Cast Iron Repair and Needle Scaler

[killdozerd11]

Brazeing it should not be a problem...it's thin cast

Don't forget to drill a hole at the end of that crack

 

[irishwoodsman]

the needle scaler works great for pinging castiron welding with a arc welder, but this should be done in inch sections so that the castiron does not cool to quick before the pinging is done, what your doing is expanding the molocules of the metal so it does not shrink and crack your castiron, i have used this method for many yrs on fresh water pumps used in shallow wells, brazing is more forgiving if you preheat your castiron in a barbque grill before brazing.

 

[Junkmaster]

Here are the results of my brazing. It isn't great, but its functional. For some reason I thought I had to rush, which never delivers a good result.

First I took a Sharpe marker and traced out the crack. You'll see the 4 holes I drilled in the images below. Two holes were for short the branch cracks off to the side of the big one. One was where I thought the cracked ended. One was for the actual end of the crack.




Next I took a die grinder and carbide bit and gouged out a trench about 3/8 to 1/2 inch wide. I left about 1/8 to 3/16 of an inch of material at the bottom.


I did not take pictures of the clamping. I clamped a 1/2 x 4 x 24 piece of cold rolled steel across the open face. I started with two clamps. About 1/3 of the way through I looked at the remainder of the crack and it had openned considerably. So I added a third clamp. This is when I started getting nervous and rushed.

I brazed following a similar procedure as Keith in the Machine Wright video: warmed the whole thing by running the torch over it for 2-3 minutes; warmed the general area around the crack for 1-2 minutes; starting at the root of the crack turned the metal cherry red and dabbed the brazing rod and flux into the flame. When I wasn't rushing the brazing looks almost like a good arc weld (slight ripples). When I got nervous and started rushing it looks like someone sneezed brass all over the crack. I might just be related to a dyslexic monkey:rofl:

I also watch Welding Tips and Tricks on You-Tube. That guy can really weld, and he can take good videos of him welding. He doesn't even think about it but he dips the rod into the puddle and backs out. That really does work.


I wrapped the piece (with clamps and 1/2 Cold rolled) in a welding blanket and let it sit for about 3 hours. I was surprised that it was still warm to the touch.

I plan to grind the braze down smooth then fill in the valleys with bond-o then prime.

Thanks to all of you for the tips, pointers and links.

Evan R.

 

[Rbeckett]

Thats a fact, Jody at Welding Tips does a great job photographing the welds and explaining what he is doing. Brazing can be approached the same as soldering, apply enough heat to the item being welded, then dab the rod into the crack under the flame from the torch and if the temp is right it will suck the filler rod into the crack very nicely. Patience and prep are key to CI, as well as allowing it to cool slowly after a repair. I actually prefer to braze CI unless it is a highly stressed part, then there is no other choice but to stick weld with a nickek iron rod and cool over a day. When I stick weld CI I heat the casting tocherry red before I strike up the arc and weld in 1 inch interupted patterns to avoid crack propagation. I also drill a small hole in each end to prevent the crack from spreading. Looks good for a beginner, next time you'll know and do a much better job too.
Bob, "another dyslexic monkey at heart"

 

[7HC]

You got it done, good job! The next time will be even better because you'll have the confidence not to rush. :thumbzup:


M

 

[irishwoodsman]

you can hold your tip pointing forward a tad as you aply your rod and your bead will follow your rod, this takes practice. for your first time doing not bad. i remember my first test i had to take brazing, they gave you two 3x4x3/8 pieices of castiron, you had to braze the 2 pieces together then they put it on a press and crushed down untill it broke the castiron had to break but not in the weld area.

 

[killdozerd11]

Good Job