Cast Iron Block Welding

[RajinCajunBronco]

Ok, this looked like the best place to start this.

I have an 83 F-250 with the 6.9 Diesel and Banks Turbo...it has a crack in the block from the rear freeze plug where the block heater was(long story, this is the 2nd block to crack in this truck in the same place...will never use a freeze plug heater again)
I talked to my welding instructor (I am 33 so don't think I am a whipper snapper just learning..LOL! Been welding steady with my MIG for about 8+ years, just wanted to get some formal training and the Military is paying for it )

Ok, back to the question, my instructor said he felt confident he could weld it, and if I bought the rods he would give it a shot..so I went and spent $20 on 11 Ni-Rods. Well I had a little time so I started searching on the net and a local company Brecko Corp that sells Magna rods popped up, and they are in Abilene.. I though awesome, I can talk to them face to face. I read A LOT of info on their site and others about the new rods. Check their site www.breckocorp.com for info.
I went by and talked to the guys, and got a few rods...now I won't lie, the price is high for the Magna 770's, to the tune of about $105 a pound, but they will sell less than a pound. They gave me a great deal on some 3/32 Magna 770 rods and gave me a few extra to pass around.
We welded it up last night and it looks great and very promising, I was just wondering if anyone here has had any experience with them or something similiar? One word of caution, if you are not comfortable with ARC welding I would suggest getting someone else to do it...the cast block was very brittle and he had to show his experience...whic he did beautifully..LOL! He is a certified welder/instructor/inspector and been welding for 30+ years.
I will be machining the freeze plug hole a little since we welded into the hole a little where it was cracked. Oh, I beveled it the length of the crack and put a small stop drill hole just past the end of the crack to prep it. I will get some pics tonight and post results and long term testing... Keep your fingers crossed.
I just wanted to try something and the Ni-Rods didn't have good results from what I read...it was really hit or miss with them.

[wheelin66bronco]

Not sure about Ni-Rods but I Braized a 8" crack in my diesel tractor block. It has lasted a hundred hours or so now.

[RajinCajunBronco]

Well, I am sad to say I have about 90% success with the welding. Where we welded did great and looks great(pic link below)..BUT I now have another small crack across the end of where we stopped the weld... It is about 2" long.. Now in the defense of the new rods, we did not do exactly like the instructions. It said to drill a hole just past the end of the crack, tap it and screw a bolt in, then cut the head off flush with the block..this will allow it to expand etc during the welding and cooling process. I was already set to weld it when I got the instructions, so I was not going to delay it another day.. I had beveled the crack with a grinder and drilled a small hole at the end of the crack about 1/8" deep. I think the main thing that contributed to the new crack is the rear of the block where it gets thicker for the bell housing cooled slower than the rest so this caused it to crack..oh, and the insctuctions said to put an asbestos blanket over the weld immediately after to allow it to cool slow and even...Well I didn't have one so I played my odds..and lost.

But the good news is I have another block I will be picking up with a crack in the same place and we are going to try it again on an engine stand and follow the instructions to the letter..

More good news, I pondered should I just weld up the new crack and risk more cracks or use the crowd favorite as a test, JB Weld. I went ahead and beveled the crack and cleaned up everything and put a liberal coat of JB Weld on....I figured if it doesn't hold I can always grind off the JB Weld and try welding it again.. As of now it is holding like a champ.. I let it run for a while last night, and ran it to the gas station and it isn't leaking a drop... I am sure time will tell, but as long as it holds until I can get the other block here and repair it right I figure it is worth it to try..

I will try to remember long term updates to see how it is going...



http://www.texasoffroad.net/galleries/ohv/album290

[sha_ba_do_bang]

So he stick welded it? Damn, definatly some skill there, i have welded lots of cast things with tig and preheating the metal, the filler rod is also alot less expensive and the results look better.


Brendan