Ugly-looking CMA boiler--really a problem or "they all do that"?

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amb
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#1: Post by amb »

First off, my apologies for the cross-posting if you've seen the first part of this before elsewhere; when asking elsewhere I got a bunch of feedback that this was the right place to be asking about this class of machine, and based on some time reading here I can see why!

I have a new-to-me CMA (Rio) SME/1N JUN that seems to mostly be in good shape but on which the right-hand side of the boiler looks fairly bad, in particular the brown... stuff (growths? deposits?) next to the sight glass guard. The boiler holds pressure, but I'm wondering if this is a sign of pinhole leaks and impending doom, or whether I should clean the machine up and get on with life. (I can read manuals all week, but this one needs a bit of judgement!) Anyone?

Also, thanks to all of you that have posted the amazing and picture-laden threads on rebuilding your CMA machines; I got this machine almost on a lark (one of those "right place at the right time" deals), but I think it's a keeper, and it's nice to see what I'm in for if I do end up doing a complete teardown. (Actually, most people seem to be dealing with SAE/1N machines instead of SME/1N, but I haven't noticed the difference. Do this acronyms actually mean anything?)

Thanks for any clues/advice/observations/mockery/inspiration!


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Chert
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#2: Post by Chert »

Although I've not been around enough commercial machines in prolonged use to be very knowledgeable, I think there has been some leaking water from the fittings. The streaks of deposit seem to be concentrated over those boiler and sight glass lower fittings. I would think some vapors escaping from the fittings then deposit the schmutz you see along the seam of the boiler and above the other fitting. Is the inside of the boiler laden with similar deposits from the water that was used?

Hope this helps. I'll be interested to see what others might add.

BTW, What is the material fitted behind the sight glass? I want to contrive such a thing for my ongoing CMA restoration.
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Randy G.
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#3: Post by Randy G. »

Chert wrote:Is the inside of the boiler laden with similar deposits from the water that was used?....
I recommended pulling the heating element in the other forum where the OP placed a similar post with the same (but smaller) image.

It does appear that it is leaking fittings over long term and not boiler leaks, but further investigation is certainly warranted.
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amb (original poster)
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#4: Post by amb (original poster) »

Randy G. wrote:I recommended pulling the heating element in the other forum where the OP placed a similar post with the same (but smaller) image.
Indeed, HB has much more useful limits for image size! (Also, thanks for the recommendations in both cases.) I've attached the element picture (though it's not inline) in case it's useful, but it looks just like a heating element should, I believe. (The element itself looks great to me, with just a bit of wet loose scale picked up from the gunk at the bottom of the boiler as I took it out.)

The boiler looks less good, but maybe not disastrous:

Getting in there for pictures is a bit difficult; sorry about the quality. From where things are now I can easily enough vacuum out the main boiler, but if the heat exchange chamber is also likely to be crudded up I may as well have it all out now and turn this into yet another CMA rebuild thread. :) From my explorations of the solenoid area I'm already planning on having the group out for cleaning, so I've given up on having this in operation in the immediate future.
Chert wrote:Although I've not been around enough commercial machines in prolonged use to be very knowledgeable, I think there has been some leaking water from the fittings.
The machine is basically also open on the top aside from a grating, so if the previous users were in the habit of putting wet cups or whatever up top to warm, it would all also be dripped down into the works.
BTW, What is the material fitted behind the sight glass? I want to contrive such a thing for my ongoing CMA restoration.
It's enameled steel, I believe. I'd first taken it as a stock part, but looking again it's clearly a somewhat sloppy but surprisingly useful retrofit that happens to wedge into place nicely. Here's a picture (again sub-par, I'm afraid) of it from the front; note that unused screw holes that were clearly intended to mount it on something else:

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Randy G.
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#5: Post by Randy G. »

amb wrote:The machine is basically also open on the top aside from a grating, so if the previous users were in the habit of putting wet cups or whatever up top to warm, it would all also be dripped down into the works.
I was thinking that very same thing when I saw the first images you posted!

The boiler does not look bad at all. I have seen pics of the so scaled that they look like they were filled with concrete and then drilled out with just enough room to slide in a heating element (I think Barry J. posted one like that a long time ago).

I think an external clean up of that crud on the boiler and a good descaling is going to be a great start. If you have the time, removing the boiler for a hot descaling dip would be good. That would also allow you to clean up all the fittings to assure a leak-free(ish) installation.
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HB
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#6: Post by HB »

Sorry for this brief administrative message:
amb wrote:First off, my apologies for the cross-posting if you've seen the first part of this before elsewhere...
Randy G. wrote:I recommended pulling the heating element in the other forum...
As you gentlemen clearly recognize, this site strongly discourages cross-posting. However, it's not a problem if you're not getting answers to your questions elsewhere, as appears to be the case here. Once you've made that determination, feel free to link back to the original discussion should others wish to follow the "bread crumb" trail.

So, for those wondering about one of the "other" discussions Andrew and Randy mentioned, see Bitten by the HX bug--but was it poisonous? on CoffeeGeek.
Dan Kehn

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cannonfodder
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#7: Post by cannonfodder »

I agree with most here that the machine has leaking fittings and is in bad disrepair but what concerns me is the scale on the left side of the boiler at the weld seam. If it was dripping water it would run to the lowest point of the boiler (bottom or a fitting) then dry and crust over time. The large deposits on left side right at where the water line in the boiler would be look to be boiler leaks. If it was dripping water, the crust would not be growing horizontal but vertical. That looks like a pin hole leak and the scale grows out from the pressure of the water. Could be nothing and simply a fluke, but I would inspect those areas very carefully. If you had a way to pressure test the boiler I would do that before spending all the time working on the rest of the machine. Pull the boiler, descale it which will take quite some time from the looks of it, then pressure test it to see if you a big door stop or a rebuildable machine.
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Randy G.
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#8: Post by Randy G. »

cannonfodder wrote:... what concerns me is the scale on the left side of the boiler at the weld seam. If it was dripping water it would run to the lowest point of the boiler (bottom or a fitting) then dry and crust over time..... If you had a way to pressure test the boiler I would do that before spending all the time working on the rest of the machine..
Good pull and excellent advice.
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amb (original poster)
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#9: Post by amb (original poster) »

cannonfodder wrote:If you had a way to pressure test the boiler I would do that before spending all the time working on the rest of the machine. Pull the boiler, descale it which will take quite some time from the looks of it, then pressure test it to see if you a big door stop or a rebuildable machine.
That's fair; thanks for the input. My irrational optimism (and perhaps laziness) aside, it's only a half-dozen more fittings, and a pressure test after that is easily done and should remove all doubt.

Based on other repairs I've seen here I'm hesitant to assign it doorstop status just based on boiler leaks, though. Actually, there doesn't seem to be much anywhere on these machine that isn't fairly readily repairable, though if the boiler needs repair I expect I'll be seeking professional help.

For reference, here's some useful advice on boiler repair in this thread, both some less-recommended but possibly effective techniques and suggestions for the right way to deal with it: Repairing leaks in a copper boiler