cracked block

[R.White]

Having stripped the engine for a re bore I noticed a rusty mark on the water jacket. Further investigation revealed a crack about 6" long. This would have happened before my ownership and as the area had been covered in grime and black paint I hadn't noticed it before.  The amount of water loss is not significant; no more than a slight weep but it will need attending to.  I enquired about cast iron welding with a local specialist and his recommendation over the phone was that rather than welding - an expensive process if the cast iron is not to harden - cold stitching the crack might be better.  This would amount to about £100 per inch.  I would have thought the position of the crack would make this type of repair tricky and if the specialist saw where the crack was he might change his mind and want to go down the welding route. 

 

There is another option. The system is low pressure and coolant loss is negligible so I am reluctant to spend large sums on this.   I know there are likely to be howls of ridicule but I have been looking into using an epoxy compound.  Of the many options on the market JB Weld claim their product is the strongest; their "high heat" having a bond of 600 psi at 204 deg. C.   However, I am not sure this is necessarily true.  I have been looking at a product called  Belzona 1111 Super Metal ; an epoxy composite developed for the Military and also used by Caterpillar which has a strength of 3,240 psi. at a similar temperature. Based on a silicon steel alloy blended with high molecular weight reactive polymers and oligomers to produce a high strength structural adhesive it is relatively expensive at £80 for 1kg.

 

I would need to grind out the crack along it's length with a 'V' or 'U' section to give the epoxy a bed.  Only time will tell if it is the right call. 

http://www.belzona.co.uk/ViewFile.aspx?id=52299    

 

I know that the crack should be stopped from spreading further by drilling a hole at each end but what I am not sure about is how deep to drill down.  If I go through the water jacket I fear I will be making a bad situation worse.  If the crack isn't stopped, however, I guess I run the risk of it getting worse. 

 

Ray.

Edited October 15, 2016 by R.White (see edit history)

[Reg Evans]

I had great success with a similar crack and JB Weld. No ridicule coming from my mouth.  I would sandblast the area though to get inside the crack.

[F&J]

19 minutes ago, R.White said:

 I would need to grind out the crack along it's length with a 'V' or 'U' section to give the epoxy a bed

Just me, I would not do a V or U.  I would use a die grinder with a thin cut-off abrasive wheel, to make the walls of the crack to be something like this: )(

 

That way, the epoxy "plug" cannot move out, or inwards.

 

I also would go with a product that does not get as hard as metal.  I would think the crack will flex during cold-to-hot cycles.

 

You have little to risk by attempting a patch job.  If it keeps failing, there is a special system that uses very bizarre threaded plugs that actually pull the opposite sides together, and this requires drilling larger holes that will go beyond any crack grinding you do try.  So, it's just a back up plan.

[Machinist_Bill]

Wow Ray! Don't you love all the surprises?  You are correct on drilling small holes at the ends of the crack. This eliminates a "Break" edge for further cracking. If the crack is all the way thru then you drill all the way thru.

  I have tried everything on cast cracks and all failed eventually. The reason why is because the heat causes the cast iron to expand and contract when it cools. To successfully repair the crack you need a filler that expands and contracts at the same rate as cast iron. All of the above products do not.

   I have heard of a process where the block is heated to approx. 1400 degrees and new iron is actually melted into the the bad area. It is then packed with K-Wool and slow cooled for about a week. This is very expensive and you could replace your block a LOT CHEAPER!

If all else fails find a good weld shop. They will pre-heat with a rosebud and weld with ni-rod. Be ready to pack with insulation and SLOW COOL. Any cool air will crack it faster than you can say WTF!

One more thing when you grind the cast where a respirator. Back in the day there was beryllium in the metal.......

 

Keep us informed Ray.

 

Bill

[R.White]

Many thanks guys.  Plenty for me to think about there!

 

 Seeing as I didn't even know I had a crack at all I can't see me splashing the cash on this.  The cast iron welding specialists close to where I live (there are actually two of them!) heat the entire block to a high temperature and slow cool like you mention Bill.  This is the expensive process that I was describing in my original post.  I questioned the specialist about the effects of heating cast iron because I feared it becoming very hard and difficult to machine.  They say their process avoids this problem but the guy must have been uneasy about my asking (they probably don't get many customers who raise metallurgical  questions) because he switched to the metal stitching process that I think F&J was alluding to.  

 

Good advise about respirator  when grinding cast iron.  Nasty stuff.  

 

I know what my father in law would have done.  He would have added 'rad weld' or 'Bars leaks' to the coolant and stopped up any leaks from inside.  The problem with that stuff is it can block up your radiator and that is something I am not prepared to risk.

 

The block on that side at that level doesn't get that hot does it?

 

Ray.

