop and have them do it .

 

[old]

Mig and cast don't mix unless you have an oven to heat it in. Plus manifolds are hard to weld no matter what because of all the carbon etc that gets into the cast. I would say buy a new one or take it to a michine shop
Hobby farm

 

[Dave Sherburne NY]

If you want to try again, sloooow down, weld a
short section let it cool completely then do it
I mean really take your time.

 

[moseed]

Grind and clean well. Using appropraite rod burn a bead no longer than 1/2 inch. Imediatley set down welder and grab small to medium head ball peen hammer, peening the weld (ball end) quickly and continuously as the bead looses color. Continue peening for 20-30 seconds after color loss. Repeat until finshed. The tapping actually helps the cooling molecules aline in a more organized array which helps reduce the risk of cracking as the piece cools. Proffessionals will stick the entire piece in a forge to reduce the temperature differential between the work and the weld so the cooling process happens to the entire piece rather than to a small portion of a cold piece, which is what causes the cracks.
Good luck!

 

[jose bagge]

I've always brazed cast manifolds...

 

[george md]

Matt,

When you get tired of having more failures
than successes with arc weld of any type , grab
your o/a torch , some cast iron in stick form ,
a can of flux ,and learn to properly weld cast.
Brazing is a reasonably good repair , but
works best on items that don't change temperature
much and manifolds don't fit that description
very well.
Your best repair is with o/a and cast rod .
Below are 2 pictures , before and after
repair with o/a . There is also a link to
many more pictures of that repair .

The third image is a 1929 waukesha manifold,
and yes it is repairable.

george

<p align="center">

Showing back of the broken heater box</p>

<p align="center">

assembled box , back side</p>

more cast repair

 

[Anonymous-0]

Prior comments are valid. No matter how you try you'll have to preheat the manifold. Hot. Hot. Hot.

 

[comtcwby]

If you are welding with a mig welder, switch to stainless steel wire. Preat the manifold or anything cast with either a torch or put it in the bottom of a 55 gal. drum with a light amount of gas to warm it up. A propane torch will work ok in small areas and for short welds. The reason that the area keeps cracking out is that the cast is cooling at a faster rate than your weld will. Stainless or nickle is the only rods that you should use to weld cast iron unless you are using a torch, then brazing will work. If you chose to use the mig welder, you will want a Argon based sheilding gas to eliminate and porosity in your welds. You dont need the cast to turn cherry red during preheat but all you need is to have it about 300 degrees. Maybe your wife will allow you to use her oven... I have done that before as well. Good luck.

 

[gitrib]

A mig welder will not work with any wire. Use a stick welder with small sized Ni-rod. groove the crack. Using a rose bud heating tip on your acytlene tanks, do not use welding tips, uniformly heat the entire manifold. Make sure and keep hot, may need a helper. Run a small short bead. Have a good sharp pointed peening hammer and peen. This removes the tension on the weld. May tack it to keep it aligned. KEEP IT HOT AND PEEN it after every run. it is slow work you cannot hurry. Make sure and KEEP IT HOT. have a pile of DRY sand when you are done bury it in the pile of DRY sand and forget till the next day. It is dificut but gives a lot of pride when you get done. GOOD LUCK