Newly acquired Microcimbali Liberty: had a few restore questions - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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PacMan (original poster)

#11: Post by PacMan (original poster) »

No, I didn't pay much for the Microcimbali, I never like paying list prices. What I am slightly upset at myself about was that the seller offered me a free second Microcimbali (vintage with chrome boiler) with a "busted boiler" for spare parts if I wanted it. Now that I think about it I think he meant that the heating element was probably not working. I passed on it worrying more about the clutter in my house than the need for parts. Must be some form of lever machine karma. Lesson learned. Never say no to a free lever machine.

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drgary
Team HB

#12: Post by drgary »

Duy,

Sorry for your mishap!

BTW, I got an answer to how to care for these aluminum boiler machines. It's on the tag they post on the front with operating instructions. Cimbali suggests emptying out the machine after every use.

Gary
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Carneiro

#13: Post by Carneiro »

But what about the humidity plus the O2 available on the air?

If an aluminum oxide layer is formed than I agree, the water left in the boiler could be bad to the layer. But maybe a bad pitted boiler doesn't form a good oxide layer anymore... I remember talking to a friend that is Materials Engineer and it seems the metal with pitting corrosion should receive some heat treating and that would complicate things...

Márcio.

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drgary
Team HB

#14: Post by drgary »

Hey Marcio,

I don't know the answer definitively. All I do know is from the experience of having old aluminum window frames. The part that was exposed to the outside would get wet, and that's the part that corroded. The inside part stayed dry and did not corrode. And looking at the outside of the boiler on the Microcimbali, there is no corrosion at all. I've just emptied the aluminum boiler in the Duchessa and will store it dry -- and unplugged!
Gary
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What I WOULD do for a good cup of coffee!

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drgary
Team HB

#15: Post by drgary »

Another note on the Microcimbali design. Doug (orphanespresso) wrote on another thread that the water tap on the bottom of the boiler appears to be designed to drain the boiler rather than serve as a hot water source, thus there's no wand. Here's a picture of that:



The water drainage port and the instructions on the base of the machine seem to be ways to sidestep the aluminum corrosion issue. OTOH Doug also writes in this thread:
orphanespresso wrote:No matter what you do the Micro always seems to maintain some water around the edges.
That suggests that draining the boiler may not be enough, and restoring these machines for longevity may be assisted with putting a zinc anode in the boiler water, if this doesn't flatten the taste, and modifying the boiler by anodizing or chrome plating to take care of that "water around the edges" too. Here are photos of the boiler, showing buildup of aluminum oxide, the lip that's fortunately still serviceable on my machine, and the base seal where the lip inserts. The fitting where the boiler attaches is fortunately chrome plated, so its edge hasn't degraded, although it does show build-up of aluminum oxide and possibly scale.





Here's a close-up showing the pitting that can occur in these vintage aluminum boilers. I'd like to find a way to stop that process.



Where the cylinder joins the boiler seems intact, and fortunately it's made of chrome-plated brass:



But I can't seem to find a way to remove it. Here's a view of the bottom:



And I don't know the secret code for removing bolts that appear to be seated in the boiler block itself with no retaining nuts on the other side. That one stumps this newbie, so I look forward to your comments about this:

Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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PacMan (original poster)

#16: Post by PacMan (original poster) »

Your boiler looks very comparable, maybe a little better, to what mine looked like. Let's hope the bottom of your boiler looks better than mine once you pop out the cylinder. To remove the cylinder from the boiler body I followed the OE rebuild guide instructions, detailed in line #4. As suggested in the article I used a hammer handle inserted from the top and knocked out the cylinder. Note that after this step was when my project ended. I hope your cylinder comes out with the boiler section intact!

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drgary
Team HB

#17: Post by drgary »

Thanks for the heads up. That makes me hesitate to knock out the cylinder until I get more advice. The prior owner said he was using the machine until his temporary repair of the heating element contact failed, so in its current state the boiler doesn't leak. More than one expert restorer has issued cautions about disassembling something that could cause more problems than leaving it alone.
Gary
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What I WOULD do for a good cup of coffee!

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PacMan (original poster)

#18: Post by PacMan (original poster) »

I agree. If I had to do it again I wouldn't remove the cylinder. My situation was a little different when I started because water was leaking out of my group when I got the machine. I convinced myself that I should replace all seals, including the one between the cylinder and boiler.

Warrior372

#19: Post by Warrior372 »

Gary,

Those bolts you refer to are most likely threaded on both ends. I ran into some while rebuilding my Prestina, and this must have been something they integrated into the later two piece group Prestina's. Anyway, a local screw store will know exactly what they are. Take those vice pliers, clamp them on as tight as you physically can and then start tapping the handle with a rubber mallet.

You are leading the way for me on this one. I received my Microcimbali a few days ago and am currently completely redoing a Cremina. I should be on the Microcimbali in a week or two. With school starting up again I will not have as much time to dedicate to the machines.

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drgary
Team HB

#20: Post by drgary »

Hey Mike,

Leading the way? I'm hacking my way through the jungle using a pocketknife instead of a machete! At least I had some Papua New Guinea Microlot to power me on. I'll copy your comments over to the Conti thread for continuity there.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!