 

 

Edited October 15, 2016 by R.White (see edit history)

[ColonelDan]

When I was a teen, I used a product called Alumseal.  There is a sister product called Bronzseal made by the same company.  I don't know the advantages of one over the other and I think I've used both with equal success.  It worked great for me on all of the junkers I once drove.  Its a container of what looks like powdered Aluminum (or bronze) that is dumped into the coolant.  It is probably more complex compound than just powered aluminum but that is what it looks like.  The manufacturer claims it seals all leaks, prevents corrosion of the water jacket, and provides lubrication to the water pump.  I've seen it from time to time in automotive stores but have never had the need to purchase or use it since 1970 or so.  If it is still available, I think I would try it first.  And it it fails, go on to more expensive measures.

 

I just looked it up on the internet.  It is available for about $3.50.

[JACK M]

When I was a kid an old guy told me to go to a pharmacy and buy a quart of 'waterglass' and put it in the cooling system.

It worked well.

However as your engine is torn down I would probably lean toward some epoxy or the likes.

Being there is no pressure a patch like this just may work.

I recently pressure washed a slant six and uncovered a 6 inch JB Weld repair. It was working fine.

[R.White]

I must admit to quite liking the different solutions you guys are offering.  It would seem there are many, many choices which is at least encouraging.  As this old Dodge Brothers car is my hobby, I am a bit reluctant to hand all my problems with it over to someone else to fix but I do appreciate that without the specialist equipment I can't do certain things.  

 

Many years ago I remember my late Dad recounting how he repaired the block of his 1929 MG midget ('M' type UW 5990 where are you?) by using the "stitching" process.  He drilled and tapped holes through the crack less than a hole's width apart and threaded in brass studding.  After cutting off the studding he then drilled and tapped in between the two studded holes and threaded in more brass studding.  By overlapping and grinding down the brass studding in this way, a continuous metal seam replaced the crack.  He was so pleased with the result that, apparently,  it seemed a shame to paint over the repair.  I am toying with doing a similar thing but at the moment I am undecided.  

 

Presumably, brass will expand and contract better than epoxy? 

[MikeC5]

I suspect the crack was from water freezing and not just from normal heat cycling.  I like the JB Weld or maybe the Belzona.  In days gone by I had successful radiator repairs using JB weld.  I'm thinking the different expansion coefficients of cast iron vs. epoxy will not be that big of a deal since the temperature rise is only something on the order of 120 F or so.  If you can get to the inside (maybe sandblast?) I would patch inside and out.  I would stop drill the ends (through thickness) just to prevent it from growing.  Maybe 1/8" diameter (that's what I've seen used on some aircraft nozzle repairs).  I suspect the issue with welding and the need for slow cooling is grain size and martensite formation.  Fast cooling gives smaller grains which tends to make things less ductile.  It can also cause martensite to form which can make cast iron much harder but more brittle and susceptible to cracking.  Slow cooling (over a day or two) controls these factors.  More massive parts may need much more cooling time to prevent cracking; just from the cooling process inself.

Edited October 16, 2016 by MikeC5 (see edit history)

[22touring]

I know the conventional wisdom is that you cannot braze a crack like this; nevertheless, before I knew any better I did braze cracks like it and the repairs were successful.  Did I just get lucky? I would like your opinions.  Thanks.

[frankngin]

R. White's process was a lesion learned in Machine Shop class back in High school. Instead of small Machine screws we used tapered Cast Iron pins.

Frank

[R.White]

Hi Mike.  You are right it is a freeze crack but fortunately not much harm done.  I can find no evidence of a vertical crack or a corresponding horizontal one above it as you often get.  It's good that there is hardly any blowout and I have tidied up the little that there was.  I also have my doubts that heat would be an issue bearing in mind where the fault is on the engine but then again warming up on a very cold day might prove the nay sayers right.

 

I have pretty much ruled out welding of any sort on cost grounds alone!  

Brazing or any heat treatment on cast iron has the effect of hardening the metal making any machining more difficult if not impossible.  Cooling must also be controlled over days to avoid a shock that will make it crack again.  

 

If it was the only issue I have with the car I might feel differently but there is just one thing after another.  The collapse in the Pound has also made all imported parts more expensive.  All part and parcel of old car ownership!

 

Ray.

Edited October 16, 2016 by R.White (see edit history)

[F&J]

15 hours ago, R.White said:

by using the "stitching" process.  He drilled and tapped holes through the crack less than a hole's width apart and threaded in brass studding.  After cutting off the studding he then drilled and tapped in between the two studded holes and threaded in more brass studding.  By overlapping and grinding down the brass studding in this way, a continuous metal seam replaced the crack.

 

15 hours ago, R.White said:

 The collapse in the Pound has also made all imported parts more expensive.

 

I mentioned earlier about a bizarre threaded plug-stitching method.

 

This was explained to me by a guy who runs an engine shop.

