Randy G. wrote:Anyone who would use J.B. Weld to repair a boiler is liable to do anything, like repair a burst heating element with bailing wire or make gaskets out of cereal boxes.

Are you suggesting that those things are bad?

First of all, thanks for all of the replies!

That is the machine, mine is brown. Everything else is actually in good shape. It is clear someone tried to do a poor restoration on it before the guy I bought the machine from sold it to me. I take partial blame as I should have seen the jb weld on there from a previous repair. I will speak with him and see what he would like to do. I buy a lot of machines from him so we should be able to work something out.

Thanks for all of the advice! I plan on doing a full restoration as well as giving it some new powdercoat. I have yet to decide what colors I am going to go with, but will post a writeup when I do!

You are all the best!

Okay... I am going to say:

1. Metallic Black Cherry
2. Metallic Brandywine Red

I know, Iknow... you did not ask...could not help myself.

It's hard to imagine how/why the boiler's seam joint has failed like that, and that might lead you to want to examine it closely for further faults.

Personally I'd be investigating a TIG brazing process with silicon-copper to braze a stainless-steel patch over the fault (the boiler is stainless isn't it?). Challenge though would be finding someone with the specialist skills do this if you've not yourself. There are so many different welding processes out there and some like TIG brazing are not commonly used - it might be hard to find someone in general industry who does it, and who you can trust to advise what process and filler alloy would be best suited.

Here in the UK from time to time I deal with boiler makers in the heritage steam-locomotive world. The guys in these circles are absolute craftsmen and build boilers that run at 9bar compared to the typical 1bar we deal with. They use processes not typically used in industry nowadays and can often help out at reasonable cost.
http://www.swindoncopperboilers.co.uk/
http://www.ptmachining.co.uk/
http://www.maidstone-engineering.com/bo ... el-boilers
http://lamb-engineering.com/

Find someone like this in your region and you might be onto something. Perhaps post a classified add onto something like
http://www.model-engineer.co.uk/ asking for machining or boilermaking services - I was surprised to find all manner of very capable modellers who were happy to earn a bit on the side. I now can't justify buying myself a metal-lathe.

Otherwise as has been eluded above it might just be less hassle to buy a replacement boiler - you'd likely then only be dealing with adjustments to connecting pipes.

Check the OPV. A boiler blowing up means the thermostat and , the safety thermostat (if exists) and safety OPV failed.

Or it was dropped?

AssafL wrote:Check the OPV. A boiler blowing up means the thermostat and , the safety thermostat (if exists) and safety OPV failed. Or it was dropped?

Those are only 2 less likely causes - there are many more. This could have started as an internal flaw in the metal (an invisible defect in the crystalline structure of the metal that's undetectable without very specialized ultrasound, xray imaging etc). It's why a seemingly perfect bolt or hard part (e.g. a stub axle) cracks for no apparent reason.The stretch-relax effect of repetitive heating-cooling cycles can propogate a microscopic flaw into a crack over time because that very tiny irregularity is what's known as a stress riser. The irregularity "concentrates" internal stress at the flaw and it eventually becomes a crack. These internal flaws are simply random results of the physical processes of manufacture - casting, rolling, heating, cooling, drawing, bending, etc. Forging has a lower rate of flaws because the pressures and temperatures favor homogeneity in the metal. Almost every ordinary cast metal piece has many, but they're usually of no consequence and are never detected.

Someone could have put cold water into the boiler while it was hot, or abused it in many other ways (e.g. your example of dropping it, although that would almost always cause visible deformation as well). Another common cause of embrittlement of metal is poor workmanship during attempted repair. Metal has to be heated, cooled and handled properly - some will harden from air cooling and be crack-prone without normalization / annealing / etc. Taking a torch to a boiler (or any other metal object) without knowing exactly how to carry out the intended repair (or if it's even reasonable to attempt) and how to properly treat the piece during cool-down is a common cause of subsequent failure.

My guess would be that the original weld/braze was poorly done and that a qualified expert and testing would result in a good repair.

bluesman wrote:Those are only 2 less likely causes - there are many more. This could have started as an internal flaw in the metal (an invisible defect in the crystalline structure of the metal that's undetectable without very specialized ultrasound, xray imaging etc). It's why a seemingly perfect bolt or hard part (e.g. a stub axle) cracks for no apparent reason.The stretch-relax effect of repetitive heating-cooling cycles can propogate a microscopic flaw into a crack over time because that very tiny irregularity is what's known as a stress riser. The irregularity "concentrates" internal stress at the flaw and it eventually becomes a crack. These internal flaws are simply random results of the physical processes of manufacture - casting, rolling, heating, cooling, drawing, bending, etc. Forging has a lower rate of flaws because the pressures and temperatures favor homogeneity in the metal. Almost every ordinary cast metal piece has many, but they're usually of no consequence and are never detected.

Someone could have put cold water into the boiler while it was hot, or abused it in many other ways (e.g. your example of dropping it, although that would almost always cause visible deformation as well). Another common cause of embrittlement of metal is poor workmanship during attempted repair. Metal has to be heated, cooled and handled properly - some will harden from air cooling and be crack-prone without normalization / annealing / etc. Taking a torch to a boiler (or any other metal object) without knowing exactly how to carry out the intended repair (or if it's even reasonable to attempt) and how to properly treat the piece during cool-down is a common cause of subsequent failure.

But would all of those result in such a long crack along the weld joint? Also, these boilers are supposed to be tested at 2x pressure if not more.

Edit: In any case, my point was to test the safety devices, and if in doubt, replace them. Perhaps they didn't fail. But maybe they failed to do their job.

bluesman wrote:Those are only 2 less likely causes - there are many more. This could have started as an internal flaw in the metal (an invisible defect in the crystalline structure of the metal that's undetectable without very specialized ultrasound, xray imaging etc..

I think we have a staff metallurgist. Being a bluesman doesn't hurt either!

I once brazed a socket to the open end OF A 13mm combo wrench to make a 2-in-one bicycle tool. After brazing I dipped it into water to quench it. On the first try to tighten a crank-arm bolt on my road bike the socket split and looked like an opening daisy flower. After the wound across my wrist healed I tried again, but this time I used occasional sprays with misted water from a pump bottle till it cooled. I told a machinist friend about my experience and he replied, "Congratulations! You just invented metallurgy!"

Two lessons learned -

1 - Always put the chain on the outer chain ring before attempting to remove a crank arm bolt, and
2 - There are a lot of ways to deal with metal. Some work far better than others. Sometimes it is a good idea to consult a professional.

Could the machine have frozen with a full boiler?

If that's the case, there's probably damage elsewhere.

Agree with the folks who say the boiler is scrap, regardless. Just for starters, how would you know you've eliminated all the JB Weld? I don't think it's food safe, least of all at extreme temperatures.