I was wondering if folks would provide some input about the cast welding technique shown on this link http://www.youtube.com/watch?v=Yopcz-IYDyQ I want to give this a shot on the 409 crack shown below (Not good - I know) Additional questions: Is it wise/unwise to torque down the head prior to welding? If this weld fails is it likely to warp or otherwise damage the head (if fails after assembly)? If the weld fails is it still repairable by someone else? This concept seems to make sense to me - any input would be greatly appreciated. Thanks...............Cracked
So, are you going to be repairing an old I-H trans housing that is of little/no value, (with a "simulated" crack) or are you trying to save a 409 block? Find someone with an oven and knows how to braze!!!!!!!!!! Do the repair then surface the block.
Don't think it's time to experiment. Pre heat is done for a reason. also good idea to drill each end of the crack so it doesn't grow while your welding
Have the block maged and checked for other cracks that aren't visible to the eye before you do anything. Would not do much good to respiration that crack if there are others in hiding. Curious, did you contact locknstitch? If so what did they say?
We gave you several excellent answers to this question last week and I think if you go back and read them you can get excellent results. As to preheating before welding, yes pre heat the block to avoid any thermal shock. Cast iron is prone to cracking so you want to do everything possible to help your weld process.
I think everyone is telling to to DO IT RIGHT and dont look for the cheap and easy fix...... its not there.
As the other posters have stated, the heating prevents the stress cracks, and the slow controlled cooling prevents another large crack from happening. Bob
409, take 5 minuets and check out a site, www.lock-n-stich.com. They have a couple videos that you should take the time and watch. Thermal shock and expansion rates are discussed and are critical to welding cast iron.
This looks like the 3rd time you have asked this in the last week!?!?!?! Sounds like "ask questions until you get the answer you like"
Bolt a torque plate or suitable substitute down at least on the ends. The weld will shrink and pull as it cools. I can't comment on the video because I've not personally done that on anything I cared about. I've shot plain mig on ice cold cast iron before because I didn't have a choice and it needed to last just a few mins/hours. Held fine for what I needed. Welded plenty of cast iron and can't recall ever having an issue other than one time. That one time was applying a hard face to a 6' diameter bell valve. We thought we could save that piece and give it some new life as well as add to the expected service life of the unit. Didnt work and cracked. Everything else was heated, welded, reheated and cooled slow.
^^ No the op asked a specific question about using a specific repair method. If everyone would focus on that. It would not be a repeat thread. Sent via Illinois Bell Telephone Company's Car Radiotelephone
Low amps, crappy welds with minimal penitration, not even a crack in the first place, no pressure testing of any type? I want my 10 minutes back
Repairing cast correctly is a crap shoot even for a specialist. I have a person that fixes $10, 000 gearboxes and he is worth every penny he charges me. A poor repair attempt by myself would end up costing me thousands.A failed attempt might make block non repairable.
Back Steeping is not new and a good idea anytime you want to control heat or warpage. I would still pre heat and also peen and control the cool down. Just me! I am a retired welder.
Wait I think I have the answer he wants, it was told to me by an oldtimer when I was young and thought that everything could be fixed. His quote when I asked him about something like this was " I can just pull my magic wand out of my butt and wave it around and fix it for you. No charge!" He was a bit more colorfull, i cleaned it up for the proper people on here.
Cracked 409 Block, you may want want to read this thread. http://www.fordbarn.com/forum/showthread.php?t=122495 It deals with a pan rail crack on a Ford flathead block. It might apply to your situation.
Installed a rat motor in a 61 C-10 long ago. Exhaust manifold room was very tight, bought a couple new corvette manifolds from the dealer and proceeded to slice and dice them to clear the frame rails had to extend the pipe flange on the starter side with a piece of iron pipe. Got it mocked up, held together with tape, mill wright @ the can plant welded it up with nickel stick, came out perfect and held up for years. Seen a lot of cast welded up with nickel stick. Think I'd stitch that 409, on the other hand don't know if I'd bother, pretty bad place for a crack.
Not all cast iron is equal, exhaust manifolds have a lower carbon and silicon content and are easier to weld up.....High carbon high silicon stuff like blocks and heads as well as thin castings are a bugger to weld...
Question came up recently about me welding a new mounting flange on a F100 steering box. I didn't feel good about doing that but I know it has been done a million times. My concern is more with warpage and distortion where bearings and seals are located. Thoughts?
Thank you 1955IHC I was indeed trying to get input on a specific technique With all due respect - I have heard pinning is the way to go - no pinning will not work in that location Weld it this way - no you have to weld it this way........... I do appreciate all the input - the technique does seem to make some sense but I also can see how it might not work. Ultimately I need to evaluate all the options and decide - and it scares the heck out of me - I am just trying to feel comfortable with whatever I do!!
I'm only an amateur welder but I have tried to weld cold using short bursts and still had it crack as it cools. In the video there is no crack to begin with to instigate further cracking at the weld. Maybe the air gun peening helps but I'd be damn fast at it.
Cool down is also very important when welding cast iron. We had a tub filled with (please no EPA comments) asbestos flakes and anytime we welded anything cast we would bury it in the flakes after the weld process. It's amazing how long it held the heat in. We did a huge gearbox housing one afternoon and in the morning it was still warm!
As posted previously. That youtube piece has little to do with a real crack. The guy is just adding material to the surface of the part. A different situation entirely. I have repaired tractor blocks, out in the field, with a Mig loaded with "easy grind" wire and also used silicon bronze wire. Short weld, lots of cool time..Watch polarity of machine.. I have been schooled in the lock/stitch method by the company and have used the method many times. Tho I prefer heating and bronze Mig. There are several grades of nickel rods. So that has to be addressed also..
That is a very misleading video. He admittedly makes a poor weld and then keeps on going as if all is well.
I'm glad I didn't work in that shop! Asbestos dust and snow, yeahhhh! Dry Sand, vermiculite, fiberglass bats that you use in your attic, BBQ grille, to name just a few , there's sooo many other things and ways to extend the cool down.
The Jalopy Journal
