It's alive
Congrats!!!

so do those just brew at 1 bar? Congrats btw, and also fair enough on the lead question, i guess it is what it is.

Paul_Pratt wrote:I sealed up the boiler today, put the lid on and the safety valve. Then turned her on. As it started to build pressure there were of course new leaks, the sight glass had to be redone. Luckily you can just close off the top and bottom fittings and I was able to work on the glass whilst it heated up. I added some more packing and now it is leak free.

If I was going to use this machine I believe it needs at least 2.5kw heating elements. I knew it would be under powered with only 1.5kw but it still came up to pressure, albeit quite slowly. Good enough for me to have a play.

So here you go, 1st test shot.

video

The machine was on all day and the pressure switch turns off at 1.1bar. I was so thankful to hear it click off as it would be a real pain to adjust on the table it is on now. The groups function properly, but sometimes I can see a little leak from the group. I knew these would be hard to get leak free, I have had many many hours on a different machine with a similar set-up.

I will continue playing this week, I hope I can finish up the pressure gauge too. I also need to research about the group technique. The lever positions are Off - Steam - Brew. I wonder if I am meant to dwell on steam as a sort of pre infusion. What is interesting is after the shot the drain definitely gets some use, there is a definite woosh as you put the lever back to the rest position.

sluflyer06 wrote:so do those just brew at 1 bar? Congrats btw, and also fair enough on the lead question, i guess it is what it is.

Yes it brews at around 1 bar, so just a moka pot really. It would be another 20 years before espresso became espresso with crema.

I did a bit of reading today and looked over the instructions from a catalogue (from Sebastien).

• It says 6-7g coffee - I used 14g yesterday as it looked to be a double basket

• The lever should go from closed position to brewing water position, after 1/3 a cup of coffee you then move to steam position to complete filling the cup

• It says the time for brewing the coffee is 3/4 of 1 minute

Sounds like another video is on order!

Paul_Pratt wrote:Yes it brews at around 1 bar, so just a moka pot really. It would be another 20 years before espresso became espresso with crema.

Yes, but in its day it brewed "cafee' espresso!" I think 1.5 to 2 bar was the most brew pressure these early Bezzera/Pavoni machines could muster, but at 45 seconds per extraction they were considered lightning fast. I think you could get yours up to 2 bar if you really wanted to, but I think it's fine just where it is. What a pleasure to see it making coffee after nearly a century!

She is purring like a kitten now She was on all day and the brewing groups were leak free and functioning well.

With regards the boiler pressure, the instruction manual says 0.8 bar (well they say 0.8 atm) minimum and 1.0 atm maximum. The boiler is stamped with a 2.0 kg rating and you always allow some extra, so I don't believe they are meant to operate around 1.0 bar. And yes I have no idea why they use kg, bar and atm and not just stick to one unit.

Here is the boiler "certificate", as you can see the date matches the boiler stamp of 01/05/29



Here is the boiler lid and the bottom of the safety valve. The plating is original, it cleaned up very well.



The safety valve is working well. It starts to hiss around 0.8 bar. I have only cleaned it up and not done anything to the 2 mating surfaces. At the moment you have 2 brass surfaces forming a seal, I could try re-lapping them to get it leak free but for now it is working well.

Another amazing restoration Paul. I'm jealous of your silver soldering and machining skills. And your ability to find these gems, or do they find you?

The Plezon also used a mica heating element, and it was from the 60's.

The machine has been on almost all week now and so far so good. I have tried many coffees and have really dialed back the grind setting. I think it still needs a coarser grind but it is getting there. I also tried an Italian pre ground brick (Kimbo) and it was actually a gusher. So I need to find somewhere inbetween the 2.

Here is my latest effort:
The coffee it is making so far is like a V60 brew but with more body. It is actually not as bad as it looks. I have an old Faema lever set up in the other side of the office and I did a quick comparison between my morning americano on the Faema and a coffee from the Pavoni and the taste is quite close, but the Pavoni has more body and seems a tiny bit muddier.

I will tidy up the office next week and for sure the Pavoni will now be plumbed in for a while in the kitchen area.

I did a little bit of work on the pressure gauge, it is actually missing so I am trying to replicate one. It is a bottom connection style gauge and I managed to find a Wika gauge as a donor, it has the same range 0-4kg. So the original is like this:



And here is my Wika donor



I can get the correct dimensions from my Faema Venere that I use daily in the office. Here it is with the cover removed



So today I did the bulk of the work making the back section, the aluminium ring that goes between the glass and the dial, and I cut out some aluminium blanks for making the dials. Here is the back section and the aluminium ring. The back section is roughed out for now, I need to mill some material out from the walls, next week I will do that.



I had commissioned someone to make the dial artwork, I will screen print the dials, there is a place not far from my office who can do it.



And here are some dial blanks that I cut from aluminium on my CNC machine. There is still a lot to do but I am slowly getting there. I will also mull over next week how I will make the hand. The original on the Pavoni is just so awesome I just have to have a go at replicating it.