La Peppina Termomatica

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XS750AU
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#1: Post by XS750AU »

I purchased this La Peppina Termomatica out of Italy. As it turned out there was a mint unit sold out of the USA for not much more than I paid for this one - such is life!





So it was immediately obvious that a new boiler was required. I looked at the glass boilers that where developed but a member here - they looked an interesting challenge. I also considered making one from stainless steel tubing. I finally decided on using a stainless steel cannister, but getting thee precise diameter prooved difficult.
Looking at the original boiler the "socket" that engages the main housing was conical shape that allowed it to be easily pulled down onto the O ring to create the seal. One of the cannisters was a bit larger than the 105mm of the housing. That allowed me to make up some tooling to reform the cannister base to replicate the original boiler taper. The force necessary is supplied by my 20 tonne garage press. There is a 6mm pin that helps align the cannister and tools.




It formed the taper quite easily
Once formed


The base then had 4 large holes drilled through it. With this design the boiler retaining plate is not required as it is integrated into the new form.



It is not as visually appealing as the original glazed boiler, but it should last indefinatley.

The lid was a little problematic, The SS cannister was taller than the original boiler and has a larger diameter. The original lid could not be used. To use the original lever screw system meant that the lid would need to be recessed. I tried using some 0.75mm sheet steel, which was a complete failure. When I pressed the form into it, the outer edge goes into compressionand it crinckled up. I then tried some 3mm thick 5052 Aluminium and it formed up beautifully.



While the boiler is now finished, the portafilter is on it way from Sergio who was the US distributer, and he still has some stock of NOS parts. The parcel has left the US and is due in Sydney today. Looking forward to trying out the new machine.

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truemagellen

#2: Post by truemagellen »

Bravo. I've had so many of these over the years with damaged boilers and this is a stellar fix.

I always had a lid like yours until I bought one new in box someone had stored in their attic. It came with a similar locking lid like yours just with a finished steam wand built in which is useless for steaming. But it also came with a plastic lid with a large hole that was also a handle. That hole was perfect for putting a thermometer into and I never used the locking lid again.

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redbone
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#3: Post by redbone »

Kudos on your ingenuity and fortitude. I like the concept of the La Peppina but remorseful of what it could have been if brass or similar better quality metals were used vs the Zamak (https://en.m.wikipedia.org/wiki/Zamak) FE-AR used. Zamak was prone to Zinc pest (https://en.m.wikipedia.org/wiki/Zinc_pest) as seen inside most La Peppina machines in varying degrees.

If you want colour you can always have the outside powder coated to closer match the original kettle. The Termomatica is the best of the series according to fellow member Nelson crazy4espresso who currently uses one as part of his lever rotation.
Between order and chaos there is espresso.
Semper discens.


Rob
LMWDP #549

XS750AU (original poster)
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#4: Post by XS750AU (original poster) »

The machine has been used, but it appears that it was never maintained. All the screws are original and were pristine (before I pulled it appart). There is no doubt as to why it was put asside, it had a heavy build up of calcium.

I used citric acid to clean the boiler, if there would be any advantage in using vinigar I would be happy to know. Only short soaks, and plenty of physical chipping and scrubbing. I was very nercous about limiting the contact time between the acid and Zamak casting.

The dispersion screen came off without too much effort. The photo is after I replaced the 2 O rings used in the group. I used some "Never Seize" on the screws before replacing them. I could not remove the screw securing the big flapper valve. The valve is still pliable, so if it ain't broke, leave it alone!

Now for the interesting bit. The piston seal was not an O ring

Off to my trusted seal shop. I had very little hope of findiing a similar seal, but they exceeded my expectation. Their belief is that it used a "Quad Ring" which is also known as a X ring. Basically it looks like 4 smaller section O rings molded together.
The original is on the left and the new one on the right.

I am still waiting for the portafilter, but in the free state it pumps water well. Once the handle is pulled down the initial movement up is critical to the result. It really needs an initial surge to close the flapper valve. If you go up very slowly the flapper valve does not always close. If you give it an initial surge then the flapper closes and I consistently get 40ml out.
The boiler is good, but not in perfect condition, and I don't really want to keep using acid on it to clean up the little scale remaiining. Yes it is made of Zamak which does possibly contain some Lead and worse is the possible Cadmium. The data sheet lists both at a maximum 0.3%, the current European Standard requires a maximum of 0.1% in a food application. If I get too worried I might get the boiler water tested.

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drgary
Team HB

#5: Post by drgary »

This is a great fix!

Since you asked, the reason people use vinegar for descaling is it doesn't recrystallize some scale in tiny passages like you get in pressurestats.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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JohnB.
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#6: Post by JohnB. » replying to drgary »

It also works faster & works cold.
LMWDP 267

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drgary
Team HB

#7: Post by drgary »

And for those who enjoy a little salad with their espresso, it tastes good too!
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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XS750AU (original poster)
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#8: Post by XS750AU (original poster) »

drgary wrote:This is a great fix!
Now that I have the forming tool it is easy to make more. If anyone needs a new boiler to get a machine working they can message me.

XS750AU (original poster)
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#9: Post by XS750AU (original poster) »

Help please.
My shipment from Sergio arrived today. I must admit I was somewhat surprised at just how small the portafilter and baskests are. Plus when I lock in the portafilter, it still feels loose, but it does not leak?
Straight after dinner I started playing.
The coffee I am using is a dark roast single origin Ethiopian
In the double filter I started with 14gr and the same grind setting that works for the Expobar and Microcimbali.
The result was uninspiring, very sour and bitter with very little crema.
Changed to 15gr = no better
coarser grind slightly better but underextracted.
I am only getting about 7gr of water per lever stroke - so I am assuming my flapper valve is leaking. There is no water under the machine so I don't believe the piston seal is leaking.
Compared to my Microcimbali and CE14 the La Peppina is proving more difficult to dial in.
If you can point me in the right direction as to dialing a La Peppina it would be greatly appreciated.

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truemagellen

#10: Post by truemagellen »

What technique are you using?.

I would lower the lever, then do a slow pump up and down to about 45 degrees until I felt resistance. Then wait a bit if it is a lighter roast which you don't have. But after resistance a final lowering of lever and let go.

I'll try to find a good video.

Have you place a thermometer in the kettle to determine the temp? Water temp in kettle should be about accurate.