Screens - when to replace them?

la marzocco, synesso, simonelli, cimbali etc

Screens - when to replace them?

Postby Mike Gregory on Mon May 15, 2006 10:30 am

What indictators should I be looking for to determine if it's time to change the screens on my Linea?
Mike Gregory
 
Posts: 177
Joined: Wed Apr 05, 2006 9:28 pm
Location: Seattle
full name: Mike Gregory
company: Independent

Postby Alistair Durie on Mon May 15, 2006 10:42 am

i like to change mine every month.

the two layers of the screen should lay flat against each other. over time and especially if you are updosing the layers will seperate and grinds will get caught in between.

they are about $4, change them all the time, its well worth it.

i suggest having two sets of screens. in the afternoon we can quickly swap out the screens for some that are clean and have been soaking in detergent.
Alistair Durie
Elysian Coffee | photos | tweets
Alistair Durie
admin
 
Posts: 1002
Joined: Sun Aug 15, 2004 1:59 am
Location: Vancouver Canada
full name: Alistair Durie
company: Elysian Coffee
: www.elysiancoffee.com
: www.coffeed.com

Postby Mike Gregory on Tue May 16, 2006 1:02 pm

When the screens are screwed flush against the block, doesnt that keep the screen's mesh and plate layers pressed together even if they've seperated? Have you actuually noticed differences in extraction?
Mike Gregory
 
Posts: 177
Joined: Wed Apr 05, 2006 9:28 pm
Location: Seattle
full name: Mike Gregory
company: Independent

Postby Alistair Durie on Tue May 16, 2006 2:27 pm

when the screw is in place there is the space for the water to exit the screw before it goes through the screen. if forced, the screen will 'pop up' into that space. it can get really messy.

i notice a great improvement in my extractions whenever i swap out my screens for clean ones, and when i change to new ones.
Alistair Durie
Elysian Coffee | photos | tweets
Alistair Durie
admin
 
Posts: 1002
Joined: Sun Aug 15, 2004 1:59 am
Location: Vancouver Canada
full name: Alistair Durie
company: Elysian Coffee
: www.elysiancoffee.com
: www.coffeed.com

Postby onocoffee on Tue May 16, 2006 7:18 pm

I think this is an interesting question and one that I've pondered myself from time to time.

After awhile, I've noticed screens getting clogged with coffee debris. If you simply soaked the screens in a high-concentration cleaning solution and dissolved those solids away would the screen not be suitable for use?
Jay Caragay

Lono
new explorations in coffee + cuisine.
onocoffee
 
Posts: 1209
Joined: Fri Jul 15, 2005 1:30 pm
Location: Towson, MD
full name: Jay Caragay
company: spiral jetty
: www.sprocoffee.com
: onocoffee.blogspot.com

Postby Brent on Tue May 16, 2006 9:09 pm

onocoffee wrote:After awhile, I've noticed screens getting clogged with coffee debris. If you simply soaked the screens in a high-concentration cleaning solution and dissolved those solids away would the screen not be suitable for use?


In theory yes, but then what about the effect of the heat on the screens etc over time. Does a flat screen make a difference versus one that has been used and abused?

Personally, if I can't clean the screen in whatever time I have allocated myself, I change it.

With a screen being not a lot different in price to a head gasket, is there any reason not to change them periodically anyway?
Brent
Brent
 
Posts: 461
Joined: Tue Aug 09, 2005 6:23 pm
Location: New Zealand
full name: Brent
company: .

Postby Mike Gregory on Wed May 17, 2006 12:32 am

alistair wrote:the two layers of the screen should lay flat against each other. over time and especially if you are updosing the layers will seperate and grinds will get caught in between.


I replaced all my screens last night, and tonight I noticed 2 of 3 were seperated already, though pushing the more solid half of the screen downwards against the mesh half seems to keep the two together. They could however become seperated while screwed into the machine with enough pressure applied. I compared these 24 hr old screens against a second set of new screens, all of which were not plyable enough to seperate (don't know if the temperature difference, room vs 200, made a significant difference here). Is it normal for the screens to seperate after such little use? Why are they fused only around the outer perimiter? Are there more robust ones on the market?

alistair wrote:i like to change mine every month.


Based on the past day of operation on my machine, it looks like they would need to be changed at least daily if there is indeed a significant difference in extraction...

And ESI charges a little over USD $5 dollars each. Are you getting them for CAN $4?
Mike Gregory
 
Posts: 177
Joined: Wed Apr 05, 2006 9:28 pm
Location: Seattle
full name: Mike Gregory
company: Independent

Postby Alistair Durie on Wed May 17, 2006 7:27 am

Be sure only to tighten the screw finger tight, snug againsts the screen no more than that.

If your screens are popping up you must be updosing.

