Hello,

I've been reading HB for months now and I finally have a reason to post; I've acquired a La Pavoni of my own. Shortly after finding these forums, I was drawn to the Lever section and I quickly fell in love with the look and simplicity of these machines. I was ready to purchase a new one when I learned they're still made, but then I fell into the threads of restorations and the virtues of these older machines compared to their modern counterparts. No stranger to working on old things (cars, bicycles, etc.), I felt I was up to the task of restoring one of these machines. I kept an eye on eBay and spent a few hours searching Craigslist until I came across the machine below. The seller believed it was a 1975, but according to my research using Francesco's website I think it is 1970-1973. Sadly the final digit of the date is worn off as you can see below and there is no serial number plate on the machine.

Appearance wise, it does look great and it won't take much to polish up. I do have a question related to the scale. It is green inside, like a penny would be after oxidation, while most pictures I have seen of scale in these has been white. Is there any special precaution I need to take in removing this? Is this possibly because the inner chrome plating is gone and the raw brass is oxidizing? The heating element does work so I believe the recommended technique is 5% white vinegar mixture and heat the solution in the boiler?

Other parts needed/planned (open to suggestions):
OE Pre-Millenium gasket kit
OE stainless C-clips
Espresso Care gauge
Espresso Care gauge adapter
Espresso Care stainless upper tray
Update wiring/plug (similar to what drgary is doing, thank you for the excellent thread!)
3-way switch (inspiration is the Carling that pizzigri used)
Portafilter (Will the ROK work on this generation of pre-millenium?)
Elektra double basket

Here are some pictures of the machine:






Heating element is intact and functions, some rust it seems.




Brass sleeve with the removable shower screen leads me to believe it is 1970-1973?


Underside. Oxidation on heating element terminals.


Manufacturing date. White text is my best guess at faded lettering.


Only number markings on the machine.

Thank you all for looking and any advice you have!

The underside shot suggests OP is right in dating this as 1970--1973: the switch and wiring are indicative of a Massimo/Minimo model.

Blue or green scale described in this post is due to the scale containing substantial amounts of copper ion. I suspect that this is the result of the former owner using bad water that contained chloride ion. It is clear that those who continue to use water that produces blue or green scale they are risking very serious damage to the machine. If one get blue liquid from descaling this, of course, is also true. Some espresso machine manufacturers will not honour any guarantees from damage caused by using contaminated water. The electrode potentials for copper are such that it cannot react with pure water. Copper oxidation in pure water is reaction with OXYGEN. Chloride GREATLY facilitates the reaction with oxygen. (Normally copper gets a thin layer of CuO and/or Cu₂O that protects from further oxidation. Descaling tends to remove this, and a new layer forms. The layer is most stable in neutral to slightly basic water.) Because these old machines are irreplaceable, it is important to do everything to keep them intact. Occasionally used machines are found with CaSO₄ scale. This will not dissolve in citric acid or acetic acid solutions. My 1978 was that way. The only way that makes sense to me to get rid of that scale is to use very pure water, distilled or deionised, for several weeks, avoiding coffees that are acidic during this period to prevent having sour espresso. During that time you will have quite hard water from the dissolution of the calcium sulphate. Eventually the CaSO₄ will be gone without dissolving the boiler!

Probably the LEAST corrosive water to use is pure distilled or high quality reverse osmosis water with about 1.0 mM sodium or potassium bicarbonate and a trace of sodium or potassium phosphate. This results in weakly alkaline water that protects the metal surface, and also has the right pH to make espresso. There is far more Ca and Mg in the beans than in the hardest water, so the Ca and Mg composition of the espresso will be more or less like from hard water anyway. This also results in clean espresso without water pollutants in it, and one can adjust it for different coffees and roasts.

[Edit] The formula weight of NaHCO₃ is 84g/mole. For KHCO₃ it is 100g/mole. Thus one needs about 84 mg of NaHCO₃ or about 100 mg of KHCO₃ to produce a 1.0 mM solution. I have a 10% w/v solution of KHCO₃ that I use for this purpose. 1.0 mL of this has 0.1 grams, or 100 mg. I add this to 1.0 litre water.

I have a 1964 model Europiccola. It has the sight gauge that does not have a removable cap on top, and it has the dispersion screen that is difficult to remove. It apparently had been in storage since shortly after it was made. It looks essentially new. Many regard these old machines as the best La Pavoni ever made. I think that right! They are even better once you realise the principle of their operation!

