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Thread: Boema 2 group lever

  1. #1
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    Boema 2 group lever

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Looks like I'll be picking this up this afternoon. The text with the add read "Rather stylish vintage 2 group vintage lever pull coffee machine. Was working in family cafe, then in storage for years. Plugged it in this morning, boiler is working fine, leak coming from the left hand group head. Will need gaskets."

    I'll likely repair (not restore), play with it for a while (I've never had a lever before), and then decide whether I want it in my life long term. I'd be interested to know whether there is a strong market for these in running order should I decide to move it on and what I might get ... I need to set a repair budget!

    If anyone has any information about it (model, era, boiler details etc) I'd be grateful.
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  2. #2
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    Hi , looks like a fun project. If it's been sitting for years, groups will most likely need a full rebuild, not just seals. The groups are based on Astoria/CMA lever group, but even that has changed a few times over the years, so check you're getting parts for the earlier version . Boema the company is still going, and from what i've heard they are very helpful with parts if available for these old machines.

    As for re-sale - it's a tough one, it's way too big for most people at home, but cafes don't want them either . I always try and get single groups if possible.You may be lucky and get someone with a coffee cart or similar who wants it, but then it would need gas install and full rebuild...

    https://coffeesnobs.com.au/brewing-e...d-madness.html
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  3. #3
    Senior Member LeroyC's Avatar
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    Rick Bond ‘The Coffee Machinist’ is the man to talk to about this one. He has a certain affection for old Boema levers. Boema themselves are good to deal with but I can tell you now they won’t have parts for this other than maybe gaskets and o rings.
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  4. #4
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    I'm in trouble ... broken rusty bolts /studs between group and boiler.

    There is a part (I don't know what to call it) between the boiler and the lever group. It seems connected to the boiler by a huge nut (about 43mm if I recall), and to the group by 2 bolts (top) and 2 studs (bottom).

    What happens if I undo the huge nuts between the boiler and this part attached to the group ... will that separate it from the boiler at least .... I'm hoping there will be enough room to jenga it free from the face plate, and can I at least then take the group to a machine shop to drill the bolts out. You cannot get at them from either side until the boiler and group are separated.

  5. #5
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    I got 1 out of 8 bolts / studs out between the group and boiler flange ... the rest were corroded in and got drilled out to be replaced with M10 stainless hardware. I managed to remove the boiler flange (I don't know what to call it) from the boiler via the compression fittings. They were very tight, but a bit of tap tap on the shifter on the big nuts got them loose and I was able to separate the boiler and groups which then provided access to the flange faces to drill out the corroded fasteners. I was very thankful, as they would have been the end of the project.

    Does anyone know if these old Boema lever groups are sleeved? I read that they are based on CMA/Astoria groups (which are sleeved) but I don't think my groups are ... if they are its very difficult to spot. I have 'pushed' carefully (but with some force) on the shower screen end of what would be the inner sleeve and it didn't budge. Unless I can be convinced, I'm going to clean up the group as is.

    There appears to be very little information around specifically about Boema lever machines.

    Now to tackle the boiler and valves ... I hope the worst of it is behind me, but I fear not. I'm not game to order anything for the rebuild until I can get it all apart without breaking anything I cannot replace.
    Last edited by towe0609; 15th January 2019 at 03:25 PM.
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  6. #6
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    Good luck mate. I have done a number of commercial machine rebuilds and the constant fear of seized and broken bolts is pretty much the entire battle. It sounds like you are doing well - just the boiler bolts to tackle yet and then it should be plain sailing.
    Once the bolts are out of the way I find the rest of the rebuild - the cleaning, polishing and reassembling - to be very relaxing and enjoyable.
    Post a few pictures - of anything - seized bolts, disassembled groups, a rusty frame. There are a lot of people on this board who really enjoy the vicarious rebuild.
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  7. #7
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    I've got the boiler apart ... I had to drill 2 of the 10 bolts. The boiler and water level float have been soaked in Hydrochloric acid which worked a treat and look pretty good. Less damage to the steel ring than on the one the Coffee Machinist restored. The float has come up like new, and I was even able to flip the little rubber seat for the valve and its like new!

    I've had some other priorities recently (I had an intermittent starter motor on my car which I decided to tackle repairing myself) ... so not much progress ... but my next challenge (other than more cleaning of parts) is to source a sheet of teflon and make a new gasket for the boiler. Any advice about that would be appreciated. I'm not sure how thick it should be ... I was thinking maybe 2.0 or 2.5mm? Any idea where to source? Best way to cut?

