Cast iron welding clip. Anyone ever tried it?

[sportbike]

Sometimes the part can be placed in vermiculite after welding to make it cool very slowly.

Silicon Bronze filler is a good choice for some items, including hardened tool steel that may otherwise crack. I have seen it used on tooling adn machine compontnes (tailstocks for lathes for example) that are hardened. Not going to get the same strength as original, but it helps to prevent cracking.

[jakeru]

I tried some cast iron welding on a gray cast iron automotive intake manifold, without much regard for pre or post heating. I just cut some slices partway through the manifold, and tried welding them back up closed using a variety of methods. Let them air cool, waited for it to be cool enough to touch in between weld attempts.

I had a very nice result TIG weld/braizing in AC mode using aluminum bronze filler rod. The bronze seemed to be quite crack resistant, even without any serious pre or post heating. The AC mode seems to help keep the puddle a lot cleaner, and may prep the base metals for welding better than DCEN as well.

TIG welding with DCEN and 309L stainless filler rod resulted in a crack forming while part was cooling, right where the base metal joined to the weld deposit. Apparently there was poor fusion between the two.

Stick welding with 6013 electrode showed some promise, although I need stick welding more practice to really determine how it works when done properly. I think I was running it way too hot and just blowing through. Although I noted there was some cracking tendencies, the cracks didn't form along the edge of the deposit, I only noticed them in the middle of the deposited material. Which tells me the weld metal to parent metal interface was sound.

I picked a small quantity of nickel rods, which I'd like to try next. They are supposed to work well for cast iron welding, but boy are they pricey. I paid $3 per stick.

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Edit: here are some pics of my cast iron experiments.

I hacked up a 1960's era, gray cast iron automotive intake manifold with the cutoff wheel as shown, for cast welding experiments as described above.
Attachment 1650

This joint, which I didn't prepare very well at all, (also didn't bevel at all) worked pretty well with TIG aluminum bronze. There is one small discontinuity in the weld if you look close it will be obvious, but considering the "quick and dirty first attempt", I'd say it did pretty well overall. This is shown after flap-wheel grinding the weld bead down to see what's underneath the surface. It's kind of interesting how "TIG weld-braizing" melts some of the parent metals, yet if you look closely, you can see "islands" of parent metal (silvery color) that have not mixed with the bronze braze material (yellowish color.) I could probably use some more practice/development of my TIG weld-braizing on cast technique, but I'd say that is a pretty promising result for a first, very "quick and dirty" attempt.
Attachment 1651Attachment 1652

I tried using 309L stainless on a pretty well prepared area with a fairly large "Vee". It was dirty (oily) on the back side of the joint, which I'm sure did not help. (Possible hydrogen embrittlement.) I was doing a multi-pass weld. The initial tack welds and first "root pass" were holding up, but on the final pass, I got a crack right along the fusion zone of the earlier weld, a little way into it, and stopped to check it out. You can see the crack, along the bottom edge of the fusion zone, as shown in the pic. (Disregard the "spatter BB's" from subsequently attempted nearby stick weld.)
Attachment 1653

I'm not going to post my stick weld attempts because I need way more practice stick welding before being able to know what its capable of. I am really more of a two handed process (TIG/oxy-fuel) welding guy. I did just pick up 5 lbs of Lincoln 6013 3/32", I might do some practicing with. Those would be much better to learn the process with than using the $3/stick Ni-rod, I was thinking.