There are TWO different types of portafilters (maybe more?) on the 1974-2000 group equipped machines.
The EARLY one is most desirable. It has M10 threads on the handle stud and is made of a different copper alloy than later ones which have M12 threads on the handle stud. The ones with M10 seem to be slightly deeper and hold the Elektra 49mm basket easily, at least in the case of the one I have. If you have an unplated one of the M10 threaded variety, it will look like copper because of the high copper content of the alloy used.

The 1961-1974 portafilters are also deep, and give the appearance of higher quality.

It will be very difficult to find a portafilter made for the 1961-1973 groups, but all 49mm portafilters seem to be interchangeable, I have a 1964, 1978, and 1999, and any of the portafilters will fit on any of the machines. Again, remember, that that portafilter threads to lock onto groups are chiral (handed.) La Pavoni uses left handed threads. This tends to make them incompatible with 49mm portafilters from non La Pavoni machines.

drgary wrote:Adam,

Congratulations on your acquisition. And you're welcome. I'm enjoying writing that thread. Your machine is not pre-Millennium, though. It is first-generation. The machines we know as the group preceding the Millennium model, or "pre-Millennium" are second generation. Make sure you get the right gaskets from OE.

To truly know the age of your machine it would help if you could post photos from the other side, showing the switch. If the switch is other than Massimo/Minimo you can turn it off. Otherwise when it's plugged in it is on. If it's a High/Off/Low switch and it works, might as well keep it.

Thank you for the response and the links, Gary. I'm excited to work on this and more excited to make espresso with it! I was staring at those gasket kits last night wondering if I needed the sleeve edition kit, even though I have the removable shower screen. I believe I'll buy the sleeve removal tool as well then. I did plan to buy that teflon pressure relief valve after I saw it posted in your thread.


Here's an image of the switch. It is the massimo/minimo two position one.

rpavlis wrote:Blue or green scale described in this post is due to the scale containing substantial amounts of copper ion...If one get blue liquid from descaling this, of course, is also true...(Normally copper gets a thin layer of CuO and/or Cu₂O that protects from further oxidation. Descaling tends to remove this, and a new layer forms. The layer is most stable in neutral to slightly basic water.)...This will not dissolve in citric acid or acetic acid solutions...The only way that makes sense to me to get rid of that scale is to use very pure water, distilled or deionised, for several weeks, avoiding coffees that are acidic during this period to prevent having sour espresso. During that time you will have quite hard water from the dissolution of the calcium sulphate. Eventually the CaSO₄ will be gone without dissolving the boiler!

Thank you for all of the insight into the scale, Robert. If I'm understanding your post correctly (and it's been a long time since I thought about chemistry), I simply run distilled water through the machine for a few weeks to descale it (due to alkalinity of scale the vinegar won't work)? This scale is "harmless" to ingest when dissolved in the water?

rpavlis wrote:There are TWO different types of portafilters (maybe more?) on the 1974-2000 group equipped machines.

It will be very difficult to find a portafilter made for the 1961-1973 groups, but all 49mm portafilters seem to be interchangeable, I have a 1964, 1978, and 1999, and any of the portafilters will fit on any of the machines. Again, remember, that that portafilter threads to lock onto groups are chiral (handed.) La Pavoni uses left handed threads. This tends to make them incompatible with 49mm portafilters from non La Pavoni machines.

That's what I was afraid of and what I was running into with my research. Sadly, all I have with this machine is what is pictured and the shower screen (which luckily cleaned up very nicely). If I was going to be shaving/hacking up a portafilter to work with it, I felt more comfortable doing so with the $30 ROK than one of the true pre-millenium's that Stefano sells. The ROK is left handed and it apparently does work with some filing according to another thread.

What you should do is try to descale it first with the white vinegar solution (acetic acid) or citric acid solution. If the scale dissolve, that means that the scale was CaCO₃ or CaCO₃ with MgCO₃. You are then in luck, and you will not have to do any thing else.

Sulphate scale will NOT dissolve in either acetic acid or citric acid solutions because the second ionisation of sulphate is too strong, and these weak acids are not enough to protonate sulphate and bring it into solution. Strong acids would do it, but they will also remove zinc from the brass! About 2 or so grams of CaSO₄ will dissolve per litre of water, so simply using pure water will gradually remove sulphate scale without using nasty things.

Got it, thank you Robert! I will try the white vinegar solution this morning and see if there is any change.