Zerowatt CA 708 restoration

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Ehrenrolf
Posts: 5
Joined: 10 months ago

#1: Post by Ehrenrolf »

Hello everyone,
I'm fairly new to the world of coffee but have recently found a disassembled Zerowatt CA 708 (Spain) that apparently my grandfather was working on before his passing about 11 years ago and I'd really like to try to give this machine a new life. I have already ordered a seal kit from Francesco as most of the original seals are in bad condition. Since I have very little experience with restorations I'm a bit cautious about the aluminum stuff, I think I have a rough general idea what needs to be done but would really appreciate some advice if there's anything I need to pay special attention to, if there's things that need to be done in a specific order or whatever else there might need to be done. My first thought was to start with descaling the parts, removing any oxidation and then replacing the seals but I'm guessing some things might pop up as I go (the portafilter probably needs new chrome for example). I couldn't really figure out how to attach images yet but here's a Dropbox Link with some pictures: https://www.dropbox.com/sh/xry0i0van2j1 ... 0UGYa?dl=0
Many thanks for your help in advance!

Nunas
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Joined: 9 years ago

#2: Post by Nunas »

Your grandpa's machine looks clean for its age. Often, aluminum parts on these are all corroded and pitted. Be careful with the descaling; aluminum does not like many chemicals; frankly, if it were mine, I'd not descale the aluminum at all. As far as I know, aluminum oxide is inert and harmless to humans. The amount of scale showing on the stainless parts is small and safe to remove by descaling. There's also some built up coffee residue on some of the stainless bits, which you should be able to get off with a Cafiza soak. If it's really hard, you probably can get it off with isopropyl alcohol; I use that for tough, burnt on oils on my roasters. Have you tested the heater? Apart from the seals, it's about the only thing that can go wrong on these simple lever machines.

Ehrenrolf (original poster)
Posts: 5
Joined: 10 months ago

#3: Post by Ehrenrolf (original poster) »

Thank you for your advice! I will see about the descaling, I think at first I will just try to get the worst stuff off with a tooth brush and see how it looks then. I'll get to work this weekend and probably will post some updates and/or questions then. The heater is definitely working, I'm just a bit worried about possibly having to remove it to replace the seals but I gues I'll just see if that's necessary when the time for that has come. Do you have any opinion on the flaking chrome inside the portafilter? Is that an issue that definitely needs to be addressed before putting it into action?

Nunas
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Posts: 3661
Joined: 9 years ago

#4: Post by Nunas »

The inside of plated portafilters often wears away. That was the case with my 58 mm e61 PFs. However, usually they just erode. If yours is truly flaking, I'd be inclined to try to remove any loose flakes and call it good enough. BTW, here's a resource for parts and info, in case you are not aware http://www.francescoceccarelli.eu/m_zerowatt_eng.htm Francesco can sometimes supply parts that are not on his website.

Ehrenrolf (original poster)
Posts: 5
Joined: 10 months ago

#5: Post by Ehrenrolf (original poster) »

Yes, mine's definitely flaking, I think in the second to last picture you can see the brass showing beneath the chrome, but I think for now I'll follow your advice, thank you again! Maybe I will see if I can get it rechromed after I have everything working. Thanks also for the link, I was aware of Francesco's website, I already have his seal kit in the mail, but it's great to know that he might be able to help with some other parts as well.

Ehrenrolf (original poster)
Posts: 5
Joined: 10 months ago

#6: Post by Ehrenrolf (original poster) »

I have started working on the CA 708 and since I found it disassembled, I tried figuring out how to reassamble after a very rough first cleaning. So far most parts seem straight forward but I'm not sure how the group shower screen is attached. Unlike the Italian version, the Spanish one doesn't seem to have a spring to hold it in place, is it simply pressed against the gasket by the portafilter?

Nunas
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Posts: 3661
Joined: 9 years ago

#7: Post by Nunas »

Sorry, I don't know. You might ask Francesco.

Ehrenrolf (original poster)
Posts: 5
Joined: 10 months ago

#8: Post by Ehrenrolf (original poster) »

Thanks for your answer! Francesco to the rescue again it is then