Basket sticks to gasket. New gasket-which one?

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#1: Post by Vindibona1 »

I've been enjoying my Quick Mill QM67 for a few months and all seems to be well, except that I have a perplexing problem. The basket in my naked portafilter regularly gets stuck to the gasket. So from time to time when I remove the PF the basket remains attached. Usually I can just take a paper towel, reach up and push the basket a bit and it frees iteself and drops out. Once in awhile it's stuck to the gasket like glue.

FWIW I am very fastidious about keeping things clean. The rim of the basket is wiped before and afte every pull. I have a brush that fits inside the head to brush out any ground or debris from inside the head and on the gasket and use it regularly, though not every day. Every couple of days I remove the gasket and shower screen and clean those, paying particular attention to the gasket. Even right after cleaning on the next pull the basket might stick and I have to "encourage" it manually to drop out of the head.

While this is obviously not a critical issue, it's just annoying. And for the most part gaskets are pretty cheap, most seem to cost under $10 USD. Reasonable price isn't an issue. So should I just change out the OEM gasket for something else? I know that there are some gaskets that are softer than others. The OEM one is hard rubber(?). Not sure what the substance is. There are "silicone" gaskets in different colors, so presumably softer.

1) Should I replace the gasket?
2) What brand or material? Does the material matter which thickness?
3)8mmm or 8.5mm based on answer to Q2?

Thanks in advance for the advice


#2: Post by iyayy »

im not really sure if gasket should be squeky clean or have some food grade grease. someone can maybe chime on this.

but have you tried bending the spring in ur portafilter to make it hold the basket tighter? its just a piece of metal that sits inside a groove. u can take it out and and bend bit more angle, its pretty hard and springy btw. i actually straightened mine instead, since i swap singles basket regularly and it originally was too tight for my liking but i never had basket sticking.

Vindibona1 (original poster)

#3: Post by Vindibona1 (original poster) replying to iyayy »

The spring could be a bit tighter. But I think it's often more than the spring tension. There was one time this week where the basket seemed "hermitcially sealed" to the gasket. Usually a slight push moves it enough to drop out. This one time it took me pushing with my palm while grasping onto the backside of the group head with my fingers, having to apply far more force than should ever be necessary.

Food grade grease, eh? Hmmm.... Interesting. I never had the issue with my Gaggia Classic with this very same IMS basket.

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#4: Post by baldheadracing »

It isn't clear to me how often you lubricate the gasket, what lubricants you use, etc.

Regardless, in answer to your questions, you have to measure your existing gasket's thickness. Cafelat and Caffewerks are well-known brands of silicone gaskets. The main disadvantage of silicone is that the material tears more easily than rubber so you are more likely to destroy the seal when removing the seal for maintenance and lubrication. The main advantage is that silicone doesn't need anywhere near as much regular maintenance and lubrication as rubber. Lots of people stop maintenance and lubrication of silicone seals entirely, and just replace the silicone seals when the seals get brittle.
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

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#5: Post by mckolit »

On my qm67 I bought the 8.5mm silicone gasket. Didn't have an issue with the baskets sticking to the original gasket. Are your baskets loose on the portafilter? When I clean out the baskets, I can't pry them off the portafilter with just my fingers.


#6: Post by Davi-L »

I found with my QuickMill that the factory rubber gasket became hard very quickly. I bought the red and blue silicone gaskets, and they are much smoother to twist and lock and easy to remove for cleaning. Thickness depends on where you want to lock the portafilter. The inherent shower screen size is such that found I had a titch more headroom with the thicker gasket.
Speaking of headroom, if you overdose the baskets and the coffee swells, it can fasten to the shower screen. Keep some space available.
When you finish the shot, move the lever to Park or middle position. Let the basket depressurize by itself into the drip tray. Unless making back to back shots, quickly moving the lever to flush will cause the basket contents to bind to the shower screen. I just flush into the tray and rarely use the blind basket.


PS, only tighten the portafilter enough to prevent leaks. Too much and the basket merges with the gasket.