Maybe my fear of plastic boiler caps having catastrophic failure was well founded. Not too long after I got my 1999 La Pavoni I discarded its worthless plastic cap and went to my shop and made a brass replacement. It is fairly easy to do with a small lathe and an M32x2.0 die. However, there is a learning curve. Instead of putting the die in an enormous die stock, I mounted it on a 4 jaw lathe chuck! I put a cylindrical piece of ebony on it for the handle, because I thought that would make the cap easier to handle. (That has been the case for me.)

Decided to post here to avoid multiple threads on same subject.

Brand new Pavoni Pro, purchased around mid April this year. I was away from home for too long, not being able to put into use since July. So, everything was kept in original box dissembled since I would not be able to use it. Back to home, assembled again. Used it for 2 days back to back. On to third day, ready to fill the boiler, took a hold on the cap and boom! Wood cap in my hand, the base on boiler. Yeah, I know nothing epoxy can't fix but disappointing. Also proof rpavlis was right about Pavoni going cheap. Speaking of cheap, my 8 year old well used Epoca portafilter still keeping its plating, whereas I see the brass in Pavoni portafilter. Once again, disappointing.

Pavoni



Epoca

I concur with drgary, don't use it until it is properly fixed, And I would not personally want epoxy either...I am shocked it is plastic. I would send it back if it was me, and have an attorney contact them if they gave me an issue. Somehow they need to learn that critical safety components are not acceptable areas to cheap out...

It is truly ridiculous that La Pavoni makes these caps from polymers at all. I always thought that they had the potential for long term catastrophic failure. Even more ridiculous is the price that they ask for replacements, whether wooden and junk plastic or all junk plastic. The quality downturn to plastic occurred in the late 1980s, if I remember correctly.

As I have posted previously, it is possible to make replacement brass caps and attach some sort of insulating material to them. The threads are M32x2.0. Dies that size can be obtained for much less than the OEM caps!

Thanks for all your input.

In regards to making a replacement cap, while I excel at using an electric screwdriver (ie. last time it took me only 5 days to dissemble a shower screen ) my skills with shaping tools are very limited. As a side note, the conclusion I came to after years of reading various hobbyist forums, along with their social security number, every American citizen born with either a wooden or a metal lathe installed at their basement or garage so they are able to turn salad bowls, tampers, smoking pipes or gicleurs on demand if a sudden need for one of these items arise. Well, our basement mainly used for storing empty cardboard boxes and old mattresses. Therefore, in my case I will have to write to the importer, which I acquired my Pavoni Pro from and ask them to resolve this on my behalf. However, I am skeptical they will be able to resolve it through the manufacturer. Italian manufacturers tend to respond with all caps (no pun) and lots of "never heard of, never happened before, never ever and ever never".. So I am already in search of a type of resin or something else to fix the cap. For now I screw the plastic cap with a wrench when the machine is cold, wait for it to come to pressure and check if there is any type of leaking. If everything looks alright then I take 2 or 3 shots, turn off, wait until it is completely cold until next day to unscrew & repeat the process. Yes, I am perfectly aware of the risk I am taking. If the importer can not offer a resolution, the other alternative would be searching for a brass cap which is readily made or finding somebody in my country to do it for me.

All that is said, I believe as consumers we shouldn't have been forced to do modifications on such expensive and brand new products unless of course that is what our aim is/was. The inconvenience caused by a simple cap here takes all the joy of modifying for better performance or usage. Now I have to do this modification so that my machine can operate properly and conveniently!

I have an 2009 machine with the all-plastic cap. Like kahvedelisi, I have no machine shop to fab a metal replacement, and paying to have one made is an unlikely option for me. When Robert says mine is junk I have to pay attention. But I am confused about the failures mentioned in this thread. Are any of them caused by the plastic threads shearing off when the cap was firmly in place (which of course is my concern)? On my boiler there are 4 threads, and also 4 threads that engage on the cap. My cap is always loose and under no stress (with my funnel covering it as a reminder) when the machine is not in use and as soon as the handle rises up - usually about 15 minutes after use. My cap threads look perfect visually at age 6 yrs for whatever that is worth. I am careful to take very good care of my machine.

