Cracked block repair failure

"the WELD bead developed tiny hairline cracks"

Exactly. That is what usually happens. The crack will reappear along the original fault line.

I have never seen a cast welded part hold up. On the other hand, I have seen brazed cast repairs do well, if the brazer knew what he was doing. This synchronizes with Purdy's experience.
 
Thanks Tbird for the mention. I have had good luck with cast iron repairs with brass under the conditions that I mentioned in other posts on this thread. I have never tried a ni-rod weld on cast iron. I did have a head welded with ni-rod on a 21 stud flat head by the welding instructor at technical college and it failed just as you describe above. This was in 1965 and I have avoided arc welds on cast iron ever since.
 
Unfortunately another Model A block is damaged by a overzealous welder.

First picture is of a Pierce Arrow cylinder head that was brazed.
We had to cut out the marginalized areas and make pieces and stitch them in.

Second is the before and after of a Continental fire engine that may be similar to the initial posters weld.
Since it was welded cold with nickel rod it had small fissures along the welded area. basically damaged the block beyond the initial crack.

We again cut out the welded area and made a piece and stitched it in.
both of these vehicles are back on the road again thanks to metal stitching.
http://www.jandm-machine.com/metalStitching.html
 

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How much JB weld will this require:eek::eek:
 

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Here's the repair. Replaced the rod and all is well:)

Sewall
 

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For what it is worth and sort of on topic, 47 years ago I snapped the jaw off my vise. I had a AC arc welder, went to the welders supply store and asked for help. They sold me some NI Rod and told me to vee it out, preheat it and don't let it cool down too fast. They also said to be successful I would have to peen it between layers of weld and after finishing the welding. I used the flux/slag removable hammer I used to clean up my steel welds. That vise is still in use today and may be stronger than it was when I snapped it off.

No I have never welded a block, have had some done for me with great success but I am thinking that I might try that Muggy Weld product myself!
 
Well, covering all bases I used Irontite from Snyder's (while draining it I noticed it sealed a crack in the cement of my driveway) in addition to covering the bead with JB Weld.

I'm not too sure which one of them worked but my club had a 37 mile tour today and I made it there and back again with no problems.
 
Ive written about this before on the forum but I dont think anyone believes me:- Many years ago the company I was working for sent me on an advanced welding course run by the Castolin Euctectic institute. The Tutor was an elderly American. On the last day of the course he presented a handy hints lecture. It was then I learnt that you can solder cast iron. You clean up the surfaces ( lightly vee thicker sections) to an almost shiny state and treat with a strong solution of copper sulphate. When washed off this leaves a residue layer of copper on the surface of the cast iron. Then tin and run solder as you would to steel. This is a great repair method for cracked cast iron kettles cooking pots and anything that does not get to a temperature far above boiling point. It would work well on the cracked water jacket at the beginning of this thread especially if it had been carried out first and it is excellent for blocks with rods out the side especially if you have all the bits. Just solder it all back together sand it up paint over and no one would ever know. If you dont have all the bits make a few steel ones to fill the gaps.The advantages of soldering is it does not require high temperatures so you do not get the problems of thermal shock which causes cracking etc. Incidently the American tutor had been very popular up in the islands with the island ladies when he used this method to repair their kettles and cooking pots. Happy Motoring.
 
Anyone know where I can get the tapered screws that have a square head and pipe threads used for cold welding or stitch welding?I use to get them at NAPA but checked a local store and he said the one I went must of been an independent owned and had access to other stuff,also the name of such a screw,I saw them on the Internet lately but can't remember where . Thanks
 
Being a Ol Radiatorman, In the old days. You would warm up the car, then put about 4oz or half a cup of coffee of Sodium Silicate (water glass) in the radiator. Put cap on and drive it. As soon as it hits the air it solidfies. Worked on MANY cracked blocks. You can buy it at any drug store.
 
As each person responds with their own variation & solution to repairing a block, I was recently put into this position when a good meaning friend :(
decided to help me out by moving a bare block that I had set on top of 2 milk cases so I could tap out the head stud holes and do some cleaning............
His helpfulness knocked the block over and it landed on the R R corner, breaking it in several places & several pieces. I was not happy with him to say the least! I've welded (or so I thought) for over 50 years, and 8 years ago I went back to a trade school to learn how to TIG and also properly Mig
weld (actually its Mag, but thats) and my teacher turned out to be a cool car guy. His explanation is more or less what I did here. I positioned the block in a way that gave me access to the majority of the cracked areas & pieces I had to replace. I formed a makeshift cover / shield that surrounded the top of cylinder # 4 but would still let the heat escape. I then placed a commercial style heat gun below cylinder #4 in the crankshaft area and turned it on high for about 2 hours - the front of the block became uncomfortable to touch and the back corner needing repairs was slightly smoking. When ready to "braze" the repair, I had my ex-friend hold a propane torch below the repair area on the outside of the block below the water passage to increase the amount of pre heat, and I then began to braze the patchwork back into place. Once all the pieces were assembled and their corners were just the slightest bit tacked, I took a 2" disc grinder and cleaned off any of the slag / flux from the braze. With the edges of each piece ground prior to brazing, I was able to flow a beautiful bead along each of the multiple cracks & pieces until it was completed. Once finished, I put everything away, cleaned up yet left the heat gun on high for about 1 hour, then turned it down to low for about 2 hours, then turned off the heat gun and set a small space heater in front of the repaired area and made a small tent out of some sheet metal and left that run till I went to bed. The repairs came out fantastic :rolleyes: and dressed down to a point that noo one will ever know. I just got the block back from another 'good' friend that decked the top of the block for me and it looks perfect. I can look down into the water jacket through the corner water cooling passage holes
that the head and gasket mate up with and the repairs look clean and solid and flowed well with great penetration at the joints. It was a learning experience, and I still have a spare block for sometime in the future.
 
It is very important to locate the ends of the crack, and drill 1/8 inch diameter crack stop holes. The stop holes change the crack from a relatively fast growth to an infinitely slow growth.

Every crack has a tension stress field across it 90 degrees to the crack direction, so it should have a doubler to carry the tension over the crack. Otherwise the crack will recur.

The doubler material should have a coefficient of expansion the same as or close to the gray iron cylinder block. Make the thickness of the doubler twice that of the block. Weld the doubler into place.

Use Barr's Stop Leak to seal the job.
 
Skeezixx said:
I bought a 31 Coupe abandoned project expressly for the rebuilt (in 1986) engine sitting on the stand with zero miles which I installed in my roadster.

I managed to put 511 miles on it when, on a recent tour, an old JB Weld crack repair failed revealing a 4" long crack in the outside water jacket.

I took it to a local industrial machine shop where they welded the crack but the weld wound up with tiny hairline cracks in it. I spread some J B Weld over the length of the weld but don't have a lot of faith in this. Should I also use some sort of engine block sealer.

Or am I looking for another block?

Any suggections?
Click to expand...

I'm so sorry to hear about your troubles. I had similar frustrations last year. I ended up having to get a new block. Let us know what solution you find.
 
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