 

He said the plug is very slightly tapered so it can be snugged up.  But the unique feature of the threads, is that a normal thread comes to a point at the outside.  These are reverse.  The root of the thread is the thin part, and it gets wider at the outside.  This pulls both sides of the crack together, tighter. 

 

He does a row of these not quite touching each other, then does the final row in between.

 

If two 1/4" plates were done with this system in a clamped position, the plates will stay together like a welded seam, when removed from clamping.

 

To finish it, they are ground smooth, then a needle scaling tool makes the patch look like cast iron

Edited October 16, 2016 by F&J (see edit history)

[R.White]

1 hour ago, F&J said:

 

 

I mentioned earlier about a bizarre threaded plug-stitching method.

 

This was explained to me by a guy who runs an engine shop.

 

He said the plug is very slightly tapered so it can be snugged up.  But the unique feature of the threads, is that a normal thread comes to a point at the outside.  These are reverse.  The root of the thread is the thin part, and it gets wider at the outside.  This pulls both sides of the crack together, tighter. 

 

He does a row of these not quite touching each other, then does the final row in between.

 

If two 1/4" plates were done with this system in a clamped position, the plates will stay together like a welded seam, when removed from clamping.

 

To finish it, they are ground smooth, then a needle scaling tool makes the patch look like cast iron

 

This is where I start to get outside my comfort zone.  Does the hole need to be tapped with a taper plug or is it straight?  Where do you get these tapered plugs from? 

[F&J]

30 minutes ago, R.White said:

 

This is where I start to get outside my comfort zone.  Does the hole need to be tapped with a taper plug or is it straight?  Where do you get these tapered plugs from? 

 

The special tap and plugs are part of a kit.

I did not ask what the trade name is, or the company.  I can try to find out but it may take a week.  It is the middle aged son of a elderly friend of mine.

 

The reason I mentioned this, is that if you try your drilling method first, then these plugs may be smaller that what you drilled, if yours fail.

 

I never followed up on these, because my freeze cracked 32 Nash head;.. the crack was down into one spark plug hole, and the other end went under the headgasket surface.  I was lucky to find a good used head on the "what is it" thread on here.  Took a few years of looking.

[R.White]

I found a company which specialises in metal stitching.  They would probably be too expensive for me.

https://www.metalock.co.uk/typical-on-site-repairs/metal-stitching.aspx

 

This U.S.A. company can supply kits but I expect it's overkill for me and what I need.

http://castingrepair.locknstitch.com/category/crack-repair-tools-supplies

 

Ray.

Edited October 16, 2016 by R.White (see edit history)

[F&J]

Reading all of your replies,; if it were mine, and had the same budget,,,, I would not pay the very high price of Belzona, and I think that product will harden far too much.  I would go with coarse grind at the crack for a good grip, and go with JB Weld.

 

I would do that first, rather than trying your own drilling system that may burn a bridge.  You can use that for a back up plan if the JB fails over time.

 

 

[platt-deutsch]

Water Glass solution was Sodium Silicate. May have ask for it that way now.

[JACK M]

15 hours ago, platt-deutsch said:

Water Glass solution was Sodium Silicate. May have ask for it that way now.

 

Good info, thanks.

[Guest Wayfarer]

Regardless of which repair method you choose, be sure to drill the ends; a crack in cast iron will continue to grow during any heating/cooling cycles.

I like your dad's repair.

[nearchoclatetown]

Water Glass is what was used in the cash for clunkers scam. 

[cahartley]

The best ever block sealer we ever discovered is KW Block Sealer.

[DCE]

Quote from above:

"I know what my father in law would have done.  He would have added 'rad weld' or 'Bars leaks' to the coolant and stopped up any leaks from inside.  The problem with that stuff is it can block up your radiator and that is something I am not prepared to risk."

 

Hello Ray,

I was advised by a technician/mechanic who worked in the Harrah's restoration shop for many years that they would always by pass the radiator during the process of using a block sealer.  He also indicated that sodium silicate provided excellent results.  

 

As well, youtube has some wonderful video on metal stitching.  Searching "lock n stitch" on youtube will list a number of very informative videos.  Best of luck on your repair.

DCE

[billstewart]

Hi, make sure you don't mix the water glass  with antifreeze 

On 10/19/2016 at 2:24 AM, DCE said:

Quote from above:

"I know what my father in law would have done.  He would have added 'rad weld' or 'Bars leaks' to the coolant and stopped up any leaks from inside.  The problem with that stuff is it can block up your radiator and that is something I am not prepared to risk."

 

Hello Ray,

I was advised by a technician/mechanic who worked in the Harrah's restoration shop for many years that they would always by pass the radiator during the process of using a block sealer.  He also indicated that sodium silicate provided excellent results.  

 

As well, youtube has some wonderful video on metal stitching.  Searching "lock n stitch" on youtube will list a number of very informative videos.  Best of luck on your repair.

DCE

 

Edited October 20, 2016 by billstewart
miss spelled (see edit history)