Conti Prestina Espresso Machine Restoration 101 (Completed and Indexed) - Page 48

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
jonny

#471: Post by jonny »

TomC wrote:I might look for that thread sealer as an option for attaching my Richard Penny bottomless portafilter to the Cremina handle.

I don't want to use blue loctite or anything too hard to undo.
Tom, I would be careful about that if I were you. I put a wood handle on a Penney pf and after it shrunk a little bit, it has been impossible to remove without cutting the wood off. Attempting to unscrew the handle will end up unscrewing the the shaft from the pf body and then that little shaft is nearly impossible to grip properly. Maybe this stuff is soft enough to not provide too much rotational resistance, but beware.

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drgary
Team HB

#472: Post by drgary »

It's pretty soft but I think PTFE tape is a better and cheaper solution and more easily removed than the rubber cement-like residue that would be left in the threads.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

jedovaty

#473: Post by jedovaty »

How about something like this:
http://cleanfit.com/blue_monster_stay-s ... 6023.shtml

They also have this:
http://cleanfit.com/blue_monster_indust ... 6001.shtml

Which comes in both ptfe and non-ptfe flavors. I am averse to using any ptfe.

I'm not sure about this product:
http://cleanfit.com/blue_monster_nickel ... cant.shtml

coelcanth

#474: Post by coelcanth »

isn't it possible to assemble these brass fittings using no sealant at all ?

i thought they were designed with that intent

that is how i rebuilt my Cremina,
no problems so far...

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drgary
Team HB

#475: Post by drgary »

It is possible. Since I'm new at this I'm taking precautions. I believe there are differences in fittings too. There are some where the pipe inserts into the female piece and is sealed off with a cap. I'm told those don't need solder or sealant. There are others where the fitting and a ferrule meet a flat female surface. I believe a gasket is needed there, so I've created a couple of Teflon gaskets for those connections. There are some where there's no pipe or cap and where PTFE tape is required. An alternative to that tape is PTFE paste or a sealant like I'm using. The sealant is an extra step but is as easy as smearing honey on the threads and then it doesn't harden into something difficult to remove. Maybe someone with more knowledge can specify what needs sealant and what doesn't.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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RayJohns

#476: Post by RayJohns »

coelcanth wrote:isn't it possible to assemble these brass fittings using no sealant at all ?

i thought they were designed with that intent

that is how i rebuilt my Cremina,
no problems so far...
It depends on the fittings. If there are copper sealing washers involved, then usually you can assemble them with not sealant. If not, then I, personally, use a little bit of Teflon tape around the threads to effect a pressure tight seal.

Ray

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erics
Supporter ◈

#477: Post by erics »

As an FYI, this is what Sirai has to say regarding their pstats. Drawing taken from their pdf of the P302-8 pressurestat.

Image
The pressure switch can be mounted in any position, but the mounting with vertical axis and pressure intake as per scheme is suggested. This to avoid that the boiler deposits obstruct the pressure pipe.

The regular cleaning of components with a suitable lubrication of mechanical parts can guarantee optimum
performances and functioning in the lifetime.
As regards all of these fittings and tubing, etc., etc., I would assemble everything with no soldering and no sealant in a handtight condition FIRST. Make sure you have no accessibility issues, i.e., sometimes making a tube 1/8" longer or shorter or bending it up vice down can make all the difference one can imagine.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

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drgary
Team HB

#478: Post by drgary »

erics wrote:As regards all of these fittings and tubing, etc., etc., I would assemble everything with no soldering and no sealant in a handtight condition FIRST.
Eric:

Are you suggesting this to test the soundness of the connections? I understand there's a purpose to your suggestion. Just don't know what it is.
erics wrote:Make sure you have no accessibility issues, i.e., sometimes making a tube 1/8" longer or shorter or bending it up vice down can make all the difference one can imagine.
What are guidelines for bending that avoid accessibility issues? What kinds of bends cause problems?

(Perhaps we need an Espresso Machine Plumbing 101 thread.)
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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erics
Supporter ◈

#479: Post by erics »

The integrity of the joints will be tested after you start her up. I was simply suggesting a "dry run" to see how it all fits together in place.

A reasonable guide for bending tubing is that the bend radius should be no less than three times the tube diameter but this is mainly to avoid excessive stress in the tube.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

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drgary
Team HB

#480: Post by drgary »

So when you wrote "make sure there are no accessibility issues" were you saying simply to make sure the tubing fits where the components are placed?
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!