Olympia Cremina header wrap the boiler

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Dev

#1: Post by Dev »

My 81 Cremina that I rebuilt a few years ago is going strong. I plan to service the machine like I do every year around this time.
I had this idea of wrapping the boiler with some left over exhaust header wrap made with pulverized lava rock in the woven cloth to keep heat in. I know this machine originally came with an asbestos coat which I removed during the rebuild so I think this wrap would be beneficial to warm up times and reducing radiating heat from the boiler that could deteriorate the wiring over time.

Just looking for opinions if this would be a bad or good idea. For automotive use it can be a bad idea resulting in cracked headers but not always as it depends on the header construction. Since the boiler originally came with insulation at the time I thought it would be beneficial for what ever reason Olympia engineers used it in the design.

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baldheadracing
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#2: Post by baldheadracing »

I'm not sure about header wrap being as effective as other insulation like Insul-bright that has a reflective component, but if you have extra header wrap then probably no harm trying.

I can't imagine that the more modern wraps like DEI 'Titanium' would do much. The older kind that you dip in water when applying might be better (as boiler insulation, not as header wrap).

Geez, I just realized that the last time I wrapped/re-wrapped my exhaust was pre-pandemic. Time to add another task to spring car prep ...
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

Dev (original poster)

#3: Post by Dev (original poster) »

DEI Titanium wrap is exactly what I will be using. When I added it to my header it lowered under hood temps in the engine bay significantly since the exhaust components are on the opposite side of the firewall facing me since it's a transverse mid-engine roadster.
I think the best way to know its effectiveness is to record the before and after heat up cycling times. If they are wider then it was worth doing.
I have noticed that when the Cremina is first started it takes longer than I would like for all of the components to heat up and stabilize from when I pull a shot even though I do half pumps. Also the steam is not as dry. If I leave the machine on for 45 minutes the machine will produce dry steam for better froth quality and the shots will be better. I think by adding insulation I can lower that time as the machine was designed with the asbestos coating that most owners have removed.

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baldheadracing
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#4: Post by baldheadracing »

One way to measure effectiveness is to measure pressurestat cycling times, e.g., A little note on boiler insulation in the Olympia Club

FWIW, I did not see a significant reduction in total warm-up time after insulation, as the heat lost by the exposed group and hydraulics are a big factor. However, that result may not be applicable to the Cremina. The Club (and Strega and Lapera) have heavier groups than the Cremina, and also horizontal rather than vertical boilers. (Time-to-dry-steaming was improved.)

DEI wrap is good stuff but is meant for much greater differences in temperature. How one insulates a pipe running 1000F+ over ambient temperature is not the same as a pipe(boiler) that runs 200F over ambient. The DEI will work so I would try it; there are just other materials if one was starting from scratch.

As an aside, if you have any DEI Reflect-a-Gold or similar - the stuff that you'd put on your firewall to reflect heat - then, at least in larger levers, putting that reflective tape on the inside surface of the case helps. I don't know if it will help on a Cremina.
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

Dev (original poster)

#5: Post by Dev (original poster) »

Thanks, that was very helpful and informative. I am going to test before and after as you have. You make a good point on the benefit of extending the pressure stats life. I dread the day I have to replace it with a runaway MATER pressure-stat like I had on my previous LP.
Good to hear improvements in dry steam times as that would make it worth it if it shows some improvement.

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JohnB.
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#6: Post by JohnB. »

I've seen good results insulating steam boilers with foil backed ceramic wool insulation. P'stat cycles were extended over 40% on my old Vivaldi S1. Picked up well over a minute with the Bosco.
LMWDP 267

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bostonbuzz

#7: Post by bostonbuzz »

It would help insulate for sure. I'm not sure it's worth the fiberglass hairs going everywhere. I just did some insulation research and settled on some Cabot Aerogel Thermal Wrap TW800. Wrapping the 8mm three times will be almost an inch and be an R-value of ~7. I haven't installed it yet. That would outperform anything besides other dustier aerogels and vacuum insulation panels which would be impossible to install on a boiler since you would need to cut them.

That should majorly cut down on your electric use if you keep you machine on all the time or for many hours. It won't make a big different on heating up, though. The cremina doesn't really thermosiphon like other machines so I don't think you will loose massive heat through the grouphead. As I recall you needed to do mini pumps to heat up the head before a shot, and then go out of your way to cool the head between shots (even with a teflon grouphead gasket).

As someone else pointed out, your machine is a 100% efficient ~100W space heater as well. 100W counting the +1000W element being on a few seconds a minute. :D
LMWDP #353

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baldheadracing
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#8: Post by baldheadracing »

Dev wrote:Thanks, that was very helpful and informative. I am going to test before and after as you have.
I'll suggest avoiding my mistake and comparing:
- before insulation, with the case installed;
- before insulation, with the case off;
- after insulation, case off: and
- after insulation, case on
I didn't measure the first situation and so I can't estimate the full effect.

For the dry steam, this is related to horizontal vs. vertical boilers - the topmost parts of each. It is harder to do all the cutouts to insulate the topmost part of a vertical boiler so manufacturers don't do it. IIRC, asbestos covered the top of the Cremina boiler, so I'd say that you'd want to do the same.

Good luck!
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

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JohnB.
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#9: Post by JohnB. »

It's ceramic wool not fiberglass and there are no hairs going anywhere. It's a product designed for boiler insulation unlike a lot of the stuff I see guys using on here. All seams are sealed with metal heat tape. No issues (and no hairs!) in 9 years.
LMWDP 267

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bostonbuzz

#10: Post by bostonbuzz »

Sorry, that was directed at OP who mentioned fiberglass header wrap, which I have used (on a boat) and released so many fiberglass hairs my hands hurt for days. Wear a full face respirator when working with the stuff.
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