Londinium L1 pre-infusion channeling - Page 2

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irvingggg (original poster)
Posts: 7
Joined: 3 years ago

#11: Post by irvingggg (original poster) »

Then I extracted with IMS B702t26.5 basket with 15g grounds, no channeling!
And the espresso tasted fine.
But I got a weird puck, don't know why.

Tbrandt1996
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Posts: 43
Joined: 5 years ago

#12: Post by Tbrandt1996 »

Looks like the water flow from the machine is digging a hole on the right side of the basket. I would check to make sure the shower screen is seated correctly, clean and free of damage. Also check the group seals are in good shape and clean, coffee oils can combine with the piston seal lubricant and make a pretty nasty sludge. Just to make sure the machine isn't what is causing your troubles.

Also make sure your distribution is even and tamp is level. I noticed that I needed to tamp significantly harder on my La San Marco group machine than what I was used to from my previous E61 machine to get a good seal around the basket edges and prevent donut extractions. You may need to adjust your puck prep to find what works with the lever machine.

LObin
Posts: 1793
Joined: 7 years ago

#13: Post by LObin »



Again, it's quite a forgiving lever machine...
Your spent pucks should look like this pretty much every time.

Have you checked your piston seals and shower screen yet?

Are the burrs on your Lagom seasoned?
LMWDP #592

irvingggg (original poster)
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Joined: 3 years ago

#14: Post by irvingggg (original poster) »

Thank you for replying!!
I always remove the portafilter after steaming milk, so the pressure might be released.

I did wdt, and tried to tamp even, cannot think of anything wrong at this step.
The puck was not good since I got this L1, so I just replaced new shoer screen not long ago. I suggest the new shower screen is in good condition.
I open my group head today to check if the piston seals are dead, but cannot tell their condition by eyes :lol:


It's not easy to buy new seals in my country.
But I think I am gonna order a new set of seals, including piston and group ones.
I wish I can make the machine work 100% good!

LObin
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Joined: 7 years ago

#15: Post by LObin »

You can remove the bottom seal and flex it between your thumb and index so it creates an "8". If the seal bends easily without force or signs of failure (cracks) it should be ok.

From the picture, you definitely need to apply lubricant though. If you order from Reiss, get some replacement seals and lubricant all together. Keep in mind the seals last about 12 to 18 months.

The new Cafelat blue lever seals could also work. Silicone so longer life span.

Another very popular lubricant is Molykote dow 111. See if you can find some locally.

Not sure what you mean by removing the portafilter while steaming though. Unless the lever is locked down in preinfusion position, no water nor steam pressure coming from the boiler is going to the puck. The water from the thermosyphon circulates between the 2 top piston seals until the piston is raised by lowering the lever. During the extraction, the water trapped between the coffee puck and the piston is pushed through the puck.
When making lattes, I always steam during the extraction. No worries here!

Cheers!
LMWDP #592

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baldheadracing
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#16: Post by baldheadracing »

irvingggg wrote:Then I extracted with IMS B702t26.5 basket with 15g grounds, no channeling!
And the espresso tasted fine. ...
Okay, good! :D

I'd suggest sticking to the 15g dose and that particular basket until you get consistent results.
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

hege
Posts: 37
Joined: 13 years ago

#17: Post by hege »

How fast are you pulling the lever down? It needs to be done very carefully, because the initial lifting of the piston will suck air in through the coffee puck (after half-way water will come in and create pressure). Abrupt pull will literally lift the puck out from the basket and let the water go around the edge where there is no adhesion any more.
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LObin
Posts: 1793
Joined: 7 years ago

#18: Post by LObin replying to hege »

That's a sound advice. However, the OP's extraction problems are likely caused by something else imo.

Think about it... Dritan Alsela has the same group on his Vibiemme lever machine and he pulls the lever like there's no tomorrow :)

Bet you he's not pulling super light rosted SO though giving how detailed you have to be with your prep and technique...

OP, any progress?
LMWDP #592

irvingggg (original poster)
Posts: 7
Joined: 3 years ago

#19: Post by irvingggg (original poster) »

Channeling during pre infusion has been solved.
But I felt that I am not making great espresso :cry:

I replaced the piston gaskets and group gasket which are made by Cafelat.
They fit well with L1, and have more elasticity.
But I still kept pulling bad espresso which had only little body and crema lasting not long.
Also, I always got cracked pucks after extraction.

I also ordered 14g/21g EP hq baskets, but even got worse results :cry:
So I went back to IMS 26.5 basket with 15g dosage.

I had read about LObin's old article in which LObin found the problem to be water scale inside the thermosyphon.
Would LObin please teach me how to clean it?
Thank you very much :)



LObin
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Joined: 7 years ago

#20: Post by LObin replying to irvingggg »

Oh man! Here I am assuming it's technique, seals, baskets or shower screen related.... how can I forget about my own journey!

The L1 thermosyphon is quite small at one point which is where the injector is located. It's inside this fitting:


With the assistance of Reiss, I removed the boiler from the machine, freed it from every pipe and valve and then worked on that fitting which was a bit of a job to remove. Cleaned and descaled it as well as the boiler and reassemble.

You could try to simply descale the machine first although Reiss is not a big fan. Other L1 owners have done it without any issue. If you were to go that route, I would fill the boiler manually, with the machine off and rinse it very thoroughly after. You don't want the descaling solution to damage the chrome inside the group and group sleeve.

There's a thread on the Londinium forum with more details of my adventure.

Also, if you're going to be removing valves or copper tubes on your L1, be sure to use the hammer and wrench technique. You don't want to apply high force at the end of a wrench with a boiler that's not screwed/attached to the frame.

Let me know if I can help more!

Cheers!
LMWDP #592