conti lever rebuild question - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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mogogear
Posts: 1482
Joined: February 20th, 2006

Postby mogogear » Aug 10, 2006, 5:52 pm

Too many! A Cremina, a Caravel, playing with a couple of Astra Gourmets and a Isomac Tea. My large format lever is a 1977 Gaggia Compacta Palanca that has been getting modernized( she is brand new and never been installed- prior to bench testing in the last month)
greg moore

Leverwright
LMWDP #067

jeru
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Joined: February 10th, 2006

Postby jeru » Aug 15, 2006, 11:01 am

Well, I'm very slowly making progress with the new Conti (Painting the House has been dominating the top of the priority list lately). I have a new set of piston seals and I pulled apart the piston assembly that appeared to be leaking. That was actually super easy. Cleverly, the spring/piston/leverage system is mechanically self contained so that you can take it out without releasing the preload force on the spring. It looks pretty good in there. There is white gunk which I assume is old lube and it could use a moderate cleaning. It's amazing how simple the whole thing is! You can look straight down from the top and through the group screen on the bottom.

Quick question though (or maybe two) - my plan was to scrub the whole piston and cylinder area down with a plastic brush and some Cafiza? Sound good? Second, I searched on this forum regarding lubricant and it looks like there are quite a few options. I currently have a "Sanitary Petrol Gel Lubricant, NSF Approved" from espressoparts.com but there seemed to be an anti-petrol sentiment in the posts. Should I NOT use the lube I have and try to locate a different lube, like Dow 111? Or should the lube I have be fine?

Thanks again (pictures coming, I promise!)

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mogogear
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Joined: February 20th, 2006

Postby mogogear » Aug 15, 2006, 5:26 pm

Depends on what you lube. I think lube is percieved as OK here, it is the WHAT WITH and HOW MUCH get the discussion posts. New piston seals need a touch of lube to aid in re-assembly etc. Lever linkage etc can also benefit. It is the old addage a little good- alot must be real good- that we are all on the guard against. So with prudence you should be fine, normally just a film of lube works just fine.

Clean away
greg moore

Leverwright
LMWDP #067

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timo888
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Joined: February 28th, 2006

Postby timo888 » Aug 28, 2006, 6:17 am

jeru wrote:Second, I searched on this forum regarding lubricant and it looks like there are quite a few options. I currently have a "Sanitary Petrol Gel Lubricant, NSF Approved" from espressoparts.com but there seemed to be an anti-petrol sentiment in the posts. Should I NOT use the lube I have and try to locate a different lube, like Dow 111? Or should the lube I have be fine?



To lubricate parts exposed regularly to water near boiling, I would use Dow 111 instead because the Petrol-Gel's melting point is 195°F.

Regards
Timo

Petrol-Gel Sanitary Lubricant
by McGlaughlin Oil Co.

* Tasteless and odorless
* Will not taint
* USDA Rated H-1
* FDA approved
* Impervious to water
* Operating Temp 0° - 185°F
* High melting point of 195°F

* Technical white grease
* Valves, pistons, pumps
* O-rings, guides, slide mechanisms, and more



UPDATE:
I would also prefer Dow 111 (NSF 51 and NSF 61 approvals) to this product:
Haynes Lubri-Film Plus

The maximum operating temperature of this Haynes NSF H1-rated ("incidental contact") lubricant is 210°F.
Tech Specs

jeru
Posts: 14
Joined: February 10th, 2006

Postby jeru » Sep 04, 2006, 3:49 pm

ok, I finally got this machine set up. I've been having some fun with it this weekend. Here's a pic of one of the cleaned up piston assemblies:

Image

Here's the cleaned cylinder:

Image

And here's the machine on the counter in the kitchen:

Image

The one thing I've noticed so far is that the boiler pressure stat is set pretty high - just under 1.5bar. The machine is not a gravity feel fill, so it needs pressure to fill the chamber, but it seems like that's really hot. Can anyone out there make recommendations for boiler pressure?

Thanks!

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bill
Posts: 491
Joined: November 24th, 2005

Postby bill » Sep 04, 2006, 6:36 pm

I've got my Prestina with same group as yours set at 0.8 to 1.0.
Bill
LMWDP #43

I wasn't born in Texas, but got here as fast as I could!

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timo888
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Joined: February 28th, 2006

Postby timo888 » Sep 04, 2006, 8:19 pm

jeru wrote:ok, I finally got this machine set up. I've been having some fun with it this weekend. Here's a pic of one of the cleaned up piston assemblies:

image: /forums/userpix/846_pistonsmall_1.jpg

Here's the cleaned cylinder:

image: /forums/userpix/846_cylindersmall_1.jpg

And here's the machine on the counter in the kitchen:

image: /forums/userpix/846_installationsmall_1.jpg

The one thing I've noticed so far is that the boiler pressure stat is set pretty high - just under 1.5bar. The machine is not a gravity feel fill, so it needs pressure to fill the chamber, but it seems like that's really hot. Can anyone out there make recommendations for boiler pressure?

Thanks!



Nice photos, thanks.

Did you by any chance note the dimensions of the spring? Inner diameter? Thickness of metal? Length? And the diameter of the piston?

Boiler pressure is set to give good steam, but you can lower it as much as you like as long as there is enough pressure to bring water into the piston chamber and to produce steam to meet your milk-foaming demands, if there be any.

Regards
Timo

hperry
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Joined: August 14th, 2005

Postby hperry » Sep 04, 2006, 10:05 pm

I suspect that boiler pressure and the resulting coffee temperature varies from machine to machine. At 1.25 on the Termozona/Brugnetti three pulls brings me up to a pretty steady 200 degrees (Scace).

While temperature is not irrelevant, with a commercial lever it doesn't seem to have as much effect on coffee taste within a band of say 197 to 202 degrees as it does with a rotary or vibe pump machine. Don't know just why. Joe Kitay at the Good Coffee Company in Seattle, who has sold and repaired a lot of them likes to stay within .8 to 1.2.
Hal Perry

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mogogear
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Joined: February 20th, 2006

Postby mogogear » Sep 04, 2006, 11:00 pm

Jeru,
You just make a Oregonian proud!! You have got the best home settup in the County!! That was a nice rescue from the kid who had it here in Portland!! It looks great in your house! I now know that in case of emergency, if in Corvallis, there is a great shot to be had!!
greg moore

Leverwright
LMWDP #067

hperry
Posts: 877
Joined: August 14th, 2005

Postby hperry » Sep 04, 2006, 11:11 pm

Jeru,

Mogo's response reminds me that I meant to note on my previous response that your setup is really impressive. That machine is obviously "preening its feathers!"
Hal Perry

 
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