Paul,

There was recent mention of this in another thread. Always best to consult with the tester that you propose to use for your boiler (they will likely want to see it during the stages of construction anyway if they are following the code precisely) but I think it unlikely they will want to see certs for the copper. If they do you could ask how many ME suppliers of materials provide these for copper as a matter of course! It's only really relevant for copper if you are TIG welding it to determine the arsenic content. Steel is a different matter.

Paul.

Paul M – I believe this is the relevant part of the current 'Orange' Book (Vol1)

7.4 The Inspector shall satisfy himself:

a. That the materials used are of adequate thickness and the correct specification.

b. That, where required by the build procedure, the relevant material certificates are provided.

c. That the boiler is constructed in accordance with the design drawings.

d. That the requirements of Paragraphs 5.1 to 5.4 have been met. e. That all joining procedures have been satisfactorily undertaken and that the joints are sound. Particular attention should be paid to the penetration of silver solder and the adequacy of any welds.

For a conventional silver-soldered copper boiler being built to an accepted (e.g. known) design – personally I would want to check that the material was of suitable thickness and that the builder understood current boiler construction & test requirements. Provided I received assurance that the materials had been sourced from a reputable supplier – then I personally would be happy to agree the next build stage and schedule further inspection & tests. However, another Boiler Inspector may take a very different view and my opinion might not be held by others. Interpretation of the codes can vary.

The best advice is always to go and talk to your Inspector and seek his advice and guidance.

Regards,

IanT

Hi All,

Get your brazing torch too near to some of the cheaper grades of copper and it will crack. This is caused by oxygen in the grain boundaries of the copper being converted to steam. It cannot escape and the copper fails.

It is referred to as "hydrogen embrittlement".

Avoid the risk.

USE OXYGEN FREE COPPER

Alternatively you can always blame the flux, the torch, the gas or even the silver solder!

Regards

Keith

Paul,

I don't believe that you will have a problem if you go and speak to your local club inspector. You sound like you have done the best you can to control the materials etc. I suspect he will be more interested in the bush materials and the silver soldering stages. Also, please check your drawing. Many of the old drawings use threads in the plates for longitudinal stays instead of bushes. These features might catch you out.

If we start with material certification, we are heading for a minefield that you simply won't get out of e.g., most ME suppliers won't have proper QA, most self builders live at home, with a home workshop and no QA department?? Even if you had certificates, there is no guarantee that the parts are made from the same stuff. The QA issues go on and on and on and never end.

Phil H

Forgot to say that the good thing about c of c is full traceability right back to the foundry that made the material so it can be tracked to a large stockholder who sold some on to a smaller stockholder who sold it to the bloke you buy it from, traceability provides countless jobs across various industries and is essential fo medical and aerospace companies, but not for model engineers!

Paul,

Personally I would be very happy to view copper purchased from AJ Reeves as being from a "reputable supplier" – and I'm sure that there must be many engines still in service that have boilers built from materials supplied by Reeves at that time. I currently own four boilers, two built/tested & two unfinished – but I didn't purchase any of the original copper material for them – so I do not know what grade of copper was used and frankly I'm not going to worry too much about it either – at least as far as existing boilers are concerned.

Showing my ignorance perhaps – but I was not aware of the 'Oxygen-free' issue before reading Keith's post. I don't think I've seen this mentioned anywhere in any of the usual texts on the subject. Nor did it come up at the SF Boiler Inspectors Seminar that I attended a year or so ago (at least as far as I can recall – there's certainly nothing in the design notes provided).

However, if I were to purchase copper for a boiler in the future, it would now be something I'd certainly ask about. Whether Oxygen-Free is a real problem in actual model boiler practice, I'm not qualified to say. Nor do I know if there are cost implications in specifying O-F copper. Copper isn't exactly cheap whatever you buy.

However, we can speculate endlessly here about the suitability of your materials. Go talk to your Boiler Inspector and see what he (she?) thinks – then the two of you can agree the best way forward.

Regards,

IanT

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I've always believed that C101 was only a possible problem with oxy-acet, and then only if overheated.

Brian

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