I'd be very interested to know:
A) what is the psi force working against those threads in a boiler operating at .75 to .85 bar, given the diameter of the cap and the number of threads over which that force is distributed.
B) what is the test failure force required to shear all 4 threads on a cap in good condition relative to A).
C) (and of course, would a cap that looks perfect and is used properly one day just give out from age, or heat cycling?)

Back several decades ago I owned a paint pump producing 3,000 psi so certainly have a healthy respect for pressure.

regards,
Rich

It always has seemed ridiculous that the manufacturer of these machines often dramatically reduces that quality of these machines by introducing junk quality parts. The plastic fill cap, is, unfortunately just one of several.

0. The junk plastic fill cap discussed in this thread.

1. The well made group handle was degraded in the 1970s.

2. A flimsy sheet metal, usually steel, base appeared around 1980 to replace a much heavier duty part. From time to time a few machines, however, have been made with a decent metal for this purpose, brass. The steel ones are notorious for rusting.

3. The brass piston was replaced with polyphenylenesulphide in about 1997. This piece of junk part was eventually discontinued and replaced with the original.

4. The group piston sleeve design of generation I machines (1961 to 1973) was reinducted in generation III in 2001. Of course the new sleeve is trash plastic! To make matters even worse the dip tube is now fastened to a piece of junk plastic!

5. The retaining ring that holds the boiler in the base was changed from brass to plastic in the late 1990s. After several years this junk was eventually restored to a decent part, I think about 2007.

6. At some point the steam knob began to be attached with a roll pin, making the steam knob difficult to remove without breaking it. (Of all trash parts,this is perhaps the easiest to remedy. One can simply run an M4 tap through the hole for the roll pin and then use a stainless grub (set) screw instead.)

7. The portafilter handles are presently held in place with ordinary steel threaded rod that can (and does) corrode. When corrosion is not caught in time substantial skill is required to remove the rusted mess. (Solution: replace with stainless or brass.)

8. Sometimes the company has taken chrome plated models and plated them to look like real brass ones. There are LOTS of fake brass models out there that the company itself produced and sold.

The company HAS introduced some great improvements like the instantly removable steam wand. They introduced a vacuum relief system, but the way it was implemented was also questionable engineering.

It would surprise me if the company saved even €10 in all of these degrading modifications. They lose a lot more all the time from loss of sales!

Perhaps others can list more degrading modifications that have been introduced in the over 50 years these machines have been in production.

The real concern here is that in time polymer parts can fail. Should some of these parts fail while the machine with them is still in service, the result could be very bad. Even polymeric materials that are initially wonderful can have serious problems in time, especially when they are subject to frequent high loads and thermal cyclicing.

JB Weld is rated for 500F continuous so it may be used to reattach the plastic threaded portion to the wood top. Do not use anything else except the slow cure JB Weld as the majority are polyester or low grade epoxy that will fail at 250F+.

There are several different organic compounds used to make epoxy resins. (Most common are probably bis phenol A and hydroquinone). There are also several different chemical reactions used to "cure" them. The resins are reacted with another material commonly referred to as the "hardener." The mercaptan based curing materials are very rapid. Many amine based materials produce especially good materials. They tend to require many hours to cure at room temperature. Organic polyacid cure systems generally require heating to cure at all.

I would recommend against the use of the mercaptan fast cure system and also the polyacid one. Usually places that sell these things provide information about cure rates, and you can usually learn from Internet sources what type of system it is. These resins can be very very durable because they are thermoset materials with cross links. Your boiler temperature will commonly be in the 115 to 120 degree range, and you want something with an higher thermal stability range than that. I think the right epoxy resin is the best choice here.

Thanks a lot. I am already in search, looking for what is available here. I have a tendency to read every single word written on product labels, unfortunately Turkish web sites do not provide much information. So I will have to go to some of these places and search in person.

I assume whatever Pavoni used for attaching too pieces was not durable to heat and from the remaining amount I see inside the cap, they gone cheap with that as well It is near ghost to non! The inner part looks slightly glossy, nothing else there. Tomorrow I will take detailed pictures in daylight.

Once again, thanks for all your input, very appreciated.