    I'll try to get some photos up soon.

  8. #8
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    I have just sourced some PTFE for a project of my own and had some trouble tracking it down. Firstly its quite expensive so anyone selling it by the full sheet wants a few hundred dollars which is way more than I need. I managed to buy a 300 x 300mm x 2mm thick sheet for $20 or so on ebay which seems a lot, but not when you discover that a single 25mm seal is $5 from a spare parts place, then it seems quite economical. I plan to have a friend laser cut me a bunch of small washers for various valves and fittings on my current rebuild project. I can't imagine having to cut the stuff by hand as its pretty tough, but a larger gasket like for a boiler should be more manageable. you'll probably want a punch for the bolt holes.
    Also Hydrochloric acid is a bit harsh for cleaning and descaling as it readily reacts with the copper of the boiler. its probably worth picking up either citric acid or a commercial descaler such as Vanish from Coffeeparts.
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  9. #9
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    I usually use Klingersil 4330 , again it is expensive in small quantities though. I have a large roll of it now . It's cut-able with hole punches and i usually use a gasket circle cutter, mounted in a drill. Send me a PM if you'd like a piece cut off and sent
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  10. #10
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    Quote Originally Posted by kofekitt View Post
    I usually use Klingersil 4330 , again it is expensive in small quantities though. I have a large roll of it now . It's cut-able with hole punches and i usually use a gasket circle cutter, mounted in a drill. Send me a PM if you'd like a piece cut off and sent
    Can I check ... do you mean Klingersil 4430 - 4330 seems to be some sort of packing material rather than gasket sheet.

    Klingersil 4430 looks pretty suitable to the job based on my very novice assessment of the tech sheet. What thickness do you have?

    I'll measure up the boiler and send you a PM with details and we can go from there. I appreciate the advice.

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    Whoops, yes it's 4430, 2.0mm thick from memory, but would have to check tomorrow

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    A few photos to keep it interesting ...

    Kofekitt - I'd need a sheet min 23 and pref 26 or more cm's square. I'll PM you so you can let me know a price. I assume I could use it to make group flange gaskets too ... so might get a bit more if you have more than you need.
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  13. #13
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    Refurbished all the valves, de-scaled and cleaned groups, and generally got bits and pieces ready to rebuild. Waiting for gasket cutter to arrive from Japan and for some stainless hardware ... but I'm feeling more confident its all going to go back together. A few progress photos for interest.
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  14. #14
    Senior Member Lyrebird's Avatar
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    Quote Originally Posted by towe0609 View Post
    Waiting for gasket cutter to arrive from Japan
    Got a link?

  15. #15
    Senior Member JMcCee's Avatar
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    What's a gasket cutter from Japan look like and why do u need it?

  16. #16
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    You don't have to need something as cool as a custom gasket cutter.
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  17. #17
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    Quote Originally Posted by JMcCee View Post
    What's a gasket cutter from Japan look like and why do u need it?
    Olfa cutter : #90B Heavy-Duty Compass Circle Cutter

    Because I didn't know how else to cut a perfect circle in Klingersil 4430 ... not even sure this will do the trick ... but I hope so.

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    Things starting to get a bit more serious now ... re-assembly commenced ... but still waiting for tools and parts to be able to make real progress.

    Interesting to look back at where I started (see fourth photo in this post).

    If anyone can point me in the direction of some rubber seals (see picture for example) for the boiler level sight glass (9mm ID) I"d be grateful. The seals were toast and I doubt the dodgy o-ring configuration I came up with will seal. From what I can gather the CMA/Astoria set up is for 11mm glass tube so unfortunately the commonly available gaskets are no good.
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    Last edited by towe0609; 25th March 2019 at 12:29 PM. Reason: Big difference between ID and OD!

  19. #19
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    The sight glass seals for the little home pavoni levers are 15 x 9 x 5mm silicon. Could that work?
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  20. #20
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    Quote Originally Posted by kofekitt View Post
    The sight glass seals for the little home pavoni levers are 15 x 9 x 5mm silicon. Could that work?
    They look like they could be just the ticket ... thanks again Mike.

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    Not quite sure how to interpret the results of this test ... but I look forward to the day I can replicate it!

    https://www.youtube.com/watch?v=tJDc9BLl_5M
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  22. #22
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    Silicone seals arrived and installed.