Espressoparts.com sells them for about $4.20
Alistair Durie
Elysian Coffee | photos | tweets
Alistair Durie
admin
 
Posts: 1002
Joined: Sun Aug 15, 2004 1:59 am
Location: Vancouver Canada
full name: Alistair Durie
company: Elysian Coffee
: www.elysiancoffee.com
: www.coffeed.com

Postby nick on Wed May 17, 2006 8:20 am

alistair wrote:If your screens are popping up you must be updosing.

Not necessarily.

There are manufacturing variances (apparently), and some screens will 'pop' up and stay 'popped,' sort of like a milk-cap... some don't.
You didn't think that this sort of thing only happened with baskets, did you? :wink:
nick
 
Posts: 1335
Joined: Thu Jun 23, 2005 8:15 pm
Location: San Francisco, Coffeefornia
full name: Nicholas Cho
company: Wrecking Ball Coffee Roasters
: http://nickcho.com
: http://wreckingballcoffee.com/

Postby Alistair Durie on Wed May 17, 2006 11:45 am

ok, so if all of your screens are popping up you are probably updosing.
Alistair Durie
Elysian Coffee | photos | tweets
Alistair Durie
admin
 
Posts: 1002
Joined: Sun Aug 15, 2004 1:59 am
Location: Vancouver Canada
full name: Alistair Durie
company: Elysian Coffee
: www.elysiancoffee.com
: www.coffeed.com

Postby Philip Search on Wed May 17, 2006 2:17 pm

Not all screens are equal ether. I recieved a batch of special screens from an equiptment guy at a local roaster, he got them from a shop that went out of biz or something... anyway these don't have the little band that holds the mesh to the back, but intead have a solid pece that goes up the edge. They also are made to a much higher tolerance, with a really nice tight fit to the group and a much higher grade of stailess for the back and the screen. I will try and borrow a camera tomorrow and snap a pic. I have found that these screens last about 3 times as long, clean up better, and have a nicer water dispersion. I only have three left and will be realy sad if I can't source more.
Philip Search
Philip Search
 
Posts: 88
Joined: Mon Nov 07, 2005 11:08 pm
full name: Phillip Search
company: The Devil's Cup

Postby Brent on Wed May 17, 2006 2:58 pm

alistair wrote:ok, so if all of your screens are popping up you are probably updosing.


No thats called a dodgy batch.

:?
Brent
Brent
 
Posts: 461
Joined: Tue Aug 09, 2005 6:23 pm
Location: New Zealand
full name: Brent
company: .

Postby Mike Gregory on Wed May 17, 2006 4:29 pm

Coffeeparadise wrote:I only have three left and will be realy sad if I can't source more.


I'm concerned here that my screens 'popped' after a day of use, and I <i>really</i> dont think an appropriate solution would be to change dosing technique. Can anyone offer more insight, or does anyone besides Phillip use a non-factory screen?
Mike Gregory
 
Posts: 177
Joined: Wed Apr 05, 2006 9:28 pm
Location: Seattle
full name: Mike Gregory
company: Independent

Postby Philip Search on Wed May 17, 2006 9:26 pm

Something else I was thinking about, what gasket you use thickness wise will effect the amount of pressure on the screen; while this will also will change the profile some, there maybe a happy medium.
Philip Search
Philip Search
 
Posts: 88
Joined: Mon Nov 07, 2005 11:08 pm
full name: Phillip Search
company: The Devil's Cup

Postby Brent on Thu May 18, 2006 1:32 pm

Coffeeparadise wrote:Something else I was thinking about, what gasket you use thickness wise will effect the amount of pressure on the screen; while this will also will change the profile some, there maybe a happy medium.


And I was reliably told that the manufacturing tolerances on the gaskets are pretty loose.

just to add some good old confusion :)
Brent
Brent
 
Posts: 461
Joined: Tue Aug 09, 2005 6:23 pm
Location: New Zealand
full name: Brent
company: .

Postby Mike Gregory on Tue Oct 17, 2006 8:45 am

Coffeeparadise wrote:Not all screens are equal ether. I recieved a batch of special screens from an equiptment guy at a local roaster, he got them from a shop that went out of biz or something... anyway these don't have the little band that holds the mesh to the back, but intead have a solid pece that goes up the edge. They also are made to a much higher tolerance, with a really nice tight fit to the group and a much higher grade of stailess for the back and the screen. I will try and borrow a camera tomorrow and snap a pic. I have found that these screens last about 3 times as long, clean up better, and have a nicer water dispersion. I only have three left and will be realy sad if I can't source more.


Phillip, any news on these? I'd love to see a picture too.

Has anyone tried nuovo simonelli screens on an LM? They seem to be built much more robustly than LM screens, but I'm concerned the ridge around the screwhole may block the water exit hole in LM's dispersion screw. Nuovo Simonellis disperse via 8 or so showerhead-style holes in the dispersion block centered around the screwhole.
Mike Gregory
 
Posts: 177
Joined: Wed Apr 05, 2006 9:28 pm
Location: Seattle
full name: Mike Gregory
company: Independent


Who is online

Users browsing this forum: No registered users and 2 guests