1956 Gaggia Internazionale 1 Group - Page 7

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harrisonpatm

#61: Post by harrisonpatm »

What grease did you use to lube the teeth, and does that mechanism touch water/coffee? Would be handy to know if I come across anything like that in the future. I use FM222 for mixer and grinder gearboxes, it's rated for incidental food contact (though I have no plans to spread it on toast anytime soon), and I would like to know if you use anything better.

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

I use Kynetx - Food Grade Grease, White, NSF H1, NLGI #2 (MD FG26), 14 Oz Cartridge, although it is currently out of stock for the single tube. I've used it on all of my machines to good use so far. It was discovered by the late Old Nuc/Rich.

Anything where the Kynetx grease is used should not normally be in contact with brew water, and for the piston seals and valve seals I use Loxeal-4 or Dow 111
-Ryan
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IamOiman (original poster)
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#63: Post by IamOiman (original poster) »

Just wanted to give an update. I got the needed adjustments for the boiler lid so that it would not interfere with the gasket and boiler flange. To make sure it was sealed properly in the flattened areas a small divot was made in each area then fill with silver solder, and flattened again with abrasives. It fits nicely now, and now the lid is attached to the boiler. The studs used are 55mm M8 x 1.25 A2/304 stainless steel. I found that the holes actually all went to about 27mm after being cleaned out, which is great for ensuring there is a lot of thread engagement.



I added the elements to make sure they fit the brazed brass studs, and cleaned the original element used on the right side afterwards. I get a good measurement with the ohmmeter of about 82Ω, or roughly 176 watts on 120V. This will supplement the 1100W element for a total of 1276 watts, give or take.



Seeing that they fit I then tightened down the elements and boiler nuts except for two on the boiler as I determine where to place the p-stat bracket. It was here I discovered the teflon element gaskets would not seal flat, and I could shine a light through it into the boiler when viewed from the inside. I believe this is due to gasket interference, so I will lightly slice the gaskets a little. If the issue persists I am ok with using a sealant to make sure there are potential leaks, like Loxeal-18 or RTV High temp silicone.


-Ryan
Using a spice grinder violates the Geneva Convention
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IamOiman (original poster)
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#64: Post by IamOiman (original poster) »

This is as far as I can get until the last remaing parts orders come in (Christmas season is brutal for shipping). Flipping the boiler and frame upright, I attached the lead foot in the back. It is a 3/8" BSP thread if you were curious enough, and it is secured by a half nut on top. I put felt feet on the bottom so the lead foot does not damage a wooden surface. I also placed these felts on the front chrome foot and the bottom of the frame. The backsplash is secured by the chrome foot, so I installed both at the same time. It takes a little adjustment to make sure the backsplash lines up with the boiler fittings and the threaded holes for the side bracket pieces. It is easiest done when the foot is free-hanging over a ledge.



The group received a new teflon gasket and new studs. They fit nice and snug, no damaged threads were encountered. It's really cool these parts are still offered commercially.




The last thing I did was cut the new sightglass to replace the odd plastic tube with copper pipe inserts (!?). I am using Fused Quartz glass, 10 mm OD and 1mm thick. When I was doing the research into creating new sight glasses I was concerned with the thinness of the glass wall. I was assuaged by calculating the burst pressure of this material using Barlow's Equation. I'll show the math here. For reference the boiler pressure of most espresso machines will operate no more than 30 psi max (~2 bar). My Internazionale will run around 15 psi/1 bar probably.

P= burst pressure=(2*T*S/D)
S = Fused Quartz Design Tensile Strength: 7000 PSI
T = wall thickness = 0.0394in
D = OD = 0.394in
P = burst pressure = 1400 PSI

So for a working max pressure, P is divided by 4, so 350 PSI should be enough right? :lol: . I did the same calculation for my Classica sight glass, which uses 12.7mm glass 1mm thickness. It was something like 1232 PSI or something crazy high.