    I’ve discovered that one lever only operates in full range of motion with brass (seal section) unscrewed a few turns from the pistons ‘arm’. Ie the spring is slightly less compressed. Is there a ‘set up’ procedure for the pistons?
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  23. #23
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    Hi again, did you use the 130mm or 140mm springs?

  24. #24
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    New stainless 130mm springs (700735-x)

  25. #25
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    Maybe put a spacer on the shaft so piston doesn't screw on as far. As long as piston isn't sticking out of the bore, it's fine. Bottom of piston should be approx flush with bottom of bore, have a pic?

  26. #26
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    Quote Originally Posted by kofekitt View Post
    Bottom of piston should be approx flush with bottom of bore, have a pic?
    Thanks ... I'll 'pack' the space with a washer ... but I doubt the piston will turn on the shaft anyway with the big spring holding it firmly in place.

    I've already installed the shower screens, and at $20 a pop I don't want to risk damaging it trying to remove ... so no ability to check how flush with bottom of bore unfortunately. Might have to cross my fingers on that one.

    I should have studied it more closely, but when the bore is up (ie. spring compressed) fully, I assume it is above the water inlet point to the chamber. But what are the small holes in the base of the piston for? Are they just to slow the pace of water pushing against the seals when the piston is released? Or do they have some function associated with the inlet?

  27. #27
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    The holes in the piston are to allow water flow through and too 'energise' the seals (make the seal edge flare out and work better)

    Are the shower screens the toothed variety? If you push in the middle (with the piston raised), they pop into a concave shape and are easy to remove. Same for installing - pop them into concave shape, hold in position, and poke a wooden dowel down the bore to pop back into convex shape

  28. #28
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    Cut a boiler gasket using the new gasket cutter which worked well. Waiting for stainless fasteners, but put it together with mild steel bolts as a test run ... lookin' good!

    Any reason not to mount the new pressurestat directly to the boiler? Previously it was mounted to the frame via copper pipe with compression fittings etc ... but I selected a pressurestat with the right sized fitting so fitting directly to the boiler was an option. I can also make up a pipe to mount it away from the boiler if there is a reason to do so.
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  29. #29
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    Best to keep the p/stat mounted away from the boiler so as to avoid accelerated degradation of the electrical and plastic components of the device...

    Mal.
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  30. #30
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    Quote Originally Posted by Dimal View Post
    Best to keep the p/stat mounted away from the boiler so as to avoid accelerated degradation of the electrical and plastic components of the device...

    Mal.
    OK ... thanks.
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  31. #31
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    Well, I'm up and running. The pipe bender I bought was rubbish for bending 3/8 copper ... so other than one new pipe, I've just re-installed the old (hard) pipe, and still have a couple of minor leaks from compression fittings which I think would be easily sorted by annealing the copper pipe ... but there is espresso to make ... so that can wait. I'm considering just lashing out and buying a dedicated 3/8 bender ... which might then allow me to make some new stainless steam arms too.

    My inlet tap has a drip ... waiting for the viton o-ring kit to arrive before I tackle that. Nothing the occasional wipe with a cloth doesn't fix.

    All the main things ... boiler gasket, element gasket, water inlet gasket, group flange gaskets are great. Not a drip.

    Unfortunately the old float valve controlling water inlet hasn't worked, and I'm not pulling the boiler apart to find out why for now ..... so am controlling water level in boiler manually ... which I find is actually no big deal ... I only need to do it once a day at most.

    The groups/levers are working beautifully. Pulling shots without the noise of a pump really is nice.

    I've set the pressurestat at 1.2bar and can walk up and pull a shot without any 'flush'.

    I've used the old toothpick trick to block some of the 5 holes in the steam tip to make steaming small milk volumes easier ... and am now getting good textured milk too.

    Initial impressions are it is very forgiving ... shot consistency is high, with the exception of when the dose in the basket is too small.

    I now need to turn my mind back to roasting so I've got some fresh beans to work with (its been ALDI beans to date), and see what this baby can really do.

    Shout out to kofekitt for his assistance with the gasket material and other advice.
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    Last edited by towe0609; 5th May 2019 at 10:04 PM.
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  32. #32
    Mal Dimal's Avatar
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    Great outcome "towe0609", well done mate...

    Mal.



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