Circa 1980's La Marzocco GS2 - Page 4

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
godlyone
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#31: Post by godlyone »

If you are going the new boiler route - consider getting two 1 group boilers - then you can run different temps and it would be pretty neat - new tech in old machine. You can even do a mp or ep style group head

Id recommend just getting newer style where boiler and group is one unit

See my old thread on a linea classic: Restoring a 2 group La Marzocco Linea with Frozen Water Damage!

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IamOiman (original poster)
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#32: Post by IamOiman (original poster) »

I'm dumb enough to try to do it the old way for this guy. The welded groups will be done if I can't easily get a cage boiler
-Ryan
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IamOiman (original poster)
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#33: Post by IamOiman (original poster) »

Ode Solenoid Valves and Stainless panels

I took apart the solenoid valves after realizing I could do so. The are Ode 3 way valves dated from 2004, normally closed model 31A3AV15 that go to each group. They appear to be identical to new ones sold today, but when I attempted to supply 240V power to each one, neither of them actuated and just got warm instead. The actual solenoids may need to be replaced. It also appears the little coils with the spring that have two seals on each end are meant to be replaced as a whole assembly. I did not see a gasket between the stainless stem that threads into the brass block either. I have never worked with solenoid valves so I don't know if it's worth attempting to fix the ones I have or just get new ones.




Here's some more detailed pics of the really scuffed body panels. Even though they appear to be stainless, there is definitely surface rust on all panels. I have been experimenting to see how well I can take out the rust, but I am left with pitting in the material still. I am debating how much to sand down, or if I simply need to leave it so I don't remove too much material.






The cup tray panel had a section 'modded' to fit the modern steam valve. Really unfortunate stuff, but perhaps I can fix it with some help





I also received in the mail some replica Fratelli Bambi stickers for the frame I intend to redo, and some manometer placards if I want the retror look on the manometer. The FB stickers will use the color of the frame (which is the same color brown originally). I am seeing what RAL color most closely matches it (if anyone has a good one let me know!).
-Ryan
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Jeff
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#34: Post by Jeff »

From an old email I sent:

From what I can tell, my "orange" trim panels are RAL 2002. The brownish gray side panels could be RAL 8014 or 8019, hard to tell as they have oxidized with the years.

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Jake_G
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#35: Post by Jake_G »

IamOiman wrote:Even though they appear to be stainless, there is definitely surface rust on all panels. I have been experimenting to see how well I can take out the rust, but I am left with pitting in the material still.
A trick for removing rust from stainless steel is to crumple up a piece of aluminum foil and scrub the stainless steel with vinegar as a "soap". The vinegar and the aluminum create a chemical reaction that attacks rust without really doing much more than gently scuffing the stainless steel. You'll be left with whatever pitting is present, but the rust will disappear.

Cheers!

- Jake
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Peppersass
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#36: Post by Peppersass »

Amazing thread. You have a lot of guts taking on a project like this one.

What fascinates me are a handful of elements that carried forward to the GS/3 line, particularly group design and construction.

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IamOiman (original poster)
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#37: Post by IamOiman (original poster) »

There are more gaskets and parts from modern Marzocco machines that are compatible with the GS2 than I expected.

Cage nuts
The cage nuts used on the groups are a relatively uncommon M7 x 1.0 thread. From reading other restore projects and talking with people, it is highly recommended to clean the threads with a tap so that the bolts can thread on easily and reduce chances of crossthreading and ruining a nut. I used a bottom tap so I engaged as many threads as possible. I used a Ti coated Regal brand tap from circa 1995. There was a surprising amount of crud that came out of every nut, and now I can thread a bolt very smoothly and with little effort.






I have all the frame pieces together and am getting ready to drop them off for powder coating once I settle on a color.
-Ryan
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Filletfellini
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#38: Post by Filletfellini »

Great work. I know a boilermaker in SLC that used to make steam boilers for an equipment manufacturer. PM me if interested and I'll find their contact.

I would just go welded brew boilers, all costs being the same.

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IamOiman (original poster)
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#39: Post by IamOiman (original poster) »

Frame cleanup and chrome estimates

I got all the frame pieces dropped off for powdercoating. I purchased a color wheel for RAL colors, and the closest one was not RAL 8014 or RAL 8018, but rather RAL 8017 (Chocolate Brown). It might look a little off was the color wheel doesn't really show gloss. I peeled off the original Fratelli Bambi sticker beforehand. It will be $800 for 9 frame pieces. I also got my 2nd missing portafilter that was found in a box of random parts that I received a few weeks ago.






I also got a chrome estimate for 19 pieces that include the groups, banjos, steam/hot water wands, feet (which also need repair and is part of the cost), portafilter bodies, and sight glass bits. Before proceeding with the chrome plating, I am waiting to see what type of replacement brew boiler I can get, but the estimate is higher than I expected at 1700 USD :oops: . This is why I prefer preserving machines just due to how expensive plating is around here.
-Ryan
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IamOiman (original poster)
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#40: Post by IamOiman (original poster) »

Replacing the lower sight glass fitting

I have a friend who was kind enough to reproduce the original 1/2" BSP fitting that is normally brazed into the boiler but fell out of mine. I took specific measurements and sent off the original damaged piece to him along with a 1/2" BSP nut to ensure threads were in tolerance. I purchased 4 replicas, and they arrived today. I steeled myself and did the braze job myself using cupalloys 455 silver and HT5 flux (since stainless is involved).






I placed the fitting and painted the flux on. Using a MAP Pro and TS8000 torch, it took almost two minutes of heating up the boiler before solder began melting and securing the joint. After cleaning up the flux in a citric acid bath I realized I could have used less solder, but overall I think when I pressure test it the joint will hold. Fingers crossed!








And since I don't see many demo vids I filmed the brazing too.
-Ryan
Using a spice grinder violates the Geneva Convention
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