To cut the glass I used a little hand tool that cuts a scratch into the glass that allows me to snap the glass into two pieces, one with the desired length. After some measuring I settled on 195mm for a length and made the cut. The litmus test was to see if I could install the glass with all of the sight glass parts. The glass passed the test.




-Ryan
Using a spice grinder violates the Geneva Convention
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IamOiman (original poster)
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#65: Post by IamOiman (original poster) »

I am so close, I just need one type of teflon gasket for the valves. I could use loctite 55 but I really want to see if the gaskets I ordered work; think of it as a sunk cost fallacy at this point :D . In the meanwhile I fabricated the two pipes I will need for the p-stat and vacuum valve. The practice from the Pavoni P67 project really quickened this process, and the 6mm OD pipe is quite easy to bend/adjust for the 1/4" BSP compression fittings. The third larger pipe was for the Urania. The purpose of the blue bucket bath was to wash off the extra flux from each end with citric acid, and after cleaning the pipes were wire wheeled.











I decided to do the boiler testing with all the fittings installed since I have easy access to take off any offending fittings should leaks arise. Loctite 55 was used on each of the four valve threads connecting to the boiler. The sight glass slipped on after with its gaskets along with the manometer. The five valve tap rod glands all received 3/32" teflon packing cord as the seals that I thought would fit were either super snug or super loose. The drip tray also needs two gaskets to seal the thumb screws that secure it to the front chrome foot. The drain pipe connects to a 3/8" BSP pipe which is convenient for me.







The last thing I did was to unite the body panel assembly with the machine to make sure my pipes and p-stat will not interfere with the panels. I will reiterate that the panel assembly is only secured by two M8 bolts and two M5 screws on top, with the side trim pieces simply holding the panel assembly. I can understand the concern about picking up the machine by the panels. I will almost be disappointed when I have to take off the panel assembly for wiring and testing...the pictures do not compare to looking at this machine in person. All surfaces were kept original, although the steam arm is tempting to rechrome I'll admit.






-Ryan
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mikel

#66: Post by mikel »

So cool to see Ryan. As always, thanks for sharing.

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

The valve teflon gaskets finally came in, and they were a perfect fit! With those valves I could finally wire up the machine in preparation for the first test run. I was able to utilize two 25mm holes in the backsplash for the power switch and cable grip. The washer on the grip had an o-ring in between to keep the chrome unmarred.






I filled up the machine for the first time and that is where I found two issues. One heating element and the boiler lid leaked water at room pressure and temp. The heating element on inspection has a warped flange imprint which should be able to be fixed with loxeal 18-10 or related. The boiler flange did not looked affected so my suspicions laid on the lid. On inspection, it was evident the lid has a little different issue as a result from the work on the heating element studs. A portion of the worked on areas do not have a flat flange, as indicated by the light shining from under the relatively straight razor blade. Compare this to an unworked section too. There is a small divot maybe a few thousandths in size that runs along the worked area of the boiler lid for maybe 1/6 of the total circumference. This corroborates what I saw with the leaking water as I saw it leak from two of the bottom boiler hex bolts, where the divot lies. I am pretty certain it should be fine with Loxeal 18-10 or related, but is there anyone out there that can corroborate my statement from their experience? I ask since I don't have any of that Loxeal and want to better justify my purchase of a tube.





I did a small test area of Permatex High Temp red gasket maker but was unsatisfied with the results due to the small surface corrosion that would occur in the curing area. I cleaned it up after.
-Ryan
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drgary
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#68: Post by drgary »

Ryan,

Is it possible that at least the outer groove was used for a string gasket and could be filled with thin o-ring cord?

Also, what if you were to use a layer of soft silicone gasket sheet that would compress and fill the gaps? I use it on one of my machines where I use a thin wire thermocouple inserted through the gasket seal into the boiler. PTFE could also compress to fill that gap. These aren't anything like the original gasket solution, but when built the flanges were probably flat and would accept more conventional material, although I wonder as an amateur if paper gaskets containing asbestos fiber would also compress into uneven gaps.
Gary
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What I WOULD do for a good cup of coffee!

