When flushing (without portafilter) IMS 35 micron shower screen detaches under water force and falls on the tray. I did not notice this happening the first 3-4 weeks of owning this machine. Any way to prevent this? Lube, hammer...?
you will find people who will take your experience as evidence that the IMS 35 micron screen is a poor choice and that the IMS 200 micron screen is a better choice
this may be true for pump machines that suck coffee upwards through the screen when the pump turns off, but it is not the case for lever machines
it is caused by a portion of the screen becoming blocked
if it occurs when the machine is relatively new it is due to excess silicone grease travelling down and fouling in the screen, which in turn elevates the pressure above the screen and if sufficiently it will blow the screen completely off
to remedy remove the screen and place it in a small bowl/similar and add a citrus solvent and allow it to soak for a while, agitating the screen in the solvent every few minutes and perhaps using an old disused toothbrush or similar to work the solvent gently into the screen
if you want to take the old school approach use Acetone
i dont know of any other products that dissolved silicone grease - it is really difficult to fully remove
then rinse thoroughly under a fast running cold tap with copious amounts of water
if the screen is older and you are time poor just replace it - if you are replacing the screen it is common practice to replace the gasket at the same time as these harden with the heat they are exposed to
the screen will eventually become clogged with coffee tars, but unless you are putting more coffee in the basket than it was designed to carry, such that you end up with coffee pushed up against the shower screen it should take many months, so i dont see it as a particular chore
the reduction in the water surge into the brew chamber with the 35 micron screen is more than worth the inconvenience of having to clean the screen a couple of times a year
That makes sense, it's probably the silicone grease. I soaked it in citric acid for 20-30 min and there was still some left. I'll try leaving it for longer and try acetone if that doesn't work. Now when I hold the basket in my hand and fill it up with water, it barely drops through... but that might be by design.
I like the IMS screen, it mostly stays clean with 18g of coffee.
watching your video i suspect you have not driven the screen on firmly enough
in the first step where you use the portafilter with basket removed to drive the screen into place you push the handle around to the necessary angle
but in the second step where you add the basket back into the portafilter to effectively increase the extent to which you can drive the screen up into the seal groove you only push the portafilter handle slightly to the right of 6 o'clock
you need to drive the portafilter handle with the basket in as far to the right as you drove it in step one when the basket was not present
hold the right hand side of the group with your right hand and drive the portafilter handle to the right with your left hand if this helps you to get more purchase
let me know
when you finish the bottom of the portafilter seal should be as close to flush with the bottom of the groove of the seal groove that it lies in as possible - perhaps 1mm still hanging down
if you achieve this and you have cleaned and rinsed the shower screen it should stay in place, unless the seal has become hard and rigid with heat, as frans mentions
Reiss - IMS screen appears clean, light shines through, I left the screen in Acetone for an hour, boiled it in water and citric acid. Thing is, even with all this force wnen putting it on I can take it off with my bare hands using little effort. So, I did what you suggested, I used more force in both steps to the point I was moving the machine, ring almost flush with the piston, perhaps 0.5mm sticking out. I pull the lever but the screen pops off again. Here is the video
Frans - I tested the stock Londinium screen and it stayed on after 2-3 flushes. I’ll report back if itstarts slipping too. Here’s the vid