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

It's a possibility for sure. The gap really is tiny. The second sealing ring is not the primary area of leakage, rather the area between the boiler lid holes and the inner groove of the flange surfaces. I think I will obtain a bottle of the loxeal and try that first, then perhaps I will look into a more malleable gasket material as the PTFE did not compress enough at 12-13 Nm of torque, and I am reluctant to exceed the torque too much since some of the boiler holes are original threads.

A solution will be devised, and I will be patient on this one if necessary. I am running out of machines to fix up so I can't be too hasty! :D
-Ryan
Using a spice grinder violates the Geneva Convention
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IamOiman (original poster)
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#70: Post by IamOiman (original poster) »

After some troubleshooting with the boiler lid I finally got it to seal. It needed a little sealant in the divot and the stuff I used did the job (Hylomar Universal Blue). With that issue resolved I could start doing heating cycles to see what needed adjusting. Turning a machine on for the first time is always a little stressful in a way, where the building up for a something that has not been operational in decades makes me feel very excited, especially for something special like this guy. The electrics worked as expected, I got about 1290W between the 110V 1100W new element and original 220V element ran in parallel.

I let the machine reach boiling temperature then turned if off to allow the fittings and bolts to cool so I could tighten them just a bit. For the teflon boiler ring when I initially tightened them they were set to 15Nm. When tightening them after they cooled down from the first heat cycle I measured 12Nm, which is why I need to retighten them back to spec. I turned it back on after to allow it to go to 1.5 bar. There were some significant leaks in the lower sight glass fitting that I had to adjust but eventually I got just about everything buttoned up. The wobbler weight is being used, and I am pleased to see that it will not start releasing pressure until about 1.5 bar which is definitely above the operating pressure I intend to set it to (0.9 bar is my goal).

I ran into an odd issue where when I tried to cock the group, no water would exit. With the Gaggia group this usually means the piston inlet not aligned with the little brass ring that brings water into the group bore after passing the shutoff valve in the back of the group. Either it is too high or too low, but in my case the piston was set too low compared to the brass ring inlet (there is about 1cm of leeway for the water to enter the piston).








To fix this I can adjust the gasket stack. In the original configuration I had some shims inserted that increased the distance the piston needed to travel to reach the inlet brass ring. Removing this ring and inserting it above the inlet brass ring raises the resting position of the piston so it does not need to travel as far when lifting it (the range of motion for the piston is a set distance and cannot easily be altered).

I had to take off the 80mm nut to adjust the gasket stack, and it felt pretty cool to use the OEM tool that probably had not serviced a machine in a while. With the upper group out I also checked if water was even entering inside the group while controlling the shutoff valve. It was also pretty cool to see the valve work when adjusting it. Water definitely was entering inside so I kept progressing on my original solution.






With the gasket stack altered I relubed the piston and inserted the upper group back in the lower group. Since the height of the gasket stack was altered the 80mm nut tightened in a position where the upper group was not facing foward. This is where the allen key grub screws come into play. There is one grub screw on the lower part of the group that secures the 80mm nut, and two more grub screws on the nut itself. The lower single grub screw secures the 80mm nut and the upper two grub screws secure the very top of the group that houses the pinion. Thus locking the lower grub screw allows me to adjust the position of the upper group to the proper orientation. With the grouphead adjusted I turned the machine on again and this time water flowed out!






It was time for the first shot. I used 14g of Saka Crema Bar and placed it in the original size 5 basket that came with the machine. I tamped it with a vintage Gaggia branded tamper to complete the immersion. With the portafilter prepped I pulled the first shot, which of course I filmed for posterity. With this first (really quickly extracted but still tasted good) shot there is just a little adjusting remaining but I can confidently say it is super cool that this guy lives again 8)







-Ryan
Using a spice grinder violates the Geneva Convention
